ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (114,651)
  • Springer  (105,795)
  • American Association for the Advancement of Science (AAAS)  (8,856)
  • American Institute of Physics (AIP)
  • 1995-1999  (103,080)
  • 1950-1954  (11,571)
  • Biology  (114,651)
Collection
  • Articles  (114,651)
Source
Keywords
Publisher
Years
Year
Journal
Topic
  • 1
    Electronic Resource
    Electronic Resource
    Comparison of antennal sensilla of Anaphes victus and A. listronoti (Hymenoptera, Mymaridae), egg parasitoids of Curculionidae (1999)
    Springer
    Zoomorphology 119 (1999), S. 1-8 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Antennal sensilla were compared in females and males of two sympatric mymarid Hymenoptera, Anaphes victus and A. listronoti which are, respectively, solitary and gregarious parasitoids of eggs of the carrot weevil Listronotus oregonensis (Coleoptera, Curculionidae). Both species are morphologically very similar in the area where they are sympatric. The external morphology of the sensilla was studied using scanning electron microscopy. Female antennae have seven different types of sensilla, morphologically similar in the two species: trichoid sensilla, which are putative mechanosensilla, sensilla chaetica types 1, 3 and 4, which are presumably contact chemosensilla, and sensilla chaetica type 2 and basiconic and placoid sensilla, which are presumed to be olfactory sensilla. The major difference between the two species is the number of sensilla chaetica type 4, of which 6–9 are found on the antennal club in A. victus, while 10–12 are present in A. listronoti. The antennae of the males of both species are similar in morphology and in the number and distribution of their four types of sensilla, i.e. trichoid sensilla, sensilla chaetica type 1 and basiconic and placoid sensilla.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004350050076
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Morphology and morphometrics of the appendicular musculature in geckoes with different locomotor habits (Lepidosauria) (1999)
    Springer
    Zoomorphology 119 (1999), S. 9-22 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  In this study a ground-dwelling (Eublepharis macularius) and a highly specialised climbing (Gekko gecko) lizard were chosen as study objects. The fore- and hindlimbs of two individuals of each species were dissected, and muscle masses, mean fibre lengths, cross-sectional areas and moment arms were determined. Special attention was paid to general muscle architecture (origin, insertion, fibre orientation, etc.) and pennation angles. Using these variables (cross sectional areas and moment arms), maximal moments exertable across the shoulder/hip, elbow/knee and wrist/ankle were calculated for both species. In accordance with the biomechanical predictions related to the preferred locomotor substrate of each species (i.e. level running for E. macularius and climbing for G. gecko), the results of this study indicate that climbers such as G. gecko generally possess powerful retractor muscles crossing the shoulder and hip joints. Additionally, the specialised climber is able to exert higher flexion moments across the elbow, which prevents the animals from falling backwards. However, G. gecko appears to be constrained in its ankle extension capabilities by the presence of the adhesive toe pads. The level-running species, on the other hand, shows a relatively stronger development of the extensor muscles in the lower limbs, allowing these lizards to run in an erect posture. In general, both species show large similarities on a gross morphological level as expected when considering their phylogenetic relatedness. Adaptations to their preferred locomotor substrate only become apparent when considering the functional properties (i.e. joint moments) of the appendicular musculature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004350050077
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Larval and metamorphic skeletal development in the fast-developing frog Pyxicephalus adspersus (Anura, Ranidae) (1999)
    Springer
    Zoomorphology 119 (1999), S. 23-35 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Pyxicephalus adspersus , is exceptional among living frogs. Embryonic development, larval phase, and metamorphosis can be completed in 17 days at a temperature of 29°C. The metamorphosis only takes 5 days. The present study shows that, despite the unusually short larval phase in P. adspersus, the state of skeletal differentiation reached at the end of metamorphosis is similar to that of other frog species. There is no shift of cranial bone formation postmetamorphosis as could have been expected and is known from other species. The majority of compared species are particularly similar in the sequence of bone formation in the postcranial skeleton. However, there are clear differences among species in the timing of these events relative to the larval growth trajectory, absolute time, and certain developmental markers, such as external limb differentiation. For example, skeletogenesis and externally visible limb differentiation are only loosely integrated. Interspecific comparisons show that, in P. adspersus, the early onset of skeletal ossification is an unusual feature among frogs. Freshly metamorphosed froglets of P. adspersus are already distinct from comparable stages of other species in having strong jaws, fang-like teeth, and a squamosal-maxilla contact. The latter stabilizes the maxillary arcade and the suspensorium and might relate to the ability to catch and swallow very large vigorous prey, such as siblings, shortly after metamorphosis. The presence of a complete set of dermatocranial elements and postmetamorphic ossification of only the sphenethmoid and operculum are considered plesiomorphic features, whereas the much less completely ossified skulls of metamorphosed froglets, particularly in Bufo and Hamptophryne, are likely apo- morphic developmental traits within the Anura.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004350050078
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    CLSM analysis of development and structure of the central nervous system of Enchytraeus crypticus (”Oligochaeta”, Enchytraeidae) (1999)
    Springer
    Zoomorphology 119 (1999), S. 37-47 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The phylogenetic position of the Clitellata within the Annelida is still in debate. It is unresolved whether they are a basal group, resembling the stem species of the Annelida, or a highly derived subtaxon, which evolved from a polychaete-like ancestor. A factor often ignored in this discussion is the site of the supraoesophageal ganglion (brain). Its position in the Clitellata, far behind the prostomium, can be regarded as a secondary structural adaptation to a life spent burrowing through relatively firm terrestrial substrates. Such a habit probably led to the complete elimination of prostomial appendages and a marked reduction in size of the prostomium, resulting in a displacement of the brain into following segments. This interpretation of the sequence of events corroborates the view that the Clitellata are a highly derived subtaxon of the primarily marine Annelida. The development of the central nervous system of Enchytraeus crypticus (”Oligochaeta”) was analysed by immunohistochemical methods in combination with confocal laser scanning microscopy. A detailed description of neural structures, including the formation and arrangement of segmental nerves, is given for significant developmental stages. Labelling of neural structures using antibodies against acetylated α-tubulin and serotonin clearly shows that the cerebral ganglion initially develops within the prostomium. In the course of embryonic development it is shifted backwards into segment III. Thus the posterior relocation of the brain, which is inferred as having occurred in the phylogeny of the Clitel- lata, can be demonstrated in the ontogeny of E. crypticus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004350050079
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Histochemical localization of FMRFamide, serotonin and catecholamines in embryonic Crepidula fornicata (Gastropoda, Prosobranchia) (1999)
    Springer
    Zoomorphology 119 (1999), S. 49-62 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Recent reports indicate that neuronal elements develop in early larval stages of some Gastropoda from the Pulmonata and Opisthobranchia prior to the appearance of any ganglia of the future adult central nervous system (CNS). The present study describes similar early neuronal elements in Crepidula fornicata. A posterior FMRFamide-like immunoreactive (LIR) cell with anteriorly projected fibers was observed in the trochophore stage. Additional FMRFamide-LIR and serotonin-LIR cells and fibers were found in the apical organ in the trochophore and early veliger stages. FMRFamide-LIR and serotonin-LIR projections to the velum and foot were also detected at this time. As the veliger developed, peripheral FMRFamide-LIR and later catecholaminergic cells were located in the foot region. Also during this stage, catecholaminergic cells and processes were observed near the mouth. In addition, this study tentatively identified the first serotonin- and FMRFamide-LIR cells and fibers within the developing ganglia of the adult CNS, which appeared in close proximity to the earlier developing elements. These observations are consistent with the hypothesis that, in addition to its presumed role in the control of larval behaviors, the larval nervous system guides the development of the adult CNS. Larvae from the class Bivalvia and other invertebrate phyla also have neuronal elements marked by the presence of FMRFamide, serotonin, and catecholamines, and, therefore, this study may provide additional insights into phylogenetic relationships of the Gastropoda with other representatives of the Mollusca and different invertebrate phyla.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004350050080
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Development of a unique eye: photoreceptors of the pelagic predator Atlanta peroni (Gastropoda, Heteropoda) (1999)
    Springer
    Zoomorphology 119 (1999), S. 81-91 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The eyes of different larval stages and juveniles of Atlanta peroni are generally composed of a cornea, a lens and a retina. In juveniles a distinct pigmented shield is visible and an enormous humour is located behind the lens. Larvae have only two sensory cells and the photoreceptors are of the ciliary type. In juveniles a striking feature is the shape of the retina. It is ribbon-shaped and new sensory cells are present which are arranged in three rows. The photoreceptors are of the ciliary type as well. Contrary to the arrangement in larvae, the ciliary plasmalemma in juveniles forms numerous lamellar stacks. In accordance with the sensory cells the stacks are organized in three parallel rows. The lamellae of adjacent stacks within a row overlap each other. The latter unique feature has not yet been found in any other representative of the Heteropoda. These findings demonstrate that (a) the eyes are altered during the development from larvae into juveniles, (b) the larval sensory cells are reduced and replaced by new sensory cells in juveniles and (c) the eyes of juvenile and adult A. peroni are well adapted for their life as visual predators.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004350050083
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Evolution of the metathoracic tympanal ear and its mesothoracic homologue in the Macrolepidoptera (Insecta) (1999)
    Springer
    Zoomorphology 119 (1999), S. 93-103 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Two independent methods of comparison, serial homology and phylogenetic character mapping, are employed to investigate the evolutionary origin of the noctuoid moth (Noctuoidea) ear sensory organ. First, neurobiotin and Janus green B staining techniques are used to describe a novel mesothoracic chordotonal organ in the hawkmoth, Manduca sexta, which is shown to be serially homologous to the noctuoid metathoracic tympanal organ. This chordotonal organ comprises a proximal scolopidial region with three bipolar sensory cells, and a long flexible strand (composed of attachment cells) that connects peripherally to an unspecialized membrane ventral to the axillary cord of the fore-wing. Homology to the tympanal chordotonal organ in the Noctuoidea is proposed from anatomical comparisons of the meso- and metathoracic nerve branches and their corresponding peripheral attachment sites. Second, the general structure (noting sensory cell numbers, gross anatomy, and location of peripheral attachment sites) of both meso- and metathoracic organs is surveyed in 23 species representing seven superfamilies of the Lepidoptera. The structure of the wing-hinge chordotonal organ in both thoracic segments was found to be remarkably conserved in all superfamilies of the Macrolepidoptera examined except the Noctuoidea, where fewer than three cells occur in the metathoracic ear (one cell in representatives of the Notodontidae and two cells in those of other families examined), and at the mesothoracic wing-hinge (two cells) in the Notodontidae only. By mapping cell numbers onto current phylogenies of the Macrolepidoptera, we demonstrate that the three-celled wing-hinge chordotonal organ, believed to be a wing proprioceptor, represents the plesiomorphic state from which the tympanal organ in the Noctuoidea evolved. This ’trend toward simplicity’ in the noctuoid ear contrasts an apparent ’trend toward complexity’ in several other insect hearing organs where atympanate homologues have been studied. The advantages to having fewer rather than more cells in the moth ear, which functions primarily to detect the echolocation calls of bats, is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004350050084
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Fibre type regionalization of forelimb muscles in two mammalian species, Galea musteloides (Rodentia, Caviidae) and Tupaia belangeri (Scandentia, Tupaiidae), with comments on postnatal myogenesis (1999)
    Springer
    Zoomorphology 119 (1999), S. 117-126 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  To investigate structural differences between propulsory and antigravity muscles, the spatial distribution of slow (type I) and fast (type II) muscle fibres in forelimb muscles of two species of small mammals was studied, Galea musteloides and Tupaia belangeri. Serial sections through complete forelimbs were prepared. Following histochemical fibre typing, the forelimbs were reconstructed three-dimensionally using product design software. Most forelimb muscles of both species showed a homogenous distribution of type I fibres. In the supraspinatus and triceps brachii (capita longum et laterale) muscles, however, a segregation of fibre types into ”fast” superficial areas and ”slow” deep regions was observed. Slow regions contained at least 60% type I fibres and were positioned along intramuscular extensions of the tendons of insertion. The functional implications of fibre type regionalization are discussed. An analysis of intramuscular fibre type distribution during postnatal myogenesis revealed no significant differences in muscle fibre differentiation between altricial and precocial juveniles. Differences in locomotor ability probably arise from heterochronic development of connective tissue components (endo- and perimysium).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004350050086
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Ultrastructure of spermiogenesis and spermatozoa in Bradynectes sterreri and remarks on sperm cells in Haplopharynx rostratus and Paromalostomum fusculum: phylogenetic implications for the Macrostomorpha (Plathelminthes) (1999)
    Springer
    Zoomorphology 119 (1999), S. 105-115 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The fine structure of spermiogenesis and spermatozoa in three species of the Macrostomorpha was studied, with emphasis on Bradynectes sterreri. Two centrioles appear during the development of sperm cells, at least in B. sterreri and Paromalostomum fusculum. Initially these organelles have a perpendicular position, but later they come to lie in line with each other. In P. fusculum, the differentiation of rootlet structures inserting on both centrioles was found. However, ciliary axonemes do not grow out, either in B. sterreri or in P. fusculum. These two species, and also Haplopharynx rostratus, have aciliated spermatozoa. The mature male gametes of B. sterreri are characterized by a filiform nucleus, numerous mitochondria, dense bodies irregular in shape, membranous lacunae, a pair of electron-dense lateral ledges and two sets of cortical microtubules in addition to a closed ring of microtubules in the posterior segment of the cell. Both lateral ledges do not originate from the centrioles. ’Lateral ledges’ or ’lateral bristles’ were not observed in spermatozoa of H. rostratus and P. fusculum. Such structures cannot be considered autapomorphic for the Macrostomorpha. The known spermatological characteristics contribute to elucidating the interrelationships of the Macrostomorpha. Haplopharynx and Macrostomida are sister groups. Spermatozoa with cortical microtubules separated into two sets are hypothesized as an autapomorphy of the Macrostomida. The two lateral ledges found in spermatozoa of B. sterreri are discussed to correspond to the pair of ’lateral bristles’ known from Macrostomum species, indicating a sister-group relationship of these two taxa. Apparently, the aciliated spermatozoa of Macrostomorpha species originated from biciliated male gametes. Hence, biciliated spermatozoa are not an evolutionary novelty of the Trepaxonemata, but of the Rhabditophora.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004350050085
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Functional morphology of musculature in the acoelomate worm, Convoluta pulchra (Plathelminthes) (1999)
    Springer
    Zoomorphology 119 (1999), S. 127-142 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Convoluta pulchra is a small worm living in the surface sediment of mud flats where it feeds on diatoms. It is roughly teardrop in shape with a ventral groove in which the mouth sits, and it can move in a variety of ways, readily distorting its body in bending, twisting, and turning motions. Fluorescently labeled probes for filamentous actin revealed the musculature in whole mounts of the worm. In the body wall, the musculature consisted of a grid of circular, longitudinal crossover (that is, with a longitudinal orientation in the anterior half of the body but arcing medially to cross over to the contralateral side of the body behind the level of the mouth), and a few diagonal fibers. Inside the body was a strong, irregular brush of muscles originating at the rostral tip of the body and anchoring laterally and posteriorly along the body wall, and strong dorsoventral muscles flanked the ventral groove. Two fans of muscles in the ventral and dorsal body wall reached posteriorly and laterally; that on the dorsal side originated at junctures of the dorsoventral muscles with the body wall and that on the ventral body wall originated from the mouth. By their positions, certain groups of muscles could be correlated with given movements: the crossover muscles with some turning motions and feeding, and the inner muscles with probing and retraction motions of the rostrum and with a tuck-and-turn motion the worm used to turn itself around. Electron microscopy showed numerous maculae adherentes junctions linking all muscle types and special junctions linking the musculature with the epidermis. The latter myoepidermal junctions were of dimensions larger than those of maculae adherentes and contained an interlaminar material which we believe represents islands of basal matrix comparable to basement membrane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004350050087
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    The adhesive devices in larvae of Lepidoptera (Insecta, Pterygota) (1999)
    Springer
    Zoomorphology 119 (1999), S. 143-162 
    Details
    ISSN: 1432-234X
    Keywords: Abbreviations L1, L2, L3: instars of larvae ; Lm: mature larva(e)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Adhesion to smooth surfaces by means of thin fluid lipid film was studied on living larvae of 71 species of Lepidoptera by a simple ”light reflection method”. The method made it possible to localize exactly the sites of adhesion and to estimate roughly the film thickness, within a certain range. Furthermore, it revealed the general presence of mobile lipid on the entire insect surface. The observations on living larvae were complemented by comparative structural studies of the adhesive parts with light and scanning electron microscopes on preserved specimens of 161 species. Specialized adhesive devices were found in great diversity on larval legs and prolegs, especially in larvae living in the open air on their food plants. Two main surface types of adhesive cuticle were found: (1) cuticle with a flexible smooth surface and (2) cuticle with very numerous small projections (microtrichia) with spatulate and recurved apices. Both the functional implications of the adhesive cuticular structure and the role of the adhesive fluid as well as the evolution of the adhesive devices are discussed. The adhesive effect is due to ”capillary” or meniscus forces.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004350050088
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Comparative morphology of tergal phragmata occurring in the dorsal thoraco-abdominal junction of ditrysian Lepidoptera (Insecta) (1999)
    Springer
    Zoomorphology 119 (1999), S. 163-183 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  A comparative SEM investigation of the transphragma representing the medioanterior margin of the first abdominal tergum in ditrysian Lepidoptera resulted in the establishment of a directed transformation series of gradual modifications. Most remarkably, an additional phragma, for which the term euphragma is proposed, must be assigned to the ground pattern of the Obtectomera. However, this assumption implies that a subsequent loss of the euphragma must be attributed to the ground patterns of the Axiidae, Copromorphoidea, Doidae, Papilionidae and the Hedylidae. On the other hand, a typical euphragma is also observed in the non-obtectomeran superfamily Sesioidea. Similarly, the phylogenetic significance of the presence of a much smaller circular phragma in the Choreutidae is not yet understood. Either the three taxa (Obtectomera, Sesioidea and Choreutidae) constitute a clade, and secondary modifications have obliterated the euphragma on a number of occasions, or the euphragma has been developed independently on more than one occasion. Potential autapomorphies of various subordinate taxa are also discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004350050089
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Functional morphology of the ovipositor in Megarhyssa atrata (Hymenoptera, Ichneumonidae) and its penetration into wood (1999)
    Springer
    Zoomorphology 119 (1999), S. 73-79 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Megarhyssa atrata (Pimplinae) is the largest species known amongst Hymenoptera. In its natural habitat, North America, it is a strict parasito¨ıd of Tremex columba (Hymenoptera, Symphyta, Siricidae). The para- site infests xylophagous host larvae buried in wood. The present work describes the complex movements of the ovipositor during oviposition and its flexibility ensuring the positioning of the stylus at the site of boring. These movements are made possible by the unfolding of the intersegmentary membranes (equipped with a secretory internal surface) and by the full rotation of abdominal segments 8 and 9. During this rotation, the stylus of the ovipositor pushes and extends the membranes completely which, as a result, form a translucent disc measuring 2 cm in diameter. The entry of the stylus into wood is helped by another secretion produced at the tip of the valvulae. This lytic secretion destroys wood fibers. With this set of adaptations, the hymenopteran can bore into a thickness of hard wood and reach its host larvae at a depth of 14 cm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004350050082
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Stellate cells in the Malpighian tubules of Drosophila hydei and D. melanogaster larvae (Insecta, Diptera) (1999)
    Springer
    Zoomorphology 119 (1999), S. 63-71 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The Malpighian tubules of Drosophila hydei and D. melanogaster larvae are composed of two types of cell, principal cells and stellate cells. In the anterior larval Malpighian tubules approximately 26% (D. hydei) and 18% (D. melanogaster), respectively, of all cells are stellate cells. In the larvae of D. melanogaster, the stellate cells are fenestrated and the hemolymph space and tubule lumen are separated only by the basal lamina. Injection of dyes into the hemolymph did not indicate any facilitated transfer of substances through the fenestrated cells. The principal cells of the distal segment are carbonic anhydrase positive indicating transport activity, whereas the stellate cells lack this enzyme. In the stellate cells of the transitional segment, the sodium content is strikingly high in comparison to the neighbouring principal cells and lumen where no sodium was detected. This finding indicates that stellate cells reabsorb sodium as supposed earlier in 1969 by Berridge and Oschman (Tissue Cell 1:247–272).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004350050081
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    DNA conformation and dynamics (1999)
    Springer
    Radiation and environmental biophysics 38 (1999), S. 23-29 
    Details
    ISSN: 1432-2099
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract Nucleotide conformation and dynamics are important for the study of radiation damage to DNA at the atomic level. It is necessary to study not only normal oligonucleotide structure but also those containing modified bases which result from interaction with OH-radicals. There are now over 8000 atomic coordinate entries in the Brookhaven Protein Data Bank, of which over 900 relate to experimentally determined structures of nucleic acids and nucleic acid/protein complexes. We review some of these data which have led to the elucidation of novel DNA conformations, insight into DNA sequence specificity and knowledge of protein/DNA interactions. Further understanding of the conformation, stability and dynamics of nucleic acids has come from molecular modelling. We have used such techniques to study chemical modifications to bases such as alkylation of thymine and guanine and the effects of curvature in longer sequences. Recent improvements in this area include the inclusions of explicit counter-ions and solvent molecules, the use of Particle Mesh Ewald methods to incorporate the long-range electrostatic interactions and the use of longer time scale simulations. We have employed these methods to analyse the effects of incorporation of 8-oxodeoxyguanosine into duplex DNA. This lesion is a common result of radiation damage and is known to have important effects in mutagenesis, cancer and ageing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004110050134
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    3rd Annual Meeting of the German Society for Biological Radiation Research (Gesellschaft für Biologische Strahlenforschung) (1999)
    Springer
    Radiation and environmental biophysics 38 (1999), S. 72-72 
    Details
    ISSN: 1432-2099
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004110050139
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Formation of single- and double-strand breaks of pBR322 plasmid irradiated in the presence of scavengers (1999)
    Springer
    Radiation and environmental biophysics 38 (1999), S. 105-109 
    Details
    ISSN: 1432-2099
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract  By the method of gel electrophoresis, radiation-induced DNA single- and double-strand breaks (SSB, DSB) were studied with a model system of pBR322 solution in vitro in the presence of ·OH radical scavengers, mannitol and TE (10–2 mol dm–3 Tris and 10–3 mol dm–3 ethylene diamine tetra-acetic acid). Experiments showed that SSB resulted from one-hit events of radiation energy deposition and DSB resulted from both one-hit and two-hit energy deposition events and so were distinguished into two classes of αDSB and βDSB. Moreover, α/β, where α is the number of DSB per unit dose induced in one irradiation event and β the number of DSB per unit squared dose induced by the combination of two independent SSB, was related to the scavenging capacity, σ, and for σ〉108 s–1,αDSB predominate over DSB. On the other hand, if σ〈2×108 s–1, the measured G(αDSB) decreased in parallel with G(SSB), i.e., G(αDSB)/G(SSB) was a constant. When σ〉2×108 s–1, G(αDSB) decreased slightly so that the ratio of αDSB to SSB evidently increased. Therefore, αDSB could be induced by the radical transfer mechanism for σ〈2×108 s–1 and contrarily produced by the local multiply damaged sites (LMDS) mechanism for σ larger than this value. In addition, the distance for two independent complementary SSB forming a DSB was deduced, but no apparent variation of it was found in the wide σ range from ∼105 to ∼109 s–1, which shows that the DNA steric structure was not influenced by mannitol.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004110050145
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Repair of cellular radiation damage in space under microgravity conditions (1999)
    Springer
    Radiation and environmental biophysics 38 (1999), S. 133-138 
    Details
    ISSN: 1432-2099
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract  The influence of microgravity on the repair of x-ray-induced DNA double-strand breaks was studied in the temperature-conditional repair mutant rad54–3 of diploid yeast Saccharomyces cerevisiae. Cells were exposed on the ground and kept at a low temperature until microgravity conditions were achieved. In orbit, they were incubated at the permissive temperature to allow repair. Before re-entry they were again cooled down and kept at a low temperature until final analysis. The experiment, which was flown on the shuttle Atlantis on flight STS-76 (SMM-03), showed that repair of pre-formed DNA double-strand breaks in yeast is not impaired by microgravity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004110050149
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    The track structures of ionizing particles and their application to radiation biophysics (1999)
    Springer
    Radiation and environmental biophysics 38 (1999), S. 175-184 
    Details
    ISSN: 1432-2099
    Keywords: Key words Alpha particle ; Deuteron ; Proton ; Biophysical modeling ; Radiation quality influence ; Bacillus subtilis ; DNA density ; Monte Carlo calculations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract  A new approach to the interpretation of the effects of radiation on cells is described, in which sample particle tracks are constructed using a Monte Carlo computer program and the exposure of cellular targets to these tracks is simulated using a second program known as BIOPHYS. Data on the shapes and DNA contents of the cell nuclei are obtained from the literature. It is assumed that the sensitive material is DNA, and that the target is divided into cubes of approximately 2 nm (the diameter of the DNA helix) per side; the numbers of these cubes containing different numbers of ionizations are derived. Two different methods of analysing the output of BIOPHYS are described. In the first, it is assumed that lethality is caused by the occurrence of a number of ionizations equal to or greater than a certain threshold in one cube; in the second method, it is assumed that only two ionizations are required, in different parts of the cube, but that only some fraction of the cube is sensitive. These models have been applied to the interpretation of the variation of radiosensitivity with a linear energy transfer (LET) of spores of Bacillus subtilis exposed wet and dry, and good fits to the published experimental data were obtained using both models. Fits to experimental data for a range of other cell lines will be presented in a second paper.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004110050153
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Practical aspects of Monte Carlo simulation of charged particle transport: Mixed algorithms and variance reduction techniques (1999)
    Springer
    Radiation and environmental biophysics 38 (1999), S. 15-22 
    Details
    ISSN: 1432-2099
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract This paper is concerned with the practical implementation of Monte Carlo simulation methods for charged particle transport. The emphasis is on light particles (electrons and positrons) because of the larger scattering and energy straggling effects. Differential cross sections (DCS) for the various interaction mechanisms are described. As the average number of interactions along the particle track increases with the initial energy, detailed simulation becomes unfeasible at high energies. We can then rely on mixed simulation algorithms: hard events (i.e. individual interactions with angular deflection or energy loss larger than given cutoff values) are sampled from the DCS whereas soft events are simulated by means of a multiple scattering approach. Too frequently, the statistical uncertainty of analogue simulation (i.e. strict simulation of the physical interaction process) is found to be so large that results are meaningless. This problem can be partially solved by applying simple variance reduction techniques.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004110050133
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    Synthetic activity of rat blood lymphocytes under acute and continuous gamma-irradiation – fluorescent microspectral study (1999)
    Springer
    Radiation and environmental biophysics 38 (1999), S. 49-56 
    Details
    ISSN: 1432-2099
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract The effects of different doses of acute and continuous gamma-irradiation on the synthetic activity of rat blood lymphocytes stained with acridine orange were studied by fluorescent microspectrometry. Male rats were exposed to acute gamma-irradiation with doses of 7.5, 4 and 3 Gy, or to continuous irradiation with dose rates of 14.4, 2.1, 1.1 and 0.43 cGy/day, respectively. The changes of the synthetic activity of blood lymphocytes occurred in three main stages after acute gamma-irradiation and in four stages under continuous irradiation. The stages reflect the processes of depression and activation of the immune system under irradiation. Essential differences between the acute and continuous effects were observed in the first stage. After acute gamma-irradiation, the synthetic activity decreased sharply, indicating the predominant contribution of the damaging effect of irradiation, whereas under continuous irradiation, as a result of the stimulatory effect of low-dose irradiation, the synthetic activity increased during the first stage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004110050137
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Radon-induced lung cancer in smokers and non-smokers: risk implications using a two-mutation carcinogenesis model (1999)
    Springer
    Radiation and environmental biophysics 38 (1999), S. 57-71 
    Details
    ISSN: 1432-2099
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract Three sets of data (population statistics in non-smokers, data from an investigation of the smoking habits of British doctors and a study of Colorado uranium miners) were used to analyse lung cancer in humans as a function of exposure to radon and smoking. One of the aims was to derive implications for radon risk estimates. The data were analysed using a two-mutation radiation carcinogenesis model and a stepwise determination of the model parameters. The basic model parameters for lung cancer were derived from the age dependence fit of the spontaneous lung cancer incidence in non-smokers. The effect of smoking was described by two additional parameters and, subsequently, the effect of radon by three other parameters; these five parameters define the dependence of the two mutation steps on smoking and exposure to radon. Using this approach, a consistent fit and comprehensive description of the three sets of data have been achieved, and the parameters could, at least partly, be related to cellular radiobiological data. The model results explain the different effect of radon on non-smokers and smokers as seen in epidemiological data. Although the analysis was only applied to a limited number of populations, lung cancer incidence as a result of radon exposure is estimated to be about ten times higher for people exposed at the age of about 15 than at about 50, although this effect is masked (especially for smokers) by the high lung cancer incidence from smoking. Using the model to calculate the lung cancer risks from lifetime exposure to radon, as is the case for indoor radon, higher risks were estimated than previously derived from epidemiological studies of the miners' data. The excess absolute risk per unit exposure of radon is about 1.7 times higher for smokers of 30 cigarettes per day than for non-smokers, even though, as a result of the low spontaneous tumour incidence in the non-smokers, the excess relative risk per unit exposure for the smokers is about 20 times lower than for the non-smokers. This prediction could have serious consequences for the transfer of risk estimates between populations. Although the solution of the model presented here is not unique but dependent on the model assumptions, the predictions and risk implications are sufficiently supported to justify a thorough investigation of the applicability of the model to other radon data sets.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004110050138
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    A Monte Carlo code for positive ion track simulation (1999)
    Springer
    Radiation and environmental biophysics 38 (1999), S. 97-104 
    Details
    ISSN: 1432-2099
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract  An ion interaction model has been described for simulating positive ion tracks in a variety of media with the capability of interfacing with several secondary electron transport codes. Data are presented for single- and double-differential cross-sections, binding energies, probability density distribution for delocalisation parameters for conductors and tissue, branching ratios and ionisation efficiencies for water vapour and liquid water.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004110050144
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Biological effects of ion beams in Nicotiana tabacum L. (1999)
    Springer
    Radiation and environmental biophysics 38 (1999), S. 111-115 
    Details
    ISSN: 1432-2099
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract  The biological effects of ion beams on Nicotiana tabacum L., particularly the induction of chromosome aberrations, were investigated. Dry seeds were exposed to 12C5+, 4He2+ and 1H+ beams with linear energy transfer (LET) ranging from 1 to 111 keV/µm and irradiated with gamma-rays. Ion beams were more effective in reducing germination and survival of the seeds than gamma-rays. The LD50 for 12C5+ beams, 4He2+ beams and gamma-rays were 35, 60 and 500 Gy, respectively. The frequencies of mitotic cells with chromosome aberrations, such as chromosome bridges, acentric fragments and lagging chromosomes in the root tip cells of the exposed seeds, increased linearly with increasing doses. Relative biological effectiveness (RBE) values, based on the doses that induced a survival inhibition of 50% and a 10% frequency of aberrant cells, were 14.3–17.5 for the 12C5+ beams, 7.0–8.3 for the 4He2+ beams and 7.8 for the 1H+ beams. Furthermore, the relative ratios of the chromosome aberration types were significantly different between the ion beam and the gamma-ray regimes: chromosome fragments were more frequent in the former, and chromosome bridges in the latter. Based on these results, we concluded that the repair process of initial lesions induced by ion beams may be different from that induced by low- LET radiation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004110050146
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Condensed-history Monte-Carlo simulation for charged particles: what can it do for us? (1999)
    Springer
    Radiation and environmental biophysics 38 (1999), S. 163-173 
    Details
    ISSN: 1432-2099
    Keywords: Key words Charged particles ; Electron transport scheme ; Microdosimetry ; Monte Carlo simulation ; Radiation dosimetry ; Radiotherapy ; Track structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract  Condensed-history (CH) Monte-Carlo (MC) groups together the vast number of individual charged-particle collisions using multiple scattering theory for elastic angular changes and stopping power for energy losses. CH codes such as EGS4 have been enormously successful in simulating the transport of electrons, for example, in radiotherapy. MC-derived values of the water-to-air stopping-power ratio, s w/air, are used in all modern codes of practice for absolute dose determination in radiotherapy clinics. MC can also directly yield the dose ratio D med/D det for a dosimeter in a medium, and Correlated Sampling has been exploited to increase the efficiency, e. g., the central electrode in an ion chamber (aluminium vs. graphite). The extremely low density of the gas in an ion chamber poses problems for CH codes. However, multiple scattering can now be combined with single scattering and is expected to finally resolve important chamber perturbation effects. An exciting application of CH MC in radiotherapy is the computation of dose distributions in patients. Currently one can achieve an uncertainty around 1% (1 SD) in mm-sized voxels in several minutes for an electron beam and in around an hour for a photon treatment plan on hardware costing less than $20,000, and thus avoid all the various approximations conventionally used to account for inhomogeneities. In the microdosimetry/track structure field, CH codes have shown that the fluence (dΦ/dE) per unit dose at low electron energies is virtually independent of incident particle energy or depth, which simply explains the negligible RBE variation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004110050152
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Estimation of the target stem-cell population size in chronic myeloid leukemogenesis (1999)
    Springer
    Radiation and environmental biophysics 38 (1999), S. 201-206 
    Details
    ISSN: 1432-2099
    Keywords: Key words Cancer risk modelling ; Chronic myeloid leukemia (CML) incidence ; CML target stem cells ; genome translocation ; Low-dose exposure ; Radiation-induced CML
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract  Estimation of the number of hematopoietic stem cells capable of causing chronic myeloid leukemia (CML) is relevant to the development of biologically based risk models of radiation-induced CML. Through a comparison of the age structure of CML incidence data from the Surveillance, Epidemiology, and End Results (SEER) Program and the age structure of chromosomal translocations found in healthy subjects, the number of CML target stem cells is estimated for individuals above 20 years of age. The estimation involves three steps. First, CML incidence among adults is fit to an exponentially increasing function of age. Next, assuming a relatively short waiting time distribution between BCR-ABL induction and the appearance of CML, an exponential age function with rate constants fixed to the values found for CML is fitted to the translocation data. Finally, assuming that translocations are equally likely to occur between any two points in the genome, the parameter estimates found in the first two steps are used to estimate the number of target stem cells for CML. The population-averaged estimates of this number are found to be 1.86×108 for men and 1.21×108 for women; the 95% confidence intervals of these estimates are (1.34×108, 2.50×108) and (0.84×108, 1.83×108), respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004110050156
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Announcement (1999)
    Springer
    Radiation and environmental biophysics 38 (1999), S. 219-219 
    Details
    ISSN: 1432-2099
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004110050161
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Tumor therapy and track structure (1999)
    Springer
    Radiation and environmental biophysics 38 (1999), S. 229-237 
    Details
    ISSN: 1432-2099
    Keywords: Key words Ions ; Tumor therapy ; RBE ; Track structure ; Treatment planning ; Carbon beam
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract  The elevated relative biological effectiveness (RBE) of heavy ions like carbon is the main reason for their use in radiotherapy and is due to the microscopic distribution of dose inside each particle track. High local doses produce lesions that are expected to have a diminished possibility of repair. Thus, RBE depends on track structure and on the biological repair capacity of the tissue that is affected by the irradiation. For tumor treatment planning with heavy ions, the beam quality and the tissue sensitivity have to be taken into account. Using the dependence of radial dose distribution on particle energy and atomic number on the physical side and x-ray dose response for the repair capacity on the biological side, the response to particle irradiation can be calculated in the local effect model (LEM) and used for treatment planning. This article traces the route from electron emission as the basis of track structure to the RBE calculation and the application in treatment planning.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004110050163
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Effect of lithium on thyroidal 131iodine uptake, its clearance, and circulating levels of triiodothyronine and thyroxine in lead-treated rats (1999)
    Springer
    Radiation and environmental biophysics 38 (1999), S. 261-266 
    Details
    ISSN: 1432-2099
    Keywords: Key words Iodine uptake ; Lead ; Lithium ; Rats ; Thyroid ; Thyroid hormones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract  The influence of lead acetate (50 mg per kg body weight) on the 131iodine (131I) biokinetics (uptake and retention) in rat thyroid and serum levels of triiodothyronine (T3) as well as thyroxine (T4) was evaluated as a function of time and in combination with lithium treatment. The 2-h and 24-h uptake of 131I in the thyroid was stimulated significantly by lead treatment. The 24-h uptake showed a maximum stimulation after 4 months of lead treatment. Lithium supplementation, however, showed the opposite effect by reducing the iodine uptake, whereby the maximum decrease was noticed after 2 months of treatment. Further, simultaneous lead and lithium treatment resulted in an even more pronounced increase of 2-h 131I uptake with a maximum after 3 months. However, the 24-h uptake after 3 months and 4 months of treatment did not differ significantly from the lead treated reference groups. The thyroidal biological half-life of 131I (Tbiol) was found to have clearly increased following the lead/lithium treatment. Interestingly, the combined lead/lithium treatment applied for 4 months caused a further growth of Tbiol, thus reflecting an increased retention of 131I. A maximum increase of Tbiol was seen after 2 months of combined treatment. A progressive decline of the circulating T3 and T4 levels following lead or lithium treatment was noticed and was more pronounced after combined treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004110050166
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Mitochondrial gene expression in developing male gametophytes of male-fertile and S male-sterile maize (1999)
    Springer
    Sexual plant reproduction 11 (1999), S. 323-330 
    Details
    ISSN: 1432-2145
    Keywords: Key words Cytoplasmic male sterility ; Pollen development ; Zea mays ; mitochondria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Mitochondria play a critical role in the normal development of the plant male gametophyte and in the disruption of normal gametophyte development associated with cytoplasmically inherited male sterility (CMS). To investigate the role of mitochondria in these processes, the accumulation of mitochondrial gene transcripts and the accumulation of nuclear gene transcripts encoding mitochondrial proteins were investigated through male gametophyte development in normal maize and through the course of pollen abortion in CMS-S maize. Male gametophytes differing in developmental stage were isolated from male-fertile or male-sterile plants by sucrose density gradient centrifugation. Mature pollen was collected from dehiscent anthers of male-fertile plants. Aborted pollen, which collapsed during starch accumulation, was isolated from emergent tassels of CMS-S male-sterile plants. Microspores, developing pollen and mature pollen exhibited striking differences in mitochondrial transcript accumulation. Mature pollen lacked detectable mitochondrial transcripts. Aborted pollen of CMS-S plants contained abundant, intact transcripts of all mitochondrial genes studied, but prematurely degraded transcripts of several nuclear genes. Transcripts of the CMS-S associated mitochondrial open reading frames (orf355 and orf77) were detected from the early stages of microspore development through the aborted pollen stage. The implications of these findings are discussed in terms of the mitochondrial requirements for pollen function and the mechanism of pollen abortion in CMS-S maize.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050159
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Effect of pollen source and pollen ploidy on endosperm formation and seed set in pseudogamous apomictic Paspalum notatum (1999)
    Springer
    Sexual plant reproduction 11 (1999), S. 331-335 
    Details
    ISSN: 1432-2145
    Keywords: Key words Apomixis ; Pseudogamy ; Endosperm ; Endosperm balance number
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  It is generally accepted that most angiosperms require an accurate balance between maternal and paternal genome contribution for endosperm development. The endosperm balance number (EBN) hypothesis postulates that each species has an effective number which must be in a 2:1 maternal to paternal ratio for normal endosperm development and seed formation. The aim of this work was to investigate the effect of different sources and ploidy levels of pollen donors on endosperm formation and seed production of aposporous tetraploid (2n=4×=40) Paspalum notatum. Hand-emasculated spikelets of an apomictic 4× plant were dusted with pollen of 2×, 4×, 5×, 6× and 8× races of the same species; 3× and 4× races of a phylogenetically closely related species, P. cromyorrhizon; and 2× and 4× races of P. simplex, a species of a different subgenus. Experiments including self-pollination as well as emasculation without pollination were conducted for controls. Results indicated that apomictic 4×P. notatum is a pseudogamous species with effective fertilization of the two unreduced (2n) polar nuclei by a reduced (n) sperm. Endosperm development and seed production occurred independently of the species or the ploidy level of the pollen donor. However, seed germination rates were significantly lower than in the self-pollinated control when the pollen donor was 3×P. cromyorrhizon or 2× and 4×P. simplex. Aposporous embryo sacs in Paspalum contribute to endosperm formation with two unreduced (2n) polar nuclei, while the male contribution is the same as in sexual plants (n). Since sexual Paspalum plants fit the EBN hypothesis, the EBN insensitivity observed in apomictic plants might be a prerequisite for the spread of pseudogamous apomixis. The EBN insensitivity could have arisen as an imprinting consequence of a high maternal genome contribution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050160
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Characterization of an anther-expressed protein kinase gene in the potato Solanum berthaultii and its antisense inhibition in transgenic plants (1999)
    Springer
    Sexual plant reproduction 11 (1999), S. 336-346 
    Details
    ISSN: 1432-2145
    Keywords: Key words Pollen germination ; cDNA library ; Solanum berthaultii ; Protein kinase ; Antisense inhibition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  A cDNA clone (1.7 kb) isolated from a cDNA library of in-vitro germinated pollen from the potato species Solanum berthaultii contains an open reading frame of 465 amino acid residues. The predicted protein sequence has typical sequence characteristics of the catalytic subunit of the cyclic-nucleotide dependent protein kinases isolated from yeasts and animals, and the gene has been provisionally termed SBPK, (Solanum berthaultii protein kinase) A transcript of about 1.9 kb was detected on a northern blot in developing anthers, mature pollen, and in-vitro germinated pollen, but not in other plant tissues. The expression in anthers corresponds to the late uninucleate stage of microspore development. Isolation and nucleotide sequencing of a SBPK genomic clone revealed the kinase transcribed region to be interrupted by two introns, both close to the 5′end of the open reading frame, one upstream and one downstream of the start codon. Chimeric genes were constructed by fusing the coding sequence in the antisense orientation to the promoter of a strong late-expressed pollen gene, LAT52, and introduced in potato. Transformants fell into two classes, one displaying a typical antisense phenotype, and a second type arising from a cosuppression event. Both types of transformant gave rise to increased proportions of defective pollen, although the cosuppression effect was more severe. The results indicate that this anther-expressed protein kinase is essential for pollen development in potato.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050161
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Sexual reproduction in the cork oak (Quercus suber L.). I. The progamic phase (1999)
    Springer
    Sexual plant reproduction 11 (1999), S. 347-353 
    Details
    ISSN: 1432-2145
    Keywords: Key words Quercussuber ; Cork oak ; Pollen tube arrest ; Pollen tube competition ; Ovule abortion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Cork oak (Quercus suber L.) is a monoecious wind-pollinated species with a protandrous system to ensure cross-pollination. To the best of our knowledge, this report provides the first insight into the sexual reproduction cycle in this species. The cork oak flowering season extends from April until the end of May. Our results show that, at anthesis, the pistillate flower is not completely formed and ovules are just starting to develop. Pollen reaching the dry stigmatic surface adheres to the receptive cells, germinates and penetrates the epidermis in aproximately 24 h, and grows through the intercellular spaces of a solid transmitting tissue. In cross-pollination, a sequential arrest of pollen tubes was observed along the style, providing preliminary evidence for a pollen tube competition mechanism. As a consequence, few pollen tubes reach the basal portion of the style. Furthermore, pollen tube growth is a discontinuous process since tubes are arrested in the basal portion of the style about 10–12 days after pollination. While tubes are latent, the ovarian loculus starts to develop from an emerging mass of sporogeneous cells which later will differentiate into the placenta and ovules. One and a half months after pollination ovules complete their differentiation, tubes resume growth and fertilisation occurs. Ovular abortion is frequent at this stage, and only one ovule will successfully mature during autumn into a monospermic seed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050162
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Post-zygotic gametic selection due to endosperm balance number explains unusual chromosome numbers of 3×× 2× progeny in Solanum (1999)
    Springer
    Sexual plant reproduction 12 (1999), S. 27-31 
    Details
    ISSN: 1432-2145
    Keywords: Key words Endosperm breakdown ; Aneuploidy ; 3×× 2× crosses ; Solanum commersonii ; Solanum tuberosum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Crosses between triploid and diploid genotypes are usually the best sources of trisomics in potato as well as in several other crop species. However, 3×× 2× crosses between triploid (2n=3×=36; 2EBN) Solanum commersonii-S. tuberosum hybrids and diploid (2n= 2×=24; 2EBN) genotypes gave progenies with a high number of extra chromosomes, 29–36, suggesting that only eggs with 17–24 chromosomes produced embryos that reached full development. Our hypothesis is that although triploids produce eggs with a range of chromosome numbers, 3×× 2× crosses involving a 2×(2EBN) parent favor eggs with a high chromosome number. These eggs have higher probabilities of possessing the same endosperm balance number (EBN) value (i.e. 1) of gametes produced by the 2EBN diploid parent to give the required 2:1 maternal to paternal EBN ratio in the hybrid endosperm. Under this model, trisomics are produced only if the diploid parent has an EBN of 1. Based on our results and those reported in the literature, it is proposed that in 3×(2EBN) × 2×(2EBN) crosses the endosperm balance number exercises negative selection for gametes with a low chromosome number, and a corresponding low EBN, and positive selection for gametes with a high chromosome number and EBN.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050168
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Use of the APETALA1 promoter to assay the in vivo function of chimeric MADS box genes (1999)
    Springer
    Sexual plant reproduction 12 (1999), S. 14-26 
    Details
    ISSN: 1432-2145
    Keywords: Key words Arabidopsis ; Flower development ; MADS domain ; Functional specificity ; Domain swapping
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The MADS domain proteins AP1, AP3, PI, and AG are required to specify the four classes of organs in an Arabidopsis flower. Each of these proteins is involved in specifying the identity of two different organs in two adjacent floral whorls. They all share a 56-amino acid MADS domain required for DNA binding and dimerization, a region (I or L) involved in dimerization specificity, the K domain named for its sequence similarity to the coiled-coil of keratin, and a variable carboxy terminal sequence. The abilities of these four related proteins to specify distinct organs presumably result from differential effects on transcriptional regulation. We have previously used chimeric MADS box genes, expressed under the constitutive 35S promoter, to map the regions of these proteins that are responsible for their different organ identity activities. In this paper, we extend these studies by characterizing the phenotypes of plants ectopically expressing chimeric genes under the control of the endogenous AP1 promoter. Similar results are obtained with the 35S and AP1 promoters, although the endogenous promoter does provide a more rigorous test of function. We also describe results from new chimeric gene constructs that show new in vivo functions for the K domain and the amino-terminal portion of the MADS domain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050167
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Rethinking cytoskeleton in plant reproduction: toward a biotechnological future? (1999)
    Springer
    Sexual plant reproduction 12 (1999), S. 67-70 
    Details
    ISSN: 1432-2145
    Keywords: Key words Cytoskeleton ; Cytoskeleton proteins ; Cytoskeleton function ; Pollen tube ; Embryo sac
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Sexual reproduction in plants is intimately connected to the activity of the cytoskeletal apparatus in reproductive cells. Because of the ease with which the pollen tube can be studied, it has become a model for studying many aspects of cell physiology related to the cytoskeleton, such as movement of organelles and vesicles and cell division. However, information about cytoskeletal proteins is still insufficient for determining cytoskeletal functions during reproduction, especially in terms of cell-cell interactions. One reason may be that cytological and biochemical research on the cytoskeleton of pollen and the embryo sac has not been complemented by sufficient research activity at genetic and molecular levels, and few laboratories are currently involved in this work. This might be because of problems in identifying appropriate applied applications of the work that might attract more investigation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050173
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Apomixis and sexuality in diploid and tetraploid accessions of Brachiaria decumbens (1999)
    Springer
    Sexual plant reproduction 12 (1999), S. 43-52 
    Details
    ISSN: 1432-2145
    Keywords: Key words Apomixis ; Sexuality ; Day length ; Embryology ; Brachiaria ; Agamic complexes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Meiotic and aposporous embryo sacs and the initial steps of parthenogenetic embryogenesis and endosperm formation were investigated in diploid and tetraploid accessions of Brachiaria decumbens in two environments, differing mainly in day length: early summer and late autumn. Both diploid and tetraploid accessions were facultative apomicts. Di(ha)ploids showed a much lower level of apomixis (10% to15%) than tetraploids (80% to 95%). No obligate sexual diploids were found; thus, their occurrence in natural populations is obscure. It is suggested that reproduction in B. decumbens, as in other agamic complexes of the Paniceae tribe, in general, approximates a diploid-tetraploid-(di)haploid reproductive cycle which does not involve triploids. The dihaploids were fertile and survived in nature. Development of the reproductive structures depended on the environment. In autumn, in contrast to early summer, many meiotic and aposporous embryo sacs degenerated during development, leading to a significant reduction in the proportion of parthenogenetic embryos. Whether this effect can be attributed to day length or simply to age remains to be investigated. The ratio of aposporous to sexual embryo sacs was relatively stable over the two seasons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050170
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Mitochondrial orf107 transcription, editing, and nucleolytic cleavage conferred by the gene Rf3 are expressed in sorghum pollen (1999)
    Springer
    Sexual plant reproduction 12 (1999), S. 53-59 
    Details
    ISSN: 1432-2145
    Keywords: Key words Cytoplasmic male sterility ; Mitochondria ; Sorghum ; RNA editing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Restoration of male fertility in the A3, IS1112C source of cytoplasmic male sterility (cms) in sorghum is exacted in a gametophytic manner. One required nuclear gene, Rf3, regulates a nucleolytic transcript processing activity, cleaving sequences internal to the chimeric mitochondrial open reading frame orf107. We examined mitochondrial transcription, RNA editing, and action of Rf3 in developing pollen from a male-sterile line, the progenitor, a male-fertile line, and the fertile F1 to determine if these expression processes were manifested at the haploid pollen stage. Steady-state levels of orf107 transcripts and nucleolytic processing conferred by Rf3 were similar to observations from leaves, indicating comparable expression in pollen. RNA editing frequency at two of three sites in orf107 was differentially suppressed compared to leaves, but editing was higher in male-sterile plants than in fertile plants, consistent with the possibility that nucleolytic cleavage is enhanced by editing. The differential suppression of editing frequency at two sites in orf107 contrasts with near-complete editing of a third site in orf107, shared with atp9, indicating that factors influencing editing frequency of the chimeric transcript are temporally regulated and sequence-specific. Since action of the nuclear gene Rf3 is manifested at the diploid and haploid stages, pollen-specific expression of this fertility restoration gene is not required in the A3 gametophytic cms system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050171
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Pollen-expressed S-RNases are not involved in self-incompatibility in Lycopersicon peruvianum (1999)
    Springer
    Sexual plant reproduction 12 (1999), S. 76-87 
    Details
    ISSN: 1432-2145
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Self-incompatibility in solanaceous plants is gametophytically controlled by a multiallelic S-locus. The only known S-locus product is a series of extracellular ribonucleases (the S-RNases) which are expressed in the mature style and determine its self-incompatibility phenotype. Potentially, S-RNases also determine the self-incompatibility phenotype of pollen as some solanaceous plants express this protein for a brief period during anther development. To test this, we first showed that the S3-RNase of Lycopersicon peruvianum is expressed during anther development. We then transformed L. peruvianum plants with sense and antisense versions of the S3-RNase coding region under the control of a pollen-specific promoter. Pollen from the transgenic plants accumulated S3-RNase transcripts and the S3-RNase protein was detected immunologically in the sense transgenic plants. However, neither the sense nor the antisense S3-RNase constructs altered the self-incompatibility phenotype of pollen from the transgenic plants, demonstrating the S3-RNase is not the pollen product of the S3-allele.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050175
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Comparison of an S-protein expression between self-compatible and -incompatible Japanese pear cultivars (1999)
    Springer
    Sexual plant reproduction 12 (1999), S. 88-93 
    Details
    ISSN: 1432-2145
    Keywords: Key words Japanese pear ; Pyrus serotina ; S-allele ; Self-incompatibility ; S-protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  An S4-allele-associated protein (S4-protein) was identified by both isoelectricfocusing (IEF) polyacrylamide-gel electrophoresis and N-terminal amino-acid sequences in self-incompatible Nijisseiki (self-in- compatibility genotype=S2S4) and self-compatible Osa-Nijisseiki (S2S4 SM, SM=stylar-part mutant) styles of the Japanese pear, Pyrus serotina Rehd. var. culta Rehd. Expression of the protein in the cultivars was compared during flower bud development and at post-transcriptional levels. In mature styles, S4-protein could be detected on IEF gel in both cultivars and the N-terminal amino acid sequences were identical, although Osa-Nijisseiki contained only one-third the amount contained in Nijisseiki. No difference was observed in S2-protien amounts. In Nijisseiki styles, S4-protein was already detectable 8 days before anthesis (DBA) and it was synthesized consistently until 2 days after anthesis (DAA); the amount increased 4.7-fold during these 10 days. In contrast, S4-protein in Osa-Nijisseiki was not detected earlier than 6 DBA; a small amount was found at 4 DBA, and it increased gradually as flowers developed. Thus, expression of Osa-Nijisseiki S4-protein is developmentally controlled in the same way as that of Nijisseiki S4-protein, but with a time lag of several days; the protein level at 2 DAA corresponded to that of Nijisseiki earlier than 4 DBA. S4-proteins from both Nijisseiki and Osa- Nijisseiki showed RNase activity and the activity was also developmentally controlled; it increased about fourfold during the interval from 8 DBA to 2 DAA in Nijisseiki, and 3.3-fold during the interval from 4 DBA to 2 DAA in Osa-Nijisseiki. Activity at 2 DAA, however, was twice as high in Nijisseiki. In vitro protein synthesis showed that poly(A)+ from mature Osa-Nijisseiki styles could form S4-like protein in a manner similar to that of Nijisseiki. These results suggest that the self-compatibility of Osa-Nijisseiki is due to a low level of S4-protein expression, a mechanism very similar to the low level of S-protein and weak incompatibility in immature styles of self-incompatible Nijisseiki. Part of this protein repression may be regulated during post-transcriptional events.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050176
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Megasporogenesis in Arabidopsis thaliana L.: an ultrastructural study (1999)
    Springer
    Sexual plant reproduction 12 (1999), S. 99-109 
    Details
    ISSN: 1432-2145
    Keywords: Key words Arabidopsis thaliana ; Megasporogenesis ; Meiosis ; Ultrastructure ; Cellular polarity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  In this study, megasporogenesis of the plant model Arabidopsis thaliana was investigated by electron microscopy for the first time. The data described here could constitute a reference for future investigations of Arabidopsis mutants. During the beginning of meiosis the megaspore mother cell shows a polarity created by unequal distribution of organelles in the cytoplasm. Plastids accumulate in the chalazal region and long parallel saccules of endoplasmic reticulum, small vacuoles and some dictyosomes are found in the micropylar region. Plasmodesmata are abundant in the chalazal cell wall. The nucleus is almost centrally localized and contains a prominent excentric nucleolus and numerous typical synaptonemal complexes. After the second division of meiosis the four megaspores are separated by thin cell walls crossed by numerous plasmodesmata and do not show significant cellular organization. The young functional megaspore is characterized by a large nucleus and a large granular nucleolus. The cytoplasm is very electron dense due to the abundance of free ribosomes and contains the following randomly distributed organelles: mitochondria, a few short saccules of endoplasmic reticulum, dictyosomes and undifferentiated plastids. However, there is no apparent polarity, except for the distribution of some small vacuoles which are more abundant in the micropylar region of the cell. The degenerating megaspores are extremely electron dense and do not show any substructure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050178
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Promoter region of Ory s 1, the major rice pollen allergen gene (1999)
    Springer
    Sexual plant reproduction 12 (1999), S. 125-126 
    Details
    ISSN: 1432-2145
    Keywords: Key words Gene regulation ; Ory s 1 ; Oryza sativa ; Pollen allergen ; Promoter ; Rice
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050182
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Successful first and second backcrosses of S. nigrum (+) S. tuberosum somatic hybrids with both Solanum parents (1999)
    Springer
    Sexual plant reproduction 12 (1999), S. 144-151 
    Details
    ISSN: 1432-2145
    Keywords: Key words Solanum tuberosum ; Solanum nigrum ; Somatic hybrids ; Backcross experiments ; Phytophthora infestans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Somatic hybrids of Solanum nigrum (+) 2× potato were successfully crossed with S. nigrum and with potato. First and second backcross progeny with S. nigrum could easily be obtained. One of the BC1 genotypes was already self-fertile. Backcrosses with potato had a much lower success rate. Only pollinations with tetraploid potato resulted in seed-containing berries. Two BC1 genotypes were obtained after 4362 pollinations from which 505 ovules were cultured. The first BC1 genotype grew vigorously in vitro and in the greenhouse and flowered abundantly. The second BC1 showed many abnormalities and dropped its flowers before anthesis. The first BC1 was again crossed with tetraploid potato and in this generation also the success rate was low. Over 5000 pollinations resulted in 1750 berries from which over 3000 ovules were obtained. Twelve plants germinated from these ovules and they were not as vigorous in vitro and in vivo as the BC1 parent. Some of the BC2 genotypes were used for further backcrosses but no BC3 plants were obtained. BC1 and BC2 genotypes that resulted from the backcross program with potato were tested for resistance to Phytophthora infestans. The BC1 genotype was as resistant as the S. nigrum fusion parent, but among the eight BC2 genotypes scored six were resistant, whereas two genotypes showing lesions were susceptible.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050185
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Isolation and osmotic relations of developing megagametophytes of Torenia fournieri (1999)
    Springer
    Sexual plant reproduction 12 (1999), S. 152-157 
    Details
    ISSN: 1432-2145
    Keywords: Keywords Megagametophyte ; Embryo sac ; Osmotic potential ; Protoplast ; Torenia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  A new method is reported to isolate and handle living megagametophytes of Torenia fournieri at any developmental stage. The stages were determined using light microscopy and delimited by correlating floral morphological traits. When significant changes in the osmotic pressure were found during development, enzyme solutions contained different concentrations of osmoticum. Osmotic pressure is lowest in the megaspore, increases until the four-nucleate stage and then gradually decreases until complete embryo sac formation. In enzymatic solutions containing appropriate concentrations of osmoticum, protoplasts of megaspores, two-, four-, eight-nucleate embryo sacs, egg cells, synergids and central cells were successfully isolated. The living protoplasts were collected by micromanipulator, transferred into microdroplets and tested for viability.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050186
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Gametic behavior in a marine green alga, Monostroma angicava: an effect of phototaxis on mating efficiency (1999)
    Springer
    Sexual plant reproduction 12 (1999), S. 158-163 
    Details
    ISSN: 1432-2145
    Keywords: Key words  Evolution of anisogamy ; Mating behavior ; Mating efficiency ; Monostroma angicava ; Phototaxis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract. The role of phototactic behavior of gametes was tested experimentally in the slightly anisogamous marine green alga Monostroma angicava Kjellman, and the effect of phototaxis on mating efficiency was discovered. Both male and female gametes showed positive phototaxis in response to a white light source. In contrast, they did not respond to a red light source. Their swimming velocity did not differ between these two illuminating light sources. It was, therefore, suggested that the search ability of the gamete itself might not vary between phototactic and non-phototactic conditions. The number of zygotes formed during the mating process may be expressed as the product of the number of encounters between male and female gametes and the fraction of encounters that result in sexual fusion. In this study, with high densities of male and female gametes mixed in test tubes, almost all minor (fewer in number) gametes fused sexually within 10 min. After dilution of the gamete suspensions by half, mating efficiency in test tubes illuminated by white light from above was higher than that in dark controls. This suggests that male and female gametes gathered at the water surface through their positive phototaxis, thus increasing the rate of encounters. Mating efficiency also decreased if the test tubes were illuminated from above by white light and also shaken. Since negative phototaxis is clearly shown in planozygotes, we suggest that positive phototaxis of male and female gametes in M. angicava is an adaptive trait for increasing the rate of gametic encounters rather than for the dispersal of zygotes as previously reported for zoospores of some marine algae.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050187
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Pollen sporopollenin: degradation and structural elucidation (1999)
    Springer
    Sexual plant reproduction 12 (1999), S. 171-178 
    Details
    ISSN: 1432-2145
    Keywords: Key words Pollen ; Exine ; Sporopollenin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  We report the isolation of purified sporopollenin from pollen grains of different species and its complete solubilization. Exine from Pinus pinaster, Betula alba, Ambrosia elatior and Capsicum annuum was extracted by treatment with hydrogen fluoride in pyridine. These exines were purified from their aromatic moieties and from fatty acids linked by ester bonds using acidolysis and saponification treatments. The biopolymer obtained retains almost completely the shape of the original pollen grain. Fourier-transform infrared spectroscopy analysis of the isolated sporopollenin showed the absence of polysaccharide and phenolic material and the presence of carboxylic acid groups joined to unsaturations and ether linkages. Sporopollenin samples were successfully degraded by exhaustive 24-h ozonolysis at room temperature. Gentle ozonolysis (3 h at 0°C) did not completely degrade the biopolymer. The compounds obtained after exhaustive ozonolysis were analysed by gas chromatography-mass spectrometry. Dicarboxylic acids with a low number of carbon atoms were identified as major components of sporopollenin from P. pinaster, A. elatior and C. annuum, representing 28.8%, 63.2% and 88.5%, respectively, of the total compounds obtained. Fatty acids and n-alkanes also were identified in P. pinaster, A. elatior and B. alba sporopollenin. From the data obtained, an hypothesis about the chemical nature and structural arrangement of the sporopollenin is proposed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050189
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Effects of microtopography on mycorrhizal infection in Atlantic white cedar (Chamaecyparis thyoides (L.) Mills.) (1999)
    Springer
    Mycorrhiza 8 (1999), S. 175-180 
    Details
    ISSN: 1432-1890
    Keywords: Key words Vesicular arbuscular mycorrhizae ; Chamaecyparis thyoides ; Cupressaceae ; Wetlands ; Swamp ; Microsites ; Hummocks ; Anoxia ; Restoration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The presence and intensity of mycorrhizal infection in wetland trees has received relatively little attention. We report here a study of mycorrhizal infection in Atlantic white cedar (Chamaecyparis thyoides), a member of the Cupressaceae, which forms monospecific stands in swamps throughout the Atlantic Coastal Plain of North America. The trees grow on the tops of elevated hummocks, but the fine roots extend along the sides of the hummocks to the flooded hollows. Roots from all microtopographic positions on the hummocks are colonized by vesicular-arbuscular mycorrhizae (VAM). In addition to arbuscules and vesicles, occasional hyphal coils are observed within the cortex cells. However, frequencies of occurrence of vesicles and arbuscles are significantly higher on the tops and sides than at the bottoms of the hummocks. These differences correspond to higher concentrations of acetylglucosamine in the roots at these positions. Frequencies of all mycorrhizal structures (arbuscles, vesicles and hyphae) in roots at the base of the hummocks are very low. These results suggest that mycorrhizal colonization in wetland trees is greater in aerobic microsites, a finding in accord with results from studies of both herbaceous wetland plants and other wetland trees.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050231
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Utilisation of organic nitrogen and phosphorus sources by mycorrhizal endophytes of Woollsia pungens (Cav.) F. Muell. (Epacridaceae) (1999)
    Springer
    Mycorrhiza 8 (1999), S. 181-187 
    Details
    ISSN: 1432-1890
    Keywords: Key words Ericaceae ; Hymenoscyphus ericae ; Ericoid mycorrhiza ; Plant nutrition ; Ascomycetes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The ability of four ericoid mycorrhizal endophytes isolated from roots of Woollsia pungens (Cav.) F. Muell. (Epacridaceae) to utilise organic forms of nitrogen and phosphorus during growth in axenic culture was assessed. All isolates were able to utilise glutamine, arginine and bovine serum albumin (BSA), along with NH4 + or NO3 –, in most cases yielding at least as much biomass as the ericoid mycorrhizal endophyte Hymenoscyphus ericae (Read) Korf & Kernan. All isolated endophytes were able to utilise BSA, arginine and glutamine as sole sources of N and C. With the exception of a single isolate (C40), which showed little growth on glutamine, biomass yields on glutamine as the sole N and C source was significantly greater for all isolates than on either of the other two organic N sources. Two isolates from W. pungens (C40 and A43) utilised DNA and sodium inositol hexaphosphate as sole P sources, in each case yielding significantly more biomass than H. ericae. The results suggest that mycorrhizal endophytes from epacrid plant hosts and those from ericaceous hosts have similar abilities to utilise organic forms of N and P.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050232
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Comparison of two test systems for measuring plant phosphorus uptake via arbuscular mycorrhizal fungi (1999)
    Springer
    Mycorrhiza 8 (1999), S. 207-213 
    Details
    ISSN: 1432-1890
    Keywords: Key words Arbuscular mycorrhizal fungi ; Hyphal phosphorus uptake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Plant phosphorus uptake via external hyphae of arbuscular mycorrhizal fungi has been measured using compartmented systems where a hyphal compartment is separated from a rooting compartment by a fine mesh. By labelling the soil within the hyphal compartment with a radioactive phosphorus (P) isotope, hyphal uptake of P into the plant can be traced. The objective of this growth chamber study was to test two hyphal compartments of different design with respect to their suitabilities for measurement of hyphal P uptake. One hyphal compartment was simply a nylon mesh bag filled with 32P-labelled soil. The labelled soil in the other hyphal compartment was completely surrounded by an 8–10 mm layer of unlabelled soil that served as a buffer zone. Mycorrhizal and non-mycorrhizal subterranean clover plants were grown in pots with a centrally positioned hyphal compartment. Uptake of radioactive P by non-mycorrhizal control plants was 25% of that by mycorrhizal plants with the mesh bag but only 3% when including the buffer zone. Based on this good control of non-mycorrhizal P uptake from within the hyphal compartment and its greater ease of handling once produced, we judged the hyphal compartment including a buffer zone to be superior to the mesh bag.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050236
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Coinoculation of containerized Douglas-fir (Pseudotsuga menziesii) and maritime pine (Pinus pinaster) seedlings with the ectomycorrhizal fungi Laccaria bicolor and Rhizopogon spp. (1999)
    Springer
    Mycorrhiza 8 (1999), S. 189-195 
    Details
    ISSN: 1432-1890
    Keywords: Key words Coinoculation ; Fungal colonization ; Mixed inoculum ; Alginate inoculum ; Reforestation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Coinoculations with mycelium of Laccaria bicolor and spores of Rhizopogon spp. included in alginate gel have been carried out to determine: (1) the ability of the mixed inoculum to produce dual-colonized containerized Douglas-fir and maritime pine planting stocks and (2) the colonization pattern of the two fungi in individual root systems. For both tree species, the maximal proportion of dual-colonized seedlings obtained almost never exceeded 50%. The rest of the seedlings remained colonized by a single fungus or were non-colonized. In Douglas-fir inoculations, the relationship between the dual-colonized seedlings obtained and the initial dose of the two fungi was highly significant. The highest proportion of dual-colonized seedlings was obtained when the highest dose of R. subareolatus was used (106 spores/seedling), regardless of the dose of L. bicolor. Among the treatments producing 25% or more dual-colonized seedlings, differences in the proportion of Laccaria/Rhizopogon mycorrhizas and total root colonization percentages were not clearly related to the initial combination of doses. The proportion of dual-colonized maritime pine seedlings was not significantly related to the initial inoculation doses of the two fungi. The proportion of Laccaria/Rhizopogon mycorrhizas was not significantly different among treatments with 25% or more dual-colonized seedlings, whereas total colonization percentages ranged from 37% with the combination 0.08/104 (g L. bicolor / spores R. roseolus per seedling) to 74% with the combination 0.08/106, this difference being statistically significant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050233
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Visualization of ribosomal DNA loci in spore interphasic nuclei of glomalean fungi by fluorescence in situ hybridization (1999)
    Springer
    Mycorrhiza 8 (1999), S. 203-206 
    Details
    ISSN: 1432-1890
    Keywords: Key words Arbuscular mycorrhiza ; Spore nuclei ; Fluorescence in situ hybridization ; Ribosomal DNA loci
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Fluorescence in situ hybridization (FISH) was applied to interphasic nuclei isolated from spores of four species of AM fungi : Scutellospora castanea, Glomus mosseae, Glomus intraradices and Gigaspora rosea. Ribosomal DNA loci were visualized using digoxigenin-labeled 25 S rDNA probes obtained by nested PCR. Several hybridization sites were detected per nucleus and an internuclear variability was observed in the number of loci. This is the first report of successful application of FISH to analyse the genomes of glomalean fungi.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050235
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Relationships between fungal uptake of ammonium, fungal growth and nitrogen availability in ectomycorrhizal Pinus sylvestris seedlings (1999)
    Springer
    Mycorrhiza 8 (1999), S. 215-223 
    Details
    ISSN: 1432-1890
    Keywords: Key words Ammonium ; Ergosterol ; Extramatrical mycelium ; Paxillus ; Suillus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Nitrogen deposition and intentional forest fertilisation with nitrogen are known to affect the species composition of ectomycorrhizal fungal communities. To learn more about the mechanisms responsible for these effects, the relations between fungal growth, nitrogen uptake and nitrogen availability were studied in ectomycorrhizal fungi in axenic cultures and in symbiosis with pine seedlings. Effects of different levels of inorganic nitrogen (NH4) on the mycelial growth of four isolates of Paxillus involutus and two isolates of Suillus bovinus were assessed. With pine seedlings, fungal uptake of 15N-labelled NH4 was studied in short-term incubation experiments (72 h) in microcosms and in long-term incubation experiments (3 months) in pot cultures. For P. involutus growing in symbiosis with pine seedlings, isolates with higher NH4 uptake were affected more negatively at high levels of nitrogen availability than isolates with lower uptake. More NH4 was allocated to shoots of seedlings colonised by a high-uptake isolate, indicating transfer of a larger fraction of assimilated NH4 to the host than with isolates showing lower NH4 uptake rates. Thus low rates of N uptake and N transfer to the host may enable EM fungi avoid stress induced by elevated levels of nitrogen. Seedlings colonised by S. bovinus transferred a larger fraction of the 15N label to the shoots than seedlings colonised by P. involutus. Seedling shoot growth probably constituted a greater carbon sink in pot cultures than in microcosms, since the mycelial growth of P. involutus was more sensitive to high NH4 in pots. There was no homology in mycelial growth rate between pure culture and growth in symbiosis, but N uptake in pure culture corresponded to that during growth in symbiosis. No relationship was found between deposition of antropogenic nitrogen at the sites of origin of the P. involutus isolates and their mycelial growth or uptake of inorganic nitrogen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050237
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Mycorrhizae in Adenostoma fasciculatum Hook. & Arn.: a combination of unusual ecto- and endo-forms (1999)
    Springer
    Mycorrhiza 8 (1999), S. 225-228 
    Details
    ISSN: 1432-1890
    Keywords: Key words Adenostoma fasciculatum ; Ectomycorrhizae ; Arbuscular mycorrhizae ; Chaparral
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The mycorrhizal status of Adenostoma fasciculatum, the dominant shrub in California chaparral, has been unclear. In two typical, nearly monospecificstands, A. fasciculatum was found to have arbuscules and intercellular hyphae. Antisera detected hyphae of the arbuscular mycorrhizal (AM) fungal genera Acaulospora, Glomus, and Scutellospora, although we found only spores of Glomus. Some roots had partial sheaths and inter- and intracellular septate fungi without indications of root necrosis. Ectomycorrhizal root tips were also found, including Cenococcum and other unknown taxa. Sporocarps of EM fungi including species of Rhizopogon, Pisolithus, Balsamia, Laccaria, Hygrophorus, and Cortinarius were found in the stand, with no other EM or arbutoid mycorrhizal plants nearby. These observations indicate that A. fasciculatum forms mycorrhizae with AM, septate, and EM fungi, but often fails to form easily recognizable mycorrhizal structures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050238
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Comparative studies of ectomycorrhiza formation in Alnus glutinosa and Pinus resinosa with Paxillus involutus (1999)
    Springer
    Mycorrhiza 8 (1999), S. 229-240 
    Details
    ISSN: 1432-1890
    Keywords: Key words Black alder ; Red pine ; Structure ; Hartig net ; Compatibility ; Mycorrhiza
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Mycorrhiza ontogeny and details of Hartig net and mantle structure were compared in ectomycorrhizas synthesized in growth pouches between the broad host range fungus Paxillus involutus and the tree species European black alder (Alnus glutinosa) and red pine (Pinus resinosa). In Alnus glutinosa, a paraepidermal Hartig net was restricted to the proximal (basal) portion of first-order laterals; the hypodermal layer appeared to be a barrier to fungal penetration. Phi-thickenings were present in some cortical cells but these were not related to lack of fungal ingress into the cortex. The mantle was often present close to the root apex but in many roots it was loosely organized and patchy. In several instances, the mantle formed around the root apex was only temporary; renewed root growth occurred without the formation of a mantle. In Pinus resinosa, the Hartig net developed between cortical cell layers of monopodial and dichotomously branched first–order laterals. Fungal hyphae in the Hartig net exhibited a complex labyrinthine mode of growth. The mantle had a pseudoparenchymatous structure and covered the root, including apices of dichotomously branched roots. The Paxillus–Pinus resinosa interaction had all the characteristics of a compatible ectomycorrhizal association. The Paxillus–Alnus glutinosa interaction, however, showed only aspects of superficial ectomycorrhizas, including the presence of a minimal (sometimes absent) and mostly proximal Hartig net and variable mantle development. Sclerotia were produced in the extraradical mycelium of Paxillus involutus when associated with either Alnus glutinosa or Pinus resinosa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050239
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Mycorrhizal influence on protein and lipid of durum wheat grown at different soil phosphorus levels (1999)
    Springer
    Mycorrhiza 9 (1999), S. 97-101 
    Details
    ISSN: 1432-1890
    Keywords: Key words Glomus mosseae ; Lipid ; Phosphorus ; Protein ; Seed ; Triticum durum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Root colonization by arbuscular mycorrhizal fungi (AMF) may affect protein and lipid composition of plants by altering P nutrition or by eliciting other metabolic responses in the host plant. This study was conducted to determine the effects of an AMF and soil P on seed protein and lipid contents and yield of two genotypes of durum wheat (Triticum durum L.). Plants were grown in a greenhouse using soil: sand mixes with different levels of P, and with or without the AMF Glomus mosseae [(Nicol. and Gerd.) Gerd. and Trappe]. Percentage AMF root colonization decreased as P added to soil increased. The wheat genotype CR057 had higher AMF root colonization but lower seed P and protein concentrations than CR006. Without added soil P, protein concentration was significantly lower and lipid concentration and seed dry weight higher in arbuscular mycorrhizal (AM) than in nonAM plants. Seed lipid and protein contents were highly correlated with P content of plants. In nonAM plants, seed lipid and protein contents were low with no added soil P and did not differ with added soil P. Seed protein/lipid (Pro/L) concentration ratios of AM plants were higher than those of nonAM plants only when no P was added to the soil. The data indicate different patterns of seed P accumulation and different relationships between seed P and protein and lipid in AM and nonAM plants. Thus, both the presence and degree of AMF root colonization affected seed lipid metabolism in these durum wheat genotypes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050006
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Growth response of Afzelia africana Sm. seedlings to ectomycorrhizal inoculation in a nutrient-deficient soil (1999)
    Springer
    Mycorrhiza 9 (1999), S. 91-95 
    Details
    ISSN: 1432-1890
    Keywords: Key words Afzelia africana ; Provenances ; Scleroderma spp. ; Plant growth ; Mineral nutrition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The growth and mineral nutrition responses of seedlings of two provenances of Afzelia africana Sm. from Senegal and Burkina Faso, inoculated with four ectomycorrhizal (ECM) fungi (Scleroderma spp. and an unidentified isolate) from the same regions were assessed in a pot experiment in a savanna ECM-propagule-free soil deficient in NPK. There was little variation in the ability of the different fungal species to colonize roots of either provenance of A. africana or to produce external hyphal in soil. Root colonization by ECM fungi and their hyphal development were not related to mineral nutrition or ECM dependency. Differences in P, N, Mg and Ca concentrations in the leaves of inoculated and non-inoculated Afzelia seedlings were not always associated with production of biomass. Only leaf K concentration increased in both provenances after ECM inoculation. However, the Burkina Faso provenance responded better to inoculation with the two fungal isolates than the Senegal provenance in terms of biomass production. This was due to stimulation of root dry weight of the Burkina Faso provenance. Therefore, the hypothesis arises that non-nutritional rather than nutritional effects explain the contribution of ECM inoculation to the growth of A. africana seedlings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050005
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    Effect of arbuscular mycorrhizal fungi on the acclimatization of micropropagated banana plantlets (1999)
    Springer
    Mycorrhiza 9 (1999), S. 119-123 
    Details
    ISSN: 1432-1890
    Keywords: Key words Musa spp. ; Endomycorrhiza ; Glomales ; Acclimatization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The effect of arbuscular mycorrhizal fungi (AMF) on micropropagated banana plantlets was evaluated during the acclimatization period. Plants were inoculated with Acaulospora scrobiculata, Glomus clarum or Glomus etunicatum. After cultivation in a greenhouse for 3 months, height, leaf area, fresh weight and dry matter of root and shoots, level of AMF colonization, nutrient level, photosynthesis and transpiration rate, water potential and stomatal conductance were measured. The number of AMF spores produced in each treatment was also determined. Plantlets inoculated with AMF had greater height, leaf area and fresh weight of shoots and roots, as well as higher rates of photosynthesis and transpiration than controls. Plants inoculated with Glomus were superior in most of the evaluated parameters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050009
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    Intraspecific physiological variation: implications for understanding functional diversity in ectomycorrhizal fungi (1999)
    Springer
    Mycorrhiza 9 (1999), S. 125-135 
    Details
    ISSN: 1432-1890
    Keywords: Key words Mycelial growth ; Metal sensitivity ; Enzyme activities ; Gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Several thousand fungal species worlwide are thought to form ectomycorrhizas (ECM) with tree hosts and there is currently much interest in determining the functional significance of such diversity in natural and managed ecosystems. While only a few taxa have been investigated in detail, it is clear that ECM fungi display extensive intraspecific variation in a range of physiological and other life-history parameters. Thus, comparative investigations of single (or even a few) isolates of different species are unlikely to provide reliable information on functional capabilities. Extensive screening of taxonomically well-defined isolates is required. This must take into account spatial and temporal variation in gene expression in mycelia growing in axenic culture or in association with a host plant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050297
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    Occurrence of arbuscular mycorrhiza in Castanospermum australe A. Cunn. & C. Fraser and effects on growth and production of castanospermine (1999)
    Springer
    Mycorrhiza 9 (1999), S. 111-117 
    Details
    ISSN: 1432-1890
    Keywords: Key words Arbuscular mycorrhiza ; Castanospermum australe ; Castanospermine ; Alkaloid ; Anti-aids virus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Castanospermum australe A. Cunn. & C. Fraser is the only species of the genus Castanospermum (the Moreton Bay chestnut or black bean) native to NE Australia. One constituent of the plant, castanospermine, can inhibit the AIDS virus. The present study investigated possible symbioses between its roots and arbuscular mycorrhizal (AM) fungi. The effects of mycorrhizal fungi on the growth of the plant and yield of alkaloid castanospermine were also studied. The mycorrhizosphere soil and roots of C. australe collected from various sites in and around Sydney, Australia showed AM symbiotic associations with roots, with arbuscules and vesicles in the root cortices. Wet sieving and decanting yielded AM fungal spores, mainly Glomus spp. A positive correlation was found between AM fungal infection and the castanospermine content of seeds of field-grown trees. Field study results were confirmed by growing seedlings under greenhouse conditions and inoculating them with Glomus intraradices Schenck and Smith (INVAM isolate KS906) and Gigaspora margarita Becker & Hall (INVAM isolate BR444–2). The AM fungi increased the growth and P contents of plants and the yield of castanospermine in the leaves, irrespective of the P treatment. No correlation was found between the alkaloid contents of leaves from mycorrhizal seedlings and from non-mycorrhizal plants which received P. No significant difference in the production of castanospermine was found between P treatments when G. margarita was used as inoculum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050008
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Competition between ectomycorrhizal fungi colonizing Pinus densiflora (1999)
    Springer
    Mycorrhiza 9 (1999), S. 151-159 
    Details
    ISSN: 1432-1890
    Keywords: Key words Ectomycorrhiza ; Competition ; Pinus densiflora ; Japanese red pine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Interactive competition of Pisolithus tinctorius (Pers.) Coker et Couch with an unidentified species Tanashi 01 and Suillus luteus (L.: Fr.) S. F. Gray was investigated using a rhizobox. Pinus densiflora Sieb. et Zucc. was used as the host plant and mycelia were distinguished by hyphal color. The speed of mycelial spread differed between the fungi;P. tinctorius and Tanashi 01 grew faster than S. luteus. A P. tinctorius mycorrhizal seedling and a Tanashi 01 mycorrhizal seedling were transplanted on opposite sides of the rhizobox. The mycelia and mycorrhizae of P. tinctorius were overgrown by Tanashi 01 hyphae and development of P. tinctorius was gradually inhibited. The areas occupied by mycelia and mycorrhiza of P. tinctorius decreased by 52% and 37%, respectively, 154 days after transplantation relative to that at 91 days. In the overlap area of P. tinctorius and Tanashi 01, the latter fungus infected new root tips emerging from P. tinctorius mycorrhiza, which lacked a mantle of P. tinctorius hyphae, and formed a composite mycorrhizal structure. P. tinctorius mycorrhizae were progressively replaced by Tanashi 01 mycorrhizae. Mycelial spread of P. tinctorius and S. luteus were naturally inhibited but there was no interaction in mycorrhizal formation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050300
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Organic nitrogen use by salal ericoid mycorrhizal fungi from northern Vancouver Island and impacts on growth in vitro of Gaultheria shallon (1999)
    Springer
    Mycorrhiza 9 (1999), S. 145-149 
    Details
    ISSN: 1432-1890
    Keywords: Key words Gaultheria shallon ; Organic nitrogen use ; Ericoid mycorrhiza ; Salal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Salal (Gaultheria shallon) recovers quickly from rhizomes after clear-cut timber harvesting and dominates clearcuts of Tsuga heterophylla and Thuja plicata forests. Thus it contributes to considerable problems in regeneration of these sites in coastal British Columbia, Canada. Based on what is known about other ericaceous plants, we speculated that mycorrhizal fungi of salal play a vital role in the growth and dominance of salal by providing access to organic nitrogen. In this study, the ability of four species of fungi isolated from salal to use different forms of organic nitrogen was tested in pure culture and in association with salal. The organic forms of nitrogen applied were glutamine (an amino acid), glutathione (a peptide), and bovine serum albumin (BSA, a protein). The fungi tested were Oidiodendron maius, Acremonium strictum, and two nonsporulating fungi. Inoculated plants always grew better than noninoculated plants regardless of nitrogen source. Glutamine was used as readily as ammonium nitrogen by all four fungi and the mycorrhizal plants of salal colonized by those fungi. There was considerable variation between fungus species or the plants inoculated with those fungi in using glutathione and BSA. Salal inoculated with O. maius grew better on glutathione than BSA, while A. strictum and unknown 1 produced significantly greater yields of salal on BSA. Colonization rates of salal by all four fungi was higher on glutathione or BSA than on ammonium or glutamine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050299
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Effect of mycorrhizal colonization and phosphorus on ethylene production by snapdragon (Antirrhinum majus L.) flowers (1999)
    Springer
    Mycorrhiza 9 (1999), S. 161-166 
    Details
    ISSN: 1432-1890
    Keywords: Key words Vase-life ; Ethylene sensitivity ; Postharvest quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  We determined the effects of phosphorus (P) concentration and mycorrhizal colonization on ethylene production by flowers of snapdragons (Antirrhinum majus L.). Mycorrhizal colonization in a soil-less medium did not significantly affect the total number of flowers per spike or flower P concentration, but it significantly increased flower vase-life and significantly decreased flower ethylene production. This demonstrates for the first time that mycorrhizal colonization can have a non-localized effect on host ethylene production. The reduction in ethylene production caused by mycorrhizal colonization was as large as the variation in ethylene production among snapdragon cultivars. Thus, mycorrhizal colonization may be a viable alternative to toxic ethylene inhibitors such as silver thiosulfate. Increased fertilizer P concentration (15 versus 3 μg P ml–1) significantly increased plant fresh weight and the total number of flowers per spike. In contrast to mycorrhizal colonization, increased fertilizer P concentration resulted in an increase in ethylene production. There was no significant effect of fertilizer P concentration on vase-life. This suggests that factors other than ethylene have at least partial control over vase-life. Postharvest amendment of individual flowers with phosphate also significantly increased flower ethylene production. Phosphorus apparently does not mediate the mycorrhizal effect because mycorrhizal colonization decreased ethylene production without significantly influencing flower P concentration. Moreover, treatment with phosphate increased flower ethylene production. Mycorrhizal colonization did not significantly influence response to exogenous ethylene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050301
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Exudation-reabsorption in a mycorrhizal fungus, the dynamic interface for interaction with soil and soil microorganisms (1999)
    Springer
    Mycorrhiza 9 (1999), S. 137-144 
    Details
    ISSN: 1432-1890
    Keywords: Key word Exudation ; Reabsorption ; Mycelium-soil interface ; Osmotic gradient pump ; Carbon and water translocation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The mycelium of Suillus bovinus slowly absorbed [U-14C]glucose and other tracers from droplets placed on the cords, translocated them to the peripheral hyphae and exuded them into fluid drops on the hyphal tips. The exudate was characterized by 1H NMR spectroscopy and by sugar and amino acid analysis. The exuded compounds were mainly carbohydrates and peptides. Acetic acid and oxalic acid were also present in the exudate along with a number of unidentified compounds. Released ions (K, Na, Cl, P, Mg and Ca) were identified by X-ray microanalysis. The mycelium was shown to reabsorb up to 65% of the exuded 14C compounds in 2 days. Glucose, mannitol, glutamic acid (pH 3.2), and Rb+ (as well as other mineral ions) were all readily absorbed by the mycelium, while oxalic acid at pH 4.2 and glutamic acid at pH 6.5 were not. Exudation of fluid droplets on the surface of the hydrophobic mycorrhizal fungus S. bovinus may represent an ecophysiologically important function of the extramatrical hyphae, which provides an interface for interaction with the immediate hyphal environment and its other microorganisms where the peripheral hyphae exchange their photosynthetically derived products for nutrients to be used later by the pine host. We hypothesize that actively absorbed carbohydrates from the root are translocated to the peripheral hyphae along a concentration gradient of sugars and polyols by means of active translocation and diffusion in cell elements and by acropetal water transport in the cord vessels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050298
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    In vitro ectomycorrhiza formation between Abies firma and Pisolithus tinctorius (1999)
    Springer
    Mycorrhiza 9 (1999), S. 177-183 
    Details
    ISSN: 1432-1890
    Keywords: Key words Japanese fir ; Momi fir ; Ectomycorrhizas ; In vitro culture ; Kotsubutake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The first in vitro aseptic synthesis of Abies firma Sieb. et Zucc. with Pisolithus tinctorius (Pers.) Coker & Couch is reported. Techniques were improved for the aseptic synthesis of ectomycorrhizas of A. firma, a slow-growing species in vitro, and Pisolithus tinctorius using a novel culture medium and both sterilized and re-rooted seedlings. After 2–3 months incubation, ectomycorrhizas were formed by both methods. The mycorrhizas possessed a mantle and a highly branched nonseptate Hartig net mycelium colonizing the intercellular spaces within the host cortex, features characteristic of ectomycorrhizas. These techniques will prove useful for addressing physiological and biochemical questions on the interactions of microbes with roots of whole plants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050303
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Effects of mycorrhizal fungus isolates on mineral acquisition by Panicum virgatum in acidic soil (1999)
    Springer
    Mycorrhiza 9 (1999), S. 167-176 
    Details
    ISSN: 1432-1890
    Keywords: Key words Acaulospora ; Gigaspora ; Glomus ; Alleviation of toxic minerals ; Mineral nutrient concentrations ; Low pH soil ; Switchgrass
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Plant ability to withstand acidic soil mineral deficiencies and toxicities can be enhanced by root-arbuscular mycorrhizal fungus (AMF) symbioses. The AMF benefits to plants may be attributed to enhanced plant acquisition of mineral nutrients essential to plant growth and restricted acquisition of toxic elements. Switchgrass (Panicum virgatum L.) was grown in pHCa (soil:10 mM CaCl2, 1 : 1) 4 and 5 soil (Typic Hapludult) inoculated with Glomus clarum, G. diaphanum, G. etunicatum, G. intraradices, Gigaspora albida, Gi. margarita, Gi. rosea, and Acaulospora morrowiae to determine differences among AMF isolates for mineral acquisition. Shoots of mycorrhizal (AM) plants had 6.2-fold P concentration differences when grown in pHCa 4 soil and 2.9-fold in pHCa 5 soil. Acquisition trends for the other mineral nutrients essential for plant growth were similar for AM plants grown in pHCa 4 and 5 soil, and differences among AMF isolates were generally higher for plants grown in pHCa 4 than in pHCa 5 soil. Both declines and increases in shoot concentrations of N, S, K, Ca, Mg, Zn, Cu, and Mn relative to nonmycorrhizal (nonAM) plants were noted for many AM plants. Differences among AM plants for N and Mg concentrations were relatively small (〈2-fold) and were large (2- to 9-fold) for the other minerals. Shoot concentrations of mineral nutrients did not relate well to dry matter produced or to percentage root colonization. Except for Mn and one AMF isolate, shoot concentrations of Mn, Fe, B, and Al in AM plants were lower than in nonAM plants, and differences among AM plants for these minerals ranged from a low of 1.8-fold for Fe to as high as 6.9-fold for Mn. Some AMF isolates were effective in overcoming acidic soil mineral deficiency and toxicity problems that commonly occur with plants grown in acidic soil.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050302
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    The mycorrhizal status of an emergent aquatic, Lythrum salicaria L., at different levels of phosphorus availability (1999)
    Springer
    Mycorrhiza 9 (1999), S. 191-197 
    Details
    ISSN: 1432-1890
    Keywords: Key words Arbuscular mycorrhizae ; Lythrumsalicaria ; Phosphorus ; Wetland ; Emergent aquatic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The relationship between nutrient availability and mycorrhizal status has been well studied for terrestrial plant species, but has been examined rarely in aquatic and emergent aquatic species. The purpose of this study was to determine the effect of phosphorus availability on the arbuscular mycorrhizal (AM) status of an emergent aquatic, Lythrum salicaria L. L. salicaria was grown in hydroponic sand culture at five phosphorus concentrations (0, 100, 1000, 10 000, and 47 500 μg PO4/l nutrient solution) for 49 days with or without mycorrhizal inoculum obtained from wetland soil. Inoculated plants at the lowest three phosphorus concentrations were colonized by AM, whereas there was no colonization of plants grown at the highest two phosphorus concentrations. Colonization by AM fungi occurred in conjunction with symptoms of phosphorus deficiency in L. salicaria under experimental conditions: plants at the lowest three phosphorus concentrations had lower biomass and higher root: shoot weight ratios than plants at the highest two concentrations. However, total biomass and internal phosphorus concentration did not differ between inoculated and control plants. Further studies are needed under conditions more closely mimicking natural dynamics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050266
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Influence of soil impoverishment on the interaction between Glomus mosseae and saprobe fungi (1999)
    Springer
    Mycorrhiza 9 (1999), S. 185-189 
    Details
    ISSN: 1432-1890
    Keywords: Key words Arbuscular mycorrhizas ; Glomus mosseae ; Saprobe fungi ; Glycine max
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The effect of the saprobe fungi Wardomyces inflatus (Marchal) Hennebert, Paecilomyces farinosus (Holm & Gray) A. H. S. Brown & G. Sm., Gliocladium roseum Bain., Trichoderma pseudokoningii Rifai and T. harzianum Rifai, isolated from sporocarps of Glomus mosseae, on arbuscular mycorrhizal (AM) colonisation and plant dry matter of soybean was studied in 2/3 and 1/5 diluted soils in a greenhouse trial. Soil dilution to 1/5 had no effect on shoot dry matter of soybean but decreased AM colonisation and root dry weight of plants. CFU of saprobe fungi, except T. harzianum, were higher in 1/5 than in 2/3 diluted soils. W. inflatus and Gliocladium roseum decreased the shoot dry weight of soybean plant when inoculated together with Glomus mosseae. The saprobe fungi P. farinosus and T. pseudokoningii increased the shoot dry weights of plants grown in 1/5 diluted soil. The shoot dry weight and AM colonisation in 1/5 diluted soil were also increased when T. harzianum was inoculated together with Glomus mosseae. Thus, saprobe fungi increased AM colonisation of soybean plants by indigenous endophytes. The AM colonisation of plants at both soil dilutions was increased by Glomus mosseae. The highest level of AM colonisation was observed when P. farinosus and T. pseudokoningii were inoculated together Glomus mosseae. The dilution of soils influenced the interaction between inoculated microorganisms and their effect on plant growth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050265
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Pisolithus arhizus ectomycorrhiza affects plant competition for phosphorus between Pinus elliottii and Panicum chamaelonche (1999)
    Springer
    Mycorrhiza 9 (1999), S. 199-204 
    Details
    ISSN: 1432-1890
    Keywords: Key words Competition ; Ectomycorrhiza ; External hyphae ; Phosphorus ; Pisolithus arhizus ; Uptake kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Our objective was to evaluate the ability of an ectomycorrhizal fungus to alter the competitive interaction of pine seedlings growing with grass, and to determine whether the interaction was modified by soil-phosphorus (P) concentration. Slash pine (Pinus elliottii), inoculated with the ectomycorrhizal fungus Pisolithus arhizus or fortuitously colonized by Thelephora terrestris, and a native grass (Panicum chamaelonche) were grown in a greenhouse at three P levels (0.32, 3.22, 32.26 μM H3PO4). Pine inoculated with P. arhizus took up more P when competing with the nonmycorrhizal grass than when competing with another pine (irrespective of pine mycorrhizal status). Phosphorus uptake kinetics (Cmin, the minimum concentration at which P can be absorbed from a solution; Imax, the maximum uptake rate) for pine and grass were also determined under hydroponic conditions. Pine had a higher Imax than grass but grass had a lower Cmin, suggesting that pine is more competitive at higher nutrient concentrations while grass is more competitive at lower nutrient concentrations. The controlled conditions used in these experiments allowed us to evaluate specific parameters (P uptake and absorbing surface area) affecting plant competition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050267
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Visualisation of mycorrhizal fungal structures and quantification of their surface area and volume using laser scanning confocal microscopy (1999)
    Springer
    Mycorrhiza 9 (1999), S. 205-213 
    Details
    ISSN: 1432-1890
    Keywords: Key words Arbuscular mycorrhiza ; Staining ; Visualisation ; Confocal microscopy ; Quantification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  A method has been developed for the visualisation and three-dimensional (3D) measurement of mycorrhizal fungal structures inside plant roots. Sections of Allium porrum L. roots colonised by Glomus sp. 'City Beach' (WUM 16) and Lilium sp. roots colonised by Scutellospora calospora (Nicol. & Gerd.) Walker & Sanders (WUM 12(2)) were stained with acid fuchsin. This allowed fluorescence from the fungal structures to be observed under a laser scanning confocal microscope (LSCM) without interference from the plant cells. A series of horizontal optical sections were collected from a Glomus sp. arbuscule and from a hyphal coil of S. calospora. These data were used to produce extended focus images. Axial distortion in microscopic visualisation due to the refractive index mismatch between the immersion and mounting media was quantified using vertical scanning of the hyphae. A correction factor of 0.71 μm was used for the z-interval between the xy-slices. A series of binary xy-images from each structure was rendered into a 3D graphical model for viewing. The volume and surface area of the structures were estimated using computerised 3D measurement and also by stereological integration of binary xy-images. With both structures, the surface area estimates varied greatly between the two measuring systems, whereas differences in volume estimates were small. Computerised 3D measurement was considered more accurate than stereological integration of confocal binary images.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050268
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    The relationship between density of Glomus mosseae propagules and the initiation and spread of arbuscular mycorrhizas in cotton roots (1999)
    Springer
    Mycorrhiza 9 (1999), S. 221-225 
    Details
    ISSN: 1432-1890
    Keywords: Key words AM fungi ; Inoculum density ; Initiation of AM ; Spread of AM ; Cotton
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The experiments aimed to determine the relationship between density of propagules in soil and initiation and spread of an arbuscular mycorrhizal fungus in the cotton roots. As few as 10 propagules of Glomus mosseae in approximately 95 g soil located in a band 25 cm below the soil surface established mycorrhizas in more than 80% of cotton roots at the point of inoculation within 36 days. Secondary spread was initiated 10–13 days after primary colonisation in treatments inoculated with one, 10 or 100 propagules. Spread of mycorrhizas within the root system was rapid from 100 propagules and was slower with fewer propagules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050270
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    Mycorrhizal effects on the acclimatization, survival, growth and chlorophyll of micropropagated Syngonium and Draceana inoculated at weaning and hardening stages (1999)
    Springer
    Mycorrhiza 9 (1999), S. 215-219 
    Details
    ISSN: 1432-1890
    Keywords: Key words Mixed indigenous consortium ; Micropropagated plants ; Acclimatization period ; Substrate fertility ; Chlorophyll content
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Micropropagated plantlets of Syngonium podophyllum and Draceana sp. were inoculated during an early weaning stage of acclimatization with a mixed indigenous consortium of arbuscular mycorrhizal (AM) fungi. Both species were colonized but a significantly higher colonization was observed (38%) in Draceana than S. podophyllum when it was harvested after 20 weeks. Draceana plants showed little difference in the extent to which they were colonized, when examined either at the weaning stage or hardening stage; however, S. podophyllum plants at the weaning stage were better colonized than at 20 weeks. Survival was high in inoculated plants at lower fertility in both hosts. Moreover, S. podophyllum showed better stolon production than uninoculated controls at both fertility levels, though the increase was higher at lower fertility. Draceana showed no response in shoot height to any treatment. Chlorophyll accumulation in both hosts was significantly influenced by inoculation, fertility and stage (weaning and hardening). A significant increment in shoot P uptake was also observed in both hosts related to inoculation, stage and fertility. Inoculation with the AM consortium had a significant and favourable effect on acclimatization of micropropagated S. podophyllum and Draceana at the weaning stage, saving almost 15 days in the total hardening process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050269
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    Tricholoma matsutake– an assessment of in situ and in vitro infection by observing cleared and stained whole roots (1999)
    Springer
    Mycorrhiza 9 (1999), S. 227-231 
    Details
    ISSN: 1432-1890
    Keywords: Key words Ectomycorrhiza ; Hartig net ; Matsutake ; Pinus densiflora ; Tricholoma matsutake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Structures present within field-collected Tricholoma matsutake/Pinus densiflora ectomycorrhizas and in vitro infections of P. densiflora roots by T. matsutake were observed by clearing, bleaching and staining whole lateral roots and mycorrhizas. Field mycorrhizas were characterized by a lack of root hairs, by the presence of a sparse discontinuous mantle composed of irregularly darkly staining hyphae over the root surface, primarily behind the root cap, and by the presence of Hartig net mycelium within the root cortex. Hartig net 'palmettis' were classified into three basic structures, each with distinctive morphologies. Aerial hyphae, bearing terminal swellings, were observed emanating from the mantle. Cleared, bleached and stained in vitro-infected roots possessed multibranched hyphal structures within the host root cortex and aerial hyphae bearing terminal swellings were observed arising from the mycelium colonizing the root surface. T. matsutake on P. densiflora conforms to the accepted morphology of an ectomycorrhiza. This staining protocol is particularly suited to the study of Matsutake mycorrhizal roots and gives rapid, clear, high-contrast images using standard light microscopy while conserving spatial relationships between hyphal elements and host tissues.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050271
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    The mycorrhizal colonization of six wetland plant species at sites differing in land use history (1999)
    Springer
    Mycorrhiza 9 (1999), S. 233-235 
    Details
    ISSN: 1432-1890
    Keywords: Key words Wetlands ; Mycorrhizal fungi ; Land use history ; Restoration ecology ; Soil ecology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Five wetland prairie sites and six native plant species in western Oregon were examined to determine patterns of vesicular-arbuscular mycorrhizal fungal (VAMF) colonization. The sites differed in type and intensity of past land use. VAMF colonization was tested in situ on seedlings from both field-sown seeds and from transplants. Colonization was measured as the percentage of root length with arbuscles or vesicles. All species (Deschampsia cespitosa, Downingia elegans, Eriophyllum lanatum, Hordeum brachyantherum, Microseris laciniata, and Plagiobothrys figuratus) became colonized by VAMF during the study. This is the first report of mycorrhizal colonization of these important native species. All sites supported mycorrhizal colonization of some of the experimental species. Average VAMF colonization ranged from 58% to 92% but was unrelated to subjective rankings of land use intensity. These results suggest that VAMF inoculum at all sites was sufficient to support revegetation by at least some species of native plants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050272
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Presence of arbuscular mycorrhizas in typically ectomycorrhizal host species from Cameroon and New Zealand (1999)
    Springer
    Mycorrhiza 8 (1999), S. 247-253 
    Details
    ISSN: 1432-1890
    Keywords: Key words Ectomycorrhiza ; Arbuscular mycorrhiza ; Saplings ; Tropical ; Temperate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Ectomycorrhizas (EcM) and arbuscular mycorrhizas (AM) were screened for in saplings of 14 EcM tree species from the N'Dupé and Korup National Park rainforests, SW Cameroon, belonging to Caesalpiniaceae and Uapacaceae. The pattern of EcM and AM colonisation of a dual mycorrhizal species from this rainforest (Uapaca staudtii, Uapacaceae) was compared with dual EcM/AM colonisation of Leptospermum scoparium (Myrtaceae) from New Zealand. Both species were collected in a range of habitats. EcM and AM colonisation differed among species in the Korup National Park rainforest: 12 species belonging to the Caesalpiniaceae (Amherstieae) were consistently EcM, and AM structures occurred occasionally in six of them; two other species belonging to Caesalpiniaceae (Afzelia bipindensis) and Uapacaceae (U. staudtii) were dual mycorrhizal with variable levels of colonisation by both EcM and AM fungi. EcM and AM dual colonisation varied with both habitat and identity of the partners. The presence of EcM fungi in most of the root samples of U. staudtii and a negative relationship between AM and EcM colonisation within the same root system suggested a greater EcM affinity of this species. In contrast, most root samples of L. scoparium were colonised by AM, but only a few by EcM. Genuine dual EcM/AM associations in root samples of U. staudtii where the two mycorrhizal types co-occurred could be attributed to an AM-EcM succession. However, differences between predicted and observed frequencies of genuine dual EcM/AM associations in several samples of both U. staudtii and L. scoparium indicated that other factors influenced dual EcM/AM associations. The results of this study showed the importance of the identity of the host species in determining the pattern of dual EcM and AM colonisation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050241
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Fruiting of putative ectomycorrhizal fungi under blue gum (Eucalyptus globulus) plantations of different ages in Western Australia (1999)
    Springer
    Mycorrhiza 8 (1999), S. 255-261 
    Details
    ISSN: 1432-1890
    Keywords: Key words Blue gum plantation ; Ectomycorrhizal fungus sporocarps ; Species richness ; Eucalyptus globulus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The species richness of putative ectomycorrhizal (EM) fungi fruiting in blue gum (Eucalyptus globulus Labill.) plantations in Western Australia was investigated in relation to plantation age. Eleven plantations, 1–8 years old, were selected for study and two native Eucalyptus forest sites in the same region were chosen for comparison. Sporocarps of 44 species of putative EM fungi were collected from the 13 sites. Of these, 30 species were found in blue gum plantations. The number of fungal species was highly positively correlated with plantation age and inversely correlated with soil pH. Young plantations (1–5 years) had 2–9 fungal species and were overwhelmingly dominated by species of Laccaria and Scleroderma. In older plantations (6–8 years), the relative abundance of sporocarps of each species within the fungal community decreased, accompanied by an increase in the number of fungal species (12–17 per site). A brief survey of the two native eucalypt forests in this region revealed a much higher number of fungal species than that observed in plantations. In plantations, species of Descolea, Laccaria, Pisolithus and Scleroderma typically fruited in young plantations. Species of epigeous fungi of the genera Boletus, Cortinarius, Hydnum, Inocybe, Lactarius, Paxillus, Russula and hypogeous fungi, including species of Descomyces, Hysterangium and Mesophellia, were found only in older plantations, or in native forests. Some of the fungi that fruit in young plantations are now being evaluated for use in commercial spore inoculation programs to increase the species diversity of EM fungi in exotic eucalypt plantations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050242
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Viability of ectomycorrhizal fungus mycelium entrapped in calcium alginate gel (1999)
    Springer
    Mycorrhiza 8 (1999), S. 263-266 
    Details
    ISSN: 1432-1890
    Keywords: Key words Hebeloma crustuliniforme ; Inoculum production ; Inoculum storage ; Pisolithus tinctorius ; Paxillus involutus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  We studied the viability of fragmented mycelium of Pisolithus tinctorius and Paxillus involutus entrapped in calcium alginate gel to determine the efficacy of this method of producing ectomycorrhizal fungus inoculum. Fungi were grown in MMN solution at 28  °C before being fragmented in a blender and subsequently entrapped in calcium alginate. We tested different ratios of alginate and mycelium suspension to 0.7 M CaCl2. The ratio 8 : 10 resulted in well-formed beads of the highest viability for Paxillus involutus (99%) and for Pisolithus tinctorius (75%). Paxillus involutus mycelium was more than 90% viable when entrapped mycelium was 10 to 50 days old, and Pisolithus tinctorius attained its highest viability (55%) for 20- to 40-day-old mycelium. Gel entrapped Paxillus involutus mycelium grew well at all temperatures after 30 days of storage, but viability significantly decreased after 60 days storage at 6  °C on dry filter paper. For gel-entrapped Pisolithus tinctorius mycelium, viability was highest when stored at 25  °C in 0.7 M CaCl2. Entrapment of Paxillus involutus fragmented mycelium in calcium alginate beads under the conditions that we propose can be used successfully to produce inoculum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050243
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Abundance of arbuscular mycorrhizal fungi spores in different environments in a tropical rain forest, Veracruz, Mexico (1999)
    Springer
    Mycorrhiza 8 (1999), S. 267-270 
    Details
    ISSN: 1432-1890
    Keywords: Key words Arbuscular mycorrhizae ; Tropical rain forest ; Gaps ; Mexico
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The aim of this study was to compare mycorrhizal abundance and diversity in sites with different regimes of disturbance in a tropical rain forest at Los Tuxtlas, Veracruz, Mexico. Arbuscular mycorrhizal spores were quantified at two sites: closed canopy and gaps in the forest. Data were recorded during dry, rainy, and windy ("nortes") seasons. Spores of eight Glomus species, sporocarps of three Sclerocystis species, three species of Acaulospora and two of Gigaspora were found. Significant differences in the number of species and spores were found among seasons. The highest numbers of species and spores were observed during the dry season, with a marked decrease during the rainy season. Our results show that disturbance does not but seasonality does affect abundance and richness of mycorrhizal spores in this tropical wet forest.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050244
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Ectomycorrhizal fungi of Pinus pinea L. in northeastern Spain (1999)
    Springer
    Mycorrhiza 8 (1999), S. 271-276 
    Details
    ISSN: 1432-1890
    Keywords: Key words Stone pine ; Synthesis of mycorrhizas ; Containerized seedlings ; Mycelial inoculum produced in peat-vermiculite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Although Pinus pinea L. is an important forest species in the Mediterranean region, few reports exist on its ectomycorrhizal associates. Sixty isolates, obtained from fungal sporocarps collected in mixed forests of P. pinea in Catalonia (northeastern Spain), were tested for ectomycorrhiza formation on containerized P. pinea seedlings when applied as mycelial inoculum produced in peat-vermiculite. A total of 17 isolates, in 8 genera (Amanita, Hebeloma, Laccaria, Lactarius, Pisolithus, Rhizopogon, Scleroderma and Suillus), formed ectomycorrhizas and the percentages of mycorrhizal short roots varied among isolates and species from 13% to 89%. Some of these fungi are cited for the first time in association with P. pinea. The results indicate further fungal candidates for controlled inoculation of P. pinea seedlings in the nursery.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050245
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Accumulation of secondary compounds in barley and wheat roots in response to inoculation with an arbuscular mycorrhizal fungus and co-inoculation with rhizosphere bacteria (1999)
    Springer
    Mycorrhiza 8 (1999), S. 241-246 
    Details
    ISSN: 1432-1890
    Keywords: Key words Arbuscular mycorrhiza ; Hordeum vulgare ; Triticum aestivum ; Glomus intraradices ; Mycorrhiza-helper bacteria ; Secondary compounds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Colonization of Hordeum vulgare L. cv. Salome (barley)and Triticum aestivum L. cv. Caprimus (wheat) roots by the arbuscular mycorrhizal fungus Glomus intraradices Schenck & Smith leads to de novo synthesis of isoprenoid cyclohexenone derivatives with blumenin [9-O-(2′-O-β-glucuronosyl)-β-glucopyranoside of 6-(3-hydroxybutyl)-1,1,5-trimethyl-4-cyclohexen-3-one] as the major constituent and to transient accumulation of hydroxycinnamate amides (4-coumaroylagmatine and -putrescine). Accumulation of these compounds in mycorrhizal wheat roots started 2 weeks after sowing together with the onset of arbuscule formation and proceeded with mycorrhizal progression. Highest levels were reached in 3- to 4-week-old secondary roots (root branches of first and higher order) characterized by the formation of vesicles. In the final developmental stages, the fungus produced massive amounts of spores, enclosing the stele of older root parts (older than 5 weeks) characterized by cortical death. In these root parts, the secondary compounds were detected in trace amounts only, indicating that they were located in the cortical tissues. Some rhizosphere bacteria tested, i.e. Agrobacterium rhizogenes, Pseudomonas fluorescens, and Rhizobium leguminosarum, markedly stimulated both fungal root colonization and blumenin accumulation, thus, acting as mycorrhiza-helper bacteria (MHB). Application of blumenin itself strongly inhibited fungal colonization and arbuscule formation at early stages of mycorrhiza development. This was associated with a markedly reduced accumulation of the hydroxycinnamate amides 4-coumaroylputrescine and -agmatine. The results suggest that both the isoprenoid and the phenylpropanoid metabolism are closely linked to the developmental stage and the extent of fungal colonization. Their possible involvement in the regulation of mycorrhiza development is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050240
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Effect of organic and inorganic nitrogen sources on endogenous polyamines and growth of ectomycorrhizal fungi in pure culture (1999)
    Springer
    Mycorrhiza 8 (1999), S. 277-281 
    Details
    ISSN: 1432-1890
    Keywords: Key words Ectomycorrhiza ; Nitrogen ; Putrescine ; Spermidine ; Spermine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The abilities of three ectomycorrhizal fungi, Paxillus involutus, Suillus variegatus and Lactarius rufus, to utilize organic and inorganic nitrogen sources were determined by measuring the growth and endogenous free polyamines (putrescine, spermidine and spermine) of pure culture mycelium. Differences were found in the utilization of the nitrogen sources and in the polyamine concentrations between the fungal species and between isolates of L. rufus. All the fungi grew well on ammonium and on several amino acids. Endogenous polyamine levels varied with the nitrogen source. Spermidine was commonly the most abundant polyamine; however, more putrescine than spermidine was found in P. involutus growing on inorganic nitrogen or arginine. Low amounts of spermine were found in S. variegatus and some samples of L. rufus. None or only a trace of spermine was found in P. involutus mycelium. In all fungi, putrescine concentrations were higher with ammonium than with the nitrate treatment. The total nitrogen content of peat did not determine the ability of L. rufus strains isolated from peatland forest sites to utilize organic nitrogen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050246
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    ICOM2 shows that mycorrhiza research is strong! (1999)
    Springer
    Mycorrhiza 8 (1999), S. 287-288 
    Details
    ISSN: 1432-1890
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050248
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    Quantification of arbuscular mycorrhizal fungi activity by the glomalin concentration on hyphal traps (1999)
    Springer
    Mycorrhiza 8 (1999), S. 283-285 
    Details
    ISSN: 1432-1890
    Keywords: Key words Hyphae ; Protein ; Gigaspora gigantea ; Glomus intraradices ; Glomuscaledonium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Strips of horticultural film (16–32 cm2) were used to trap extraradical hyphae emanating from roots of sudangrass [Sorghum sudanense (Piper) Staph] enclosed in 40-μm mesh bags and colonized by Gigaspora rosea FL 224-1, Glomus intraradices EY 113/114, or Glomus caledonium UK 301-1. Strips of film were placed at opposite sides of 17–21 replicate sand culture pots for each isolate and were removed after 12–14 weeks of plant growth. To extract glomalin, a strip was cut into small pieces and submerged in 2 ml of 20 mM citrate, pH 7.0 and then autoclaved for 60 min. A quantitative enzyme-linked immunosorbent assay (ELISA) detected 0.005–0.04 μg glomalin in the volume of extract tested. The Bradford protein assay detected 1.25–5 μg of protein in the volume of extract tested. Both assays gave results ranging from 5–40 μg glomalin/cm2 of film. Protein assay values were correlated with ELISA values (r=0.6091, P≤0.001, n=118). Analysis of variance indicated that isolates differed in Bradford protein values (P=0.001), but not ELISA values (P=0.154). Spatial variability of glomalin deposition ca. 7 cm from roots on opposite sides of pots was indicated by significant paired T tests (P〈0.05) for protein values for each of the three isolates and ELISA for two isolates. These results indicate that hyphal traps, Bradford protein assay and ELISA are useful to assess hyphal activity over a growing season.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050247
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Plant growth and ectomycorrhiza formation by transplants on deglaciated land near Exit Glacier, Alaska (1999)
    Springer
    Mycorrhiza 8 (1999), S. 297-304 
    Details
    ISSN: 1432-1890
    Keywords: Key words Ectomycorrhizae ; Glacier ; Succession ; Chronosequence ; Alnus ; Populus ; Picea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Ectomycorrhiza (EM) formation on plant roots in successional communities may vary with plant species, plant age, and age of vegetation after disturbance. To evaluate differences in mycorrhizal fungus communities on roots of same-aged seedlings across a deglaciated chronosequence, indoor-grown bioassay plants of four dominant species Epilobium latifolium L. (dwarf fireweed), Populus balsamifera ssp. trichocarpa (Torr.&Gray) Hult. (black cottonwood), Alnus sinuata (Regel) Rydb. (Sitka alder), and Picea sitchensis (Bong.) Carr. (Sitka spruce) were transplanted into five successional stages (Barren, Isolated Plant, Patchy, Alder, and Cottonwood) following deglaciation near Exit Glacier, Alaska. The species were selected for their successional status and mycorrhiza formation potential [EM or arbuscular mycorrhiza (AM) or both]. Seedlings were transplanted in June 1992, and half were harvested at the ends of the two subsequent growing seasons. The EM communities on P. balsamifera differed across the chronosequence while those of the other species did not. Morphotype B dominated the EM on P. balsamifera after the Barren stage, and the greatest EM colonization was in the Isolated Plant and Patchy stages. No AM were found. The EM observed on even-aged seedlings in this study were a subset of the EM found on naturally occurring plants (seedlings to mature trees) in a prior study, and some were common to multiple plant species. Most plant growth responses were not significant across stages or were inconsistent among plant species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050250
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Glomalean mycorrhizal fungi from tropical Australia (1999)
    Springer
    Mycorrhiza 8 (1999), S. 305-314 
    Details
    ISSN: 1432-1890
    Keywords: Key words Vesicular-arbuscular mycorrhizas ; Glomales ; Isolation and propagation ; Tropical ecology ; Fungal diversity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  A comparison of different methods for isolation of vesicular-arbuscular mycorrhizal (VAM) fungi into open-pot cultures was undertaken as part of a study of the diversity of these fungi. Four different isolation techniques using spores separated from soil, soil trap cultures, root samples, or transplanted seedlings grown in intact soil cores were used to obtain as many fungi as possible from each site. Isolation methods were compared using paired samples from the same locations within natural (savanna, rocky hill, wetland, rainforest) and disturbed (minesite) habitats in a seasonally dry tropical region in the Northern Territory of Australia. There were large differences in (i) the efficiency (rate of increase in mycorrhizal colonisation), (ii) the proportion of successful cultures, (iii) fungal diversity (number of fungal species in each culture) and (iv) specificity (identity of species isolated) between these four procedures. However, the less-efficient procedures generally resulted in a higher proportion of cultures of one fungus, which could be used without further isolation steps. Most species of Scutellospora, Acaulospora and Gigaspora were obtained primarily from field-collected spores, but only 50% of these culture attempts were successful. Spores from these initial cultures produced mycorrhizas much more rapidly and successfully when used to start second-generation cultures. Several species of fungi, rarely recovered as living spores from field soils, were dominant in many trap cultures started from soil or roots. Most of these fungi were Glomus species, that were first distinguished by colonisation patterns in roots and eventually identified after sporulation in second- or third-generation trap cultures. These experiments demonstrated that glomalean fungi in the habitats sampled belonged to two functional categories, based on whether or not spores were important propagules. The "non-sporulating" fungi were dominant in many trap cultures, which suggests that these fungi had higher total inoculum levels in soils than other fungi. Pot-culturing methods provided additional information on fungal diversity which complemented spore occurrence data obtained using the same soil samples and provided valuable new information about the biology of these fungi.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050251
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Glomalean mycorrhizal fungi from tropical Australia (1999)
    Springer
    Mycorrhiza 8 (1999), S. 315-321 
    Details
    ISSN: 1432-1890
    Keywords: Key words Vesicular-arbuscular mycorrhizas ; Glomalean fungi ; Diversity ; Inoculum ; Tropical fungi ; Succession ; Nutrition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The isolation of vesicular-arbuscular mycorrhizal (VAM) fungi from natural (savanna, rocky hill, wetland and rainforest) and disturbed (minesite) habitats in a seasonally-dry tropical region in the Northern Territory of Australia into open-pot cultures was undertaken to supplement knowledge about the diversity of these fungi. This experiment considered factors affecting the diversity of fungi obtained in trap cultures started using diluted soil from field sites and two host plants. A range of soil phosphorus and other nutrient levels from severely deficient to sufficient for maximal growth was used to determine the impact of nutrition on mycorrhizal associations of sorghum (Sorghum sp.) and clover (Trifolium subterraneum). Soil cores taken from pots at 6-week intervals provided roots and soil to assess mycorrhiza formation and sporulation without substantial damage to plants. The identification of VAM fungi to genus by observing morphological patterns within clover roots revealed substantial differences in fungus populations between soils and a moderate effect of nutrient levels on fungal diversity. Changes in the proportion of different fungi in roots over the 31 weeks of the experiment were also observed. Glomus spp. were initially the most abundant fungi within roots, but Scutellospora spp. gradually became more dominant at later harvests, while colonisation by Acaulospora spp. was limited at all times. For both clover and sorghum, sporulation was limited and was dominated by single species of Scutellospora and Acaulospora. This contrasted with the much higher diversity of spore types in the original field soils.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050252
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    The influence of fire frequency on arbuscular mycorrhizal colonization in the shrub Dillwynia retorta (Wendland) Druce (Fabaceae) (1999)
    Springer
    Mycorrhiza 8 (1999), S. 289-296 
    Details
    ISSN: 1432-1890
    Keywords: Key words Glomalean ; Arbuscule ; Inter-fire interval ; Wildfire
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Fire regimes have three inter-related components that can affect population dynamics: frequency, intensity and season. However, there has been little effort to study the effects of any of these components on arbuscular mycorrhizas (AM). In order to examine the long-term effects of fire frequency on AM colonization, the roots of Dillwynia retorta were examined at 32 sites supporting Hawkesbury Sandstone vegetation in the Sydney region of southeastern Australia. These sites were representative of the broad-scale variability in fire frequencies with respect to the length and timing of inter-fire intervals found in the Sydney region during the previous 30 years. The length of the shortest inter-fire interval was significantly correlated with total AM colonization, and the length of the longest inter-fire interval was related to the arbuscular colonization. The length of the most-recent inter-fire interval and the time since the shortest inter-fire interval were not related to AM colonization in D. retorta. Furthermore, AM colonization was directly related to the local abundance of the host plant, indicating that the effects of fire frequency on AM colonization are likely to occur indirectly via direct effects on the host plant. Canonical correspondence analysis demonstrated that the presence and abundance of alternate potential hosts had no influence on mycotrophy in D. retorta. Thus, the impact of fire on D. retorta was probably the main factor influencing its mycorrhizal status in relation to fire history.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050249
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Root morphology, anatomy and mycotrophy of the achlorophyllous Voyria aphylla (Jacq.) Pers. (Gentianaceae) (1999)
    Springer
    Mycorrhiza 9 (1999), S. 33-39 
    Details
    ISSN: 1432-1890
    Keywords: Key words Voyria ; Gentianaceae ; Root structures ; Arbuscular mycorrhiza ; Mycoheterotrophy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Roots of Voyria aphylla only develop hairs where roots of neighboring plants or organic litter are attached. Fungal penetration occurs almost exclusively at these root-to-root attachments. The ecological significance of these immediate hyphal bridges for achlorophyllous plants is discussed. The morphological and anatomical features of V. aphylla roots and its Paris-type arbuscular mycorrhiza (AM) appear to be transitional between those of V. truncata and V. tenella. A hypothetical evolutionary progression of AM and its significance for the development of mycoheterotrophy is proposed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050260
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Biotite and microcline as potassium sources in ectomycorrhizal and non-mycorrhizal Pinus sylvestris seedlings (1999)
    Springer
    Mycorrhiza 9 (1999), S. 25-32 
    Details
    ISSN: 1432-1890
    Keywords: Key words Ectomycorrhiza ; Feldspar ; Mica ; Paxillus ; Pine ; Suillus ; Weathering
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The aim of this study was to investigate the role of plants colonised by two ectomycorrhizal fungi, Paxillus involutus and Suillus variegatus, in mobilising potassium (K) from biotite and microcline, two minerals common in acid to medium-acid bedrock. This was carried out in a 33-week pot study with seedlings of Pinus sylvestris growing in symbiosis with the fungi, where no K was added or where K was added in the form of biotite or microcline. The mineral additions were similar to those found in natural soils. All seedlings, including non-mycorrhizal, were able to access the K in biotite, leading to stimulated growth and K uptake relative to controls. Microcline addition induced growth depression in all seedlings except those colonised by P. involutus, which were stimulated. The soil solution from S. variegatus-colonised seedlings grown with biotite had higher concentrations of citric and oxalic acid. Citric acid concentration was positively correlated to the fungal biomass (ergosterol) in the soil, as well as to the foliar K in S. variegatus-colonised seedlings. Seedlings growing without K addition had low K concentrations in the shoot. Magnesium (Mg) concentrations were enhanced in seedlings with severe K shortage, indicating that Mg can substitute for K, while calcium concentrations did not vary significantly.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050259
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    The carbon origin of arbuscular mycorrhizal fungi estimated from δ13C values of individual spores (1999)
    Springer
    Mycorrhiza 9 (1999), S. 41-47 
    Details
    ISSN: 1432-1890
    Keywords: Key words Arbuscular mycorrhizal fungi ; Carbon origin ; δ13C ; C3 plant ; C4 plant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The origin of carbon in the spores of arbuscular mycorrhizal (AM) fungi was quantified based on their obligate symbiosis with C3 and C4 plants showing clearly different δ13C values. The δ13C values of individual spores of the AM fungus Gigaspora margarita were analyzed. In monoculture pots of a C3 or a C4 plant species, spore δ13C values were ca. 3.5‰ lower than those of host roots. In coculture pots of a C3 and a C4 plant species, spore δ13C values varied between those of the roots of C3 and C4 plants, and increased linearly from the C3 to the proximity of the C4 plant (P〈0.01). This reflects the higher δ13C values in C4 plants than in C3 plants. Thus the carbon origin of G. margarita spores changed with growth state and combination of host plants. In the presence of fresh plant residue instead of living host plants, spore δ13C values did not vary with distance from the residue. This finding supports the current view that AM fungi are obligate symbionts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050261
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Root respiratory quotient and nitrate uptake in hydroponically grown non-mycorrhizal and mycorrhizal wheat (1999)
    Springer
    Mycorrhiza 9 (1999), S. 57-60 
    Details
    ISSN: 1432-1890
    Keywords: Key words Glomus mosseae ; Hydroponics ; Nitrate uptake ; Root respiration ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Oxygen and CO2 fluxes were measured in hydroponically grown mycorrhizal and non-mycorrhizal Triticum aestivum L. cv. Hano roots. The NO3 – uptake of the plants was used to estimate the amount of root respiration attributable to ion uptake. Plants were grown at 4 mM N and 10 μM P, where a total and viable mycorrhizal root colonisation of 48% and 18%, respectively, by Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe (BEG 107) was observed. The O2 consumption and NO3 – uptake rates were similar and the CO2 release was higher in mycorrhizal than in non-mycorrhizal wheat. This resulted in a significantly higher respiratory quotient (RQ, mol CO2 mol–1 O2) in mycorrhizal (1.27±0.13) than in non-mycorrhizal (0.79±0.05) wheat. As the biomass and N and P concentrations in mycorrhizal and non-mycorrhizal wheat were the same, the higher RQ resulted from the mycorrhizal colonisation and not differences in nutrition per se.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050263
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    Suppression of ectomycorrhizae on canopy tree seedlings in Rhododendron maximum L. (Ericaceae) thickets in the southern Appalachians (1999)
    Springer
    Mycorrhiza 9 (1999), S. 49-56 
    Details
    ISSN: 1432-1890
    Keywords: Key words Eastern Hemlock ; Ectomycorrhiza ; Mycorrhizal ; colonization ; Northern red oak ; Cenococcum geophilum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Thickets of Rhododendron maximum (Ericaceae) (Rm) in the southern Appalachians severely limit regeneration of hardwood and coniferous seedlings. Experimental blocks were established in and out of Rm thickets in a mature, mixed hardwood/conifer forest in Macon County, N.C. Litter and organic layer substrates were removed, composited and redistributed among plots within the blocks (except for control plots). Seedlings of northern red oak (Quercus rubra) and eastern hemlock (Tsuga canadensis) were planted in the plots and harvested at the end of the first and second growing seasons. Litter manipulation had no effect on total mycorrhizal colonization, but the distribution of Cenococcum geophilum mycorrhizae was altered. After the first year, percent mycorrhizal colonization of hemlocks not in Rm thickets (62%) was at least three times higher than in Rm thickets (19%), and the ramification index (no. of mycorrhizae cm–1) had increased by more than a factor of four (2.83 versus 0.61). In addition, colonization of 1-year-old hemlocks by C. geophilum was significantly higher within blocks with (10.4%) than without (4.6%) Rm. Differences in mycorrhizal colonization, ramification indices and colonization by C. geophilum were absent or less pronounced on 2-year-old hemlocks and 1- and 2-year-old oak seedlings. The biomasses of first year oak roots and shoots and second year shoots were 50% less in Rm thickets. Biomasses of first year hemlock roots and second year shoots were also reduced. Mycorrhizal parameters were correlated with some growth parameters only for hemlock seedlings, but did not explain most of the variation observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050262
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Referee acknowledgement (1999)
    Springer
    Mycorrhiza 8 (1999), S. 339-339 
    Details
    ISSN: 1432-1890
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050256
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Surface-sterilization of Glomus mosseae sporocarps for studying endomycorrhization in vitro (1999)
    Springer
    Mycorrhiza 9 (1999), S. 65-68 
    Details
    ISSN: 1432-1890
    Keywords: Key words Glomus mosseae ; Sporocarps ; Surface sterilization ; Germination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The effects of sterilization time, sterilizing agents (ethanol, Chloramine T, calcium hypochlorite) and antibiotics (streptomycin and gentamycin) on Glomus mosseae (BEG 12) sporocarp germination and contamination were evaluated. Incubation for 10 s in 96 % ethanol, followed by 10 min in a solution of 2% Chloramine T, 0.02% streptomycin, 0.01% gentamycin and Tween 20, and then 6 min in 6% calcium hypochlorite greatly reduced fungal and bacterial contamination from sporocarps and caused little change in germination rate in water agar medium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050001
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Field performance in northern Spain of Douglas-fir seedlings Inoculated with ectomycorrhizal fungi (1999)
    Springer
    Mycorrhiza 9 (1999), S. 77-84 
    Details
    ISSN: 1432-1890
    Keywords: Key words Pseudotsuga menziesii ; Laccaria bicolor ; Melanogaster ambiguus ; Rhizopogon subareolatus ; Rhizopogon colossus ; Reforestation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Experimental plantations were established in northern Spain to determine the effects of different ectomycorrhizal fungi on growth and survival of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) under field conditions. Douglas-fir seedlings were inoculated with Laccaria bicolor S238 mycelia in two bareroot nurseries in central France or with spore suspensions of three hypogeous ectomycorrhizal species: Melanogaster ambiguus, Rhizopogon colossus and R. subareolatus, in a Spanish containerised nursery. The effects of ectomycorrhizal inoculation on plant survival after outplanting were limited, being only significant at the Guipuzkoan (Spain) site, when plants inoculated with L. bicolor S238 were compared to non-inoculated plants grown in non-fumigated soil. L. bicolor S238 had a significant effect on plant growth during the phase of bareroot nursery growth and this difference was maintained after field outplanting. Nursery inoculations with M. ambiguus, R. colossus and R. subareolatus improved plant growth during the first 2 and 3 years after field outplanting. The positive effects of the inoculation treatment on seedling height, root collar diameter and stem volume persisted after 5 years of field growth. Inoculation with these ectomycorrhizal fungi may improve the field performance of Douglas-fir seedlings in northern Spain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050003
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Genes involved in resistance to powdery mildew in barley differentially modulate root colonization by the mycorrhizal fungus Glomus mosseae (1999)
    Springer
    Mycorrhiza 9 (1999), S. 237-240 
    Details
    ISSN: 1432-1890
    Keywords: Key words Barley ; Glomus mosseae ; Powdery mildew ; Non-race-specific resistance ; Race-specific resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Arbuscular mycorrhizal fungi (AMF) and Erysiphe graminis are obligate biotrophic fungi with different outcomes in their interaction with plants, different targeted host tissues, but similar patterns of development and infection processes. These similarities raise the question of whether the two types of biotrophic fungal infections have common features in their regulation. To investigate this question, we compared a number of Ror and Rar barley mutants susceptible to E.graminis f. sp. hordei, as well as their resistant progenitors, for susceptibility to infection by the AMF Glomus mosseae. The two powdery mildew-resistant lines BC Ingrid and Sultan presented a similar reduction in G. mosseae development within roots when compared to the wildtype cultivar Ingrid, indicating a systemic effect of the altered genes in the plant. Ror and Rar mutants, in which susceptibility to powdery mildew is restored, showed increased resistance to AM fungal development in their roots when compared to their progenitors, which suggests that corresponding mutations must have affected genes which differentially modulate symbiotic and pathogenic biotrophic plant-fungus interactions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050273
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Movements and diving behavior of weaned Weddell seal (Leptonychotes weddellii ) pups (1999)
    Springer
    Polar biology 21 (1999), S. 23-36 
    Details
    ISSN: 1432-2056
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Between 1993 and 1995, the diving behavior and movement patterns of 23 weaned Weddell seal pups (Leptonychotes weddellii) were tracked in the Ross Sea. Antarctica, using satellite-linked time-depth recorders. Regression analyses revealed that for seals of between 8 and 27 weeks old, age was poorly correlated with the dive depth, duration, or frequency. However, changes in dive parameters suggested that Weddell seal pups were attempting to maximize dive time, but the manner in which this was done depended on age and time of day. Movement patterns indicated that most Weddell seal pups left their natal area by the end of February, and traveled north along the Antarctic continent coastline. Several individuals returned to McMurdo Sound, but others were last located more than 400 km from McMurdo. Routes followed suggest that pups can use the pack ice habitat, but prefer to remain closer to the coastline than do adults.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003000050329
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Erratum: Polar Biol (1998) 20: 189–197 (1999)
    Springer
    Polar biology 21 (1999), S. 64-64 
    Details
    ISSN: 1432-2056
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003000050334
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Lipids and trophic interactions of ice fauna and pelagic zooplankton in the marginal ice zone of the Barents Sea (1999)
    Springer
    Polar biology 21 (1999), S. 65-70 
    Details
    ISSN: 1432-2056
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Gammarus wilkitzkii, Apherusa glacialis, Onismus nanseni, Onismus glacialis, Boreogadus saida, Parathemisto libellula and Calanus hyperboreus, collected in late June in the Barents Sea marginal ice zone, contained substantial levels (28–51% of the dry mass) of total lipid, the highest levels (51% and 41% respectively) being in  A. glacialis and  C. hyperboreus. Neutral lipids were present in greater amounts than polar lipids in all species. Triacylglycerols were major neutral lipids in A. glacialis, G. wilkitzkii and O. nanseni; triacylglycerols and wax esters were present in similar amounts in O. glacialis; higher levels of wax esters than triacylglycerols occurred in P. libellula; wax esters greatly exceeded triacylglycerols in C. hyperboreus, the opposite being true for B. saida. Diatom fatty acid markers were prominent in the triacylglycerols of G. wilkitzkii, O. nanseni, O. glacialis and, particularly, of  A. glacialis; 20:1(n-9) and 22:1(n-11) moieties were abundant in wax esters of G. wilkitzkii, O. nanseni, O. glacialis, P. libellula and  C. hyperboreus, and in triacylglycerols of B. saida. We deduce that  A. glacialis feeds mainly on ice algae and phytodetritus, G. wilkitzkii and the Onismus spp. feed on calanoid copepods as well as ice algae, whereas P. libellula and especially B. saida feed extensively on calanoid copepods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003000050335
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Autotrophic carbon assimilation and biomass from size-fractionated phytoplankton in the surface waters across the subtropical frontal zone (Indian Ocean) (1999)
    Springer
    Polar biology 21 (1999), S. 90-96 
    Details
    ISSN: 1432-2056
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The composition of the phytoplanktonic communities in the surface waters of the La Reunion-Kerguelen transect (from 38°36S to 46°33S) has been investigated under spring conditions (Antarès 3 cruise, France-JGOFS, 28 September–8 November, 1995). The study, conducted at six stations in the subtropical frontal zone, involved size fractionations (threshold: 2 μm). The large variations in the overall biomass and autotrophic carbon fixation, calculated via Rubisco activity measurements and expressed respectively in terms of μg chlorophyll (a + b + c) per liter and nmol fixed carbon dioxide per liter and per hour, were attributable only to phytoplanktonic cells of 〉2 μm, with a peak observed in the frontal zone. The picophytoplankton (〈2 μm) biomass remained constant throughout the transect, but the evolution of the species composition of the picophytoplanktonic population, as calculated from flow cytometry measurements through this frontal zone, changed. This study provides evidence, for the first time in this area, of the disappearance of prochlorophytes from the south of the frontal zone (42–47°S). Picoeukaryotes (〈2 μm) and cyanobacteria populations, resolved by flow cytometry, were present all along the transect. However, their abundance decreased southward up to the quasi-disappearance of cyanobacteria at the southernmost station (52°S) that is characteristic of antarctic waters. The presence of prochlorophytes that is exclusive to the subtropical surface waters, and the low carbon fixation activity associated with these waters, may be linked to the specific hydrological features encountered. In contrast, the marked reduction in the cyanobacteria and the abundance of picoeukaryotes along the north-south transect is more likely to be a result of the reduction in temperature through the frontal zone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003000050339
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    First census of breeding seabirds between Cap Bienvenue (Terre Adélie) and Moyes Islands (King George V Land), Antarctica: new records for Antarctic seabird populations (1999)
    Springer
    Polar biology 21 (1999), S. 146-150 
    Details
    ISSN: 1432-2056
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Breeding population sizes of penguins, fulmarine etrels and skuas were estimated for the first time on a major part of the Terre Adélie coast and a section of the King George V Land coast during the 1997/1998 austral summer. We counted 106,400 breeding pairs and 12,400 Adélie penguin (Pygoscelis adeliae) chicks by direct counts, and 6960 breeding pairs from aerial photographs. Minimum breeding populations for other species are (direct counts): Antarctic fulmar (Fulmarus glacialoides) 6861 pairs, Antarctic petrel (Thalassoica antarctica) 4574 pairs, cape petrel (Daption capense) 194 pairs, snow petrel (Pagodroma nivea) 767 pairs, south polar skua (Catharacta maccormicki) 129 pairs and subantarctic skua (Catharacta lonnbergi) 1 breeding bird. We discovered 29 new seabird breeding locations in King George V Land, including 6 Antarctic fulmar, 4 Antarctic petrel, 3 cape petrel, 6 snow petrel and 10 south polar skua colonies. The largest colonies found contained up to 4205 breeding pairs of Antarctic fulmars. Population sizes of all species obtained in this study are higher than those found during previous partial surveys. Although these differences are in great part due to differences in survey methods, they also reflect real population changes. Our minimum population sizes obtained for a small portion of the Antarctic coast (〈2%) suggest an underestimation of the estimated world breeding populations for several species of Antarctic seabirds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003000050345
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...