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  • 1
    Digitale Medien
    Digitale Medien
    Selektive Partnerwahl der Aaskrähe (Corvus corone) in der Hybridisierungszone von Rabenkrähe (C. c. corone) und Nebelkrähe (C. c. cornix) (1998)
    Springer
    Journal of ornithology 139 (1998), S. 173-177 
    Details
    ISSN: 1439-0361
    Schlagwort(e): mate choice ; taxonomy ; phenotypic hybrids ; fitness ; decision rule
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die als Unterarten klassifizierten europäischen Formen der Aaskrähe, Rabenkrähe und Nebelkrähe, besiedeln verschiedene, aneinandergrenzende Verbreitungsgebiete und hybridisieren in der Kontaktzone. Die Nachkommen von Mischpaaren sind fruchtbar und können sowohl mit anderen Hybriden als auch mit Raben- und Nebelkrähen erfolgreich brüten. Trotzdem kommt es zu keiner völligen Vermischung der Formen und/oder Verlagerung der Verbreitungsgebiete. Vor diesem Hintergrund untersuchten wir die Partnerwahl von Aaskrähen in der Hybridisierungszone auf der nordfriesischen Insel Amrum und stellten fest, daß Partner gleichen Phänotyps häufiger miteinander verpaart waren, als stochastisch zu erwarten gewesen wäre. Unsere Daten bestätigen vergleichbare Studien aus Hybridisierungszonen in Italien und Sibirien. Wir schließen daraus, daß phänotypisch selektive Partnerwahl bei der Aaskrähe ein allgemeines Phänomen sein könnte und diskutieren, warum dieses Verhalten anfitness-relevante Parameter gekoppelt sein sollte. Um welche es sich dabei handeln könnte, wurde bisher nicht hinreichend untersucht und muß deshalb offen bleiben.
    Notizen: Summary Carrion Crow and Hooded Crow are regarded as subspecies of the Crow. They show frequent hybridisation along the adjacent borders of their distribution. Mixed pairs produce fertile offspring which are able to breed successfully with both hybrids and mates of either phenotype. However, hybridisation does not lead to phenotypic changes of Carrion and Hooded Crows in general nor in their distinct distribution. We studied the mating behaviour of Crows in the hybrid zone on the Island of Amrum (Schleswig-Holstein, Germany) and found evidence that Crows may prefer mates of the same phenotype. Our data confirm previous studies which reported assortative mating with respect to plumage coloration from hybrid zones in Italy and Siberia. We discuss why this behaviour should be related tofitness traits which in our opinion have not yet been studied adequately nor identified.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01651226
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  • 2
    Digitale Medien
    Digitale Medien
    Mitochondrial DNA analysis of Exophiala jeanselmei and Exophiala dermatitidis (1990)
    Springer
    Mycopathologia 110 (1990), S. 107-112 
    Details
    ISSN: 1573-0832
    Schlagwort(e): DNA ; Exophiala dermatitidis ; Exophiala gougerotii ; Exophiala jeanselmei ; mitochondria ; restriction profiles ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Mitochondrial DNA (mtDNA) analysis with Hae III, Hind. III and Msp I was performed in 45 Exophiala jeanselmei strains (30 Phialophora jeanselmei and 15 Phialophora gougerotii strains) and 31 Exophiala dermatitidis strains. The results were as follows, 1) P. jeanselmei and P. gougerotii are identical, 2) E. jeanselmei is classified into 18 types based on restriction profiles, 3) two strains of E. jeanselmei CBS 577.76 and CBS 578.76 are identified as E. dermatitidis, 4) E. dermatitidis has no intraspecific variation and is definitely distinct from E. jeanselmei, 5) E. jeanselmei is suggested to be a complex organism because of extensive mtDNA polymorphism.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00446999
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  • 3
    Digitale Medien
    Digitale Medien
    Numerical taxonomy of fluorescent Pseudomonas associated with tomato roots (1990)
    Springer
    Antonie van Leeuwenhoek 57 (1990), S. 223-236 
    Details
    ISSN: 1572-9699
    Schlagwort(e): fluorescent Pseudomonas ; root associated ; siderophores ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The phenetic taxonomy of 110 fluorescent bacterial strains, isolated from the roots of tomatoes and other plants was numerically studied through 97 features including 69 assimilation tests. Thirty-two reference strains of various Pseudomonas spp. were additionally included. The strains clustered into 16 clusters at the 74% similarity level when using Jaccard similarity coefficients. Almost all field strains belonged to the P. fluorescens/P. putida-complex while none clustered with P. syringae and allied bacteria. The biovar II branch, as well as the newly described biovar VI of P. fluorescens, made up 55% and 20% respectively, of the field strains; two % were allocated to P. fluorescens biovar I and three % to biovar IV. Eleven % of the root associated strains were designated P. putida; six strains were biovar A, three strains biovar B while four strains could not be referred to any known biovar. The continuum within the P. fluorescens/P. putida-complex as well as the taxonomic status of the six biovars of P. fluorescens and the three biovars of P. putida are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00400154
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  • 4
    Digitale Medien
    Digitale Medien
    Zygozyma smithiae sp.n. (Lipomycetaceae), a new ambrosia yeast from Southern Africa (1990)
    Springer
    Antonie van Leeuwenhoek 58 (1990), S. 95-98 
    Details
    ISSN: 1572-9699
    Schlagwort(e): Zygozyma smithiae ; Lipomycetaceae ; ambrosia yeasts ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A new species of the genus Zygozyma, Z. smithiae, was recovered from frass of the ambrosia beetle, Crossotarsus externedentatus in Northern Natal. A description of the new species and key to the genus are given.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00422723
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  • 5
    Digitale Medien
    Digitale Medien
    Arxula gen. nov. (Candidaceae), a new anamorphic, arthroconidial yeast genus (1990)
    Springer
    Antonie van Leeuwenhoek 57 (1990), S. 59-61 
    Details
    ISSN: 1572-9699
    Schlagwort(e): Arxula ; Candidaceae ; yeasts ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The new genus Arxula is proposed for the classification of xerotolerant, ascomycetous, anamorphic, arthroconidial yeasts. The genus is considered to be of endomycetaceous affinity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00400338
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  • 6
    Digitale Medien
    Digitale Medien
    Kurtzmanomyces tardus sp. nov., a new anamorphic yeast species of basidiomycetous affinity (1990)
    Springer
    Antonie van Leeuwenhoek 58 (1990), S. 129-135 
    Details
    ISSN: 1572-9699
    Schlagwort(e): basidiomycetous yeasts ; Kurtzmanomyces tardus ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A new yeast species of basidiomycetous affinity Kurtzmanomyces tardus was isolated from contaminated demineralized water. It differs from K. nectairii, the only other Kurtzmanomyces species so far described, in its carbon assimilation pattern and low DNA-DNA homology (2.3%±2.1).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00422729
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  • 7
    Digitale Medien
    Digitale Medien
    Dipodascus capitatus, Dipodascus spicifer and Geotrichum clavatum: Genomic characterization (1998)
    Springer
    Antonie van Leeuwenhoek 74 (1998), S. 229-235 
    Details
    ISSN: 1572-9699
    Schlagwort(e): Dipodascus capitatus ; D.spicifer ; Geotrichum clavatum ; yeast ; taxonomy ; DNA heterogeneity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The G+C contents of 25 strains of Dipodascus capitatus, Dipodascus spicifer and Geotrichum clavatum were found to be heterogeneous on basis of derivative graphs of the melting profiles. Strains showing similar derivative graphs of the melting curve exhibited high levels of DNA homology (80-100%); strains showing dissimilar derivative graphs exhibited low levels of DNA homology (5 to 45%). Being considered separate taxa on basis of these parameters, D. capitatus, D. spicifer and G. clavatum could be identified by a combination of the key characteristics growth on xylose, cellobiose, salicin and arbutin.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1001762024710
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  • 8
    Digitale Medien
    Digitale Medien
    Identification of Taxa in the Genus shape Beta using ITS1 Sequence Information (1998)
    Springer
    Plant molecular biology reporter 16 (1998), S. 147-155 
    Details
    ISSN: 1572-9818
    Schlagwort(e): allele-specific PCR ; Beta ; ITS1 ; plant identification ; rDNA ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Sequence variation in the ITS1 locus of the nuclear ribosomal DNA in beets has previously been used to reconstruct phylogeny of the species in the genus Beta. We have developed protocols that allow the identification of Beta taxa by use of taxon-specific primers. Beta sections, species and subspecies can be identified. Differences within the ITS1 region of a single base can be exploited for species identification. The results from this study not only provide effective methods for wild beet identification, but also indicate the potential use of the techniques in other crops.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1007416817736
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  • 9
    Digitale Medien
    Digitale Medien
    The taxonomic impediment in orthopteran research and conservation (1998)
    Springer
    Journal of insect conservation 2 (1998), S. 151-159 
    Details
    ISSN: 1572-9753
    Schlagwort(e): Orthoptera ; biodiversity ; taxonomy ; conservation.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Wissenschaftskunde und Wissenschaftsorganisation, Hochschul- und Universitätswesen, Museumswissenschaft
    Notizen: Abstract It is estimated that only 10–15% of the world's insect fauna has been described and named. Efforts to inventory insect biodiversity are hampered by this taxonomic impediment, which is compounded by the logistical problems of an insufficient taxonomic workforce and their remote location in museums thousands of miles from the areas of highest biodiversity. Compared to most other invertebrate groups however, the taxonomic impediment is relatively benign in the order Orthoptera. This is a small to medium-sized order (approximately 20 000 described species) which is well known taxonomically, owing to the group's agricultural importance worldwide. Furthermore, orthopteran taxonomists are now fortunate to have a published up-to-date catalogue of all known species, which has just become accessible as a regularly updated database on the World Wide Web. Whilst new information technology, in the form of e-mail networks, World Wide Web sites and CD-ROM information archives, is already enhancing communication between specialists and helping to reduce the logistical problems of documenting orthopteran biodiversity, a major reinvestment in basic taxonomic research is needed if we are to reduce the existing taxonomic impediment significantly. There is general agreement that an internationally coordinated approach will be necessary and priorities must be set to tackle the biodiversity/systematics crisis. In the future, the Orthoptera can make an important contribution to invertebrate faunal surveys and have potential as an indicator taxon. Furthermore, the Orthoptera Species File establishes a taxonomic framework which could be readily enlarged to include geographic data and phenology of species from existing museum specimens.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009633811789
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  • 10
    Digitale Medien
    Digitale Medien
    Field measurements of gas exchange in Avicennia marina and Bruguiera gymnorrhiza (1998)
    Springer
    Mangroves and salt marshes 2 (1998), S. 99-107 
    Details
    ISSN: 1572-977X
    Schlagwort(e): conductance ; mangrove ; photosynthesis ; productivity ; water potential
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Diurnal gas exchange characteristics were measured simultaneously in two mangrove species, Avicennia marina and Bruguiera gymnorrhiza, over 7 d in summer (February–March), to compare their productivity. The study was undertaken in the Beachwood Mangroves Nature Reserve, Durban, South Africa, using fully expanded leaves of young and mature trees at the top of the canopy. Gas exchange was strongly influenced by photosynthetic photon flux density (PPFD), leaf temperature and the accompanying leaf to air vapour pressure deficit (Δ w). Carbon dioxide exchange was saturated at a PPFD of about 600 μmol m-2s-1 in B. gymnorrhiza compared to 800 μmol m-2s-1 in A. marina. Maximal CO2 exchange occurred between 12h00 and 14h00 and was consistently greater in A. marina (8.8 μmol m-2s-1) than in B. gymnorrhiza (5.3 mu;mol m-2s-1). Mean internal CO2 concentrations ( ci) were 260 μl l-1 in A. marina and 252 μl l-1 in B. gymnorrhiza. Photorespiratory activity was 32% in A. marina and 30% in B. gymnorrhiza. Mean water use efficiency (WUE) was 8.0 μmol mmol-1 in A. marina and 10.6 μmol mmol-1 in B. gymnorrhiza. Diurnal leaf water potentials ranged from –0.8 to –3.5 MPa and were generally lower in A. marina.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009939523164
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  • 11
    Digitale Medien
    Digitale Medien
    Mangrove forest productivity and biomass accumulation in Hinchinbrook Channel, Australia (1998)
    Springer
    Mangroves and salt marshes 2 (1998), S. 191-198 
    Details
    ISSN: 1572-977X
    Schlagwort(e): canopy ; Hinchinbrook ; leaf area index ; mangrove ; photosynthesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Data on stand structure and rates of photosynthesis were used to estimate net canopy carbon fixation and carbon accumulation as living biomass in mangrove forests in Hinchinbrook Channel, Australia. Total annual canopy net carbon fixation was estimated to be about 29 t C ha−1 yr−1. This equates to about 204,000 t C yr−1 for all mangrove forests in Hinchinbrook Channel. Of this, only about 12% was stored as living plant biomass. Although it is not yet possible to present a robust carbon balance for mangrove trees, the remainder is presumably lost through plant respiration, litter fall, root turnover and exudation of organic compounds from roots.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009979610871
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  • 12
    Digitale Medien
    Digitale Medien
    Influence of Taxonomy, Ecology, and Seasonality in River Stage on Fish Contamination Risks in Floodplain Swamps of the Lower Mississippi River (1998)
    Springer
    Ecotoxicology 7 (1998), S. 325-334 
    Details
    ISSN: 1573-3017
    Schlagwort(e): contamination risks ; fish ; Mississippi River ; ecological factors ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Energietechnik
    Notizen: Abstract We compared contamination levels in fish from contaminated and uncontaminated floodplain swamps of the lower Mississippi River to assess differences in contamination risks between swamps, across different taxonomic and ecological groupings of fishes within and between swamps, and with seasonality in river stage. Fish tissue levels of inorganic contaminants were substantially lower than environmental levels in both swamps, suggesting either that fish were not uptaking these contaminants, or they were effectively eliminating the contaminants from their bodies. Tissue levels of organic contaminants were high relative to environmental levels, suggesting that these contaminants were bioaccumulating. Organic contaminants were significantly higher in fish from the contaminated swamp (Devil's Swamp) than in fish from a reference swamp up river (Tunica Swamp). Because the organic contaminants were largely confined to sediments, we expected bottom-oriented fishes to have higher concentrations than pelagic fishes. Assuming that uptake was primarily through the food chain, we expected top predators to exhibit higher concentrations than low-level consumers. We also expected year- round swamp residents to exhibit higher accumulations than more transitory users of backswamp habitat. However, organic contaminant levels did not differ in the directions expected for any of these groupings. We did observe differences in organic contaminant levels within and between swamps for different taxonomic groupings of fishes (species and genera). Some taxa occupying low to middle positions in the food web (e.g., gizzard shad, Lepomis spp.) exhibited higher concentrations than taxa near the top of the food web. Within Devil's Swamp, organic contaminant levels were significantly higher at low river stage, when fish were confined to the swamp, than at high river stage, when fish were free to move between the river and the swamp. We caught more species and more fish per unit effort in Devil's Swamp than in Tunica Swamp, contrary to expectations if contaminants in the former were negatively impacting population and community structure. Species richness differences between swamps were a consequence of catch differences, with higher catch corresponding to inclusion of more rare species. The lower catch in Tunica Swamp may have resulted from physical modifications of its waterways to support agriculture and hunting. The results of this study underscore the importance in factoring information on the taxonomy and ecology of organisms, and seasonal changes in environmental conditions, into assessments of contamination risks.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008811713427
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  • 13
    Digitale Medien
    Digitale Medien
    Ground cover, photosynthetic rate and tuber yield of potato (Solanum tuberosum L.) crops from seed tubers with different physiological age modified by foliar applications of plant growth regulators (1998)
    Springer
    Potato research 41 (1998), S. 175-185 
    Details
    ISSN: 1871-4528
    Schlagwort(e): benzylaminopurine ; gibberellic acid ; senescence ; photosynthesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The modifying effects of applying the plant growth regulators (PGRs) benzylaminopurine (BAP), gibberellic acid (GA3) and BAP+GA3 on physiological age were studied. Two experiments with two cultivars, differing in rate of physiological ageing (medium-early Pampeana, medium-late Huinkul) and two storage systems were performed during 1988/89 and 1989/90 in two different potato areas of Argentina. In both seasons seed tubers stored in heaps reached an advanced physiological age at planting, compared with tubers from the cold store. Seed tubers of cv. Pampeana were older than those of Huinkul. compared with control crops, those sprayed with BAP maintained ground cover and photosynthesis for longer, and those sprayed with GA3 for a shorter period. Consequently tuber yield was decreased by GA3 in 1988/89, but in 1989/90 all crops treated with PGRs outyielded the control. BAP could overcome effects of advanced physiological age on crop senescence and tuber yield.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02358440
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  • 14
    Digitale Medien
    Digitale Medien
    Morphology and molecular phylogeny ofTretopileus sphaerophorus, a synnematous hyphomycete with basidiomycetous affinities (1998)
    Springer
    Mycoscience 39 (1998), S. 21-30 
    Details
    ISSN: 1618-2545
    Schlagwort(e): Aphyllophorales ; ribosomalDNA ; synnematous hyphomycete ; taxonomy ; Tretopileus sphaerophorus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Tretopileus sphaerophorus, a synnematous hyphomycete with basidiomycetous affinities was newly isolated from the decaying petiole and peduncle ofCocos nucifera collected in Depok, Indonesia. The species produced first a bulbil as a propagule on the top of a synnema. After the bulbil had fallen, the synnema proliferated about seven times to produce new bulbils, each time making conspicuous nodes at the upper part. By careful morphological observation, clamp connections were confirmed on the hyphae in the specimens and culture. In culture, each hyphal cell with or without a clamp was found to be dikaryotic by DAPI nuclear staining. Germination of the bulbils occurred first from projecting hyphal tips on their upper surface, which have been treated as germ pores. The inner structure of the bulbils, the hyaline mucus of the bulbils, and conidium-like hyphal fragments were also examined. Phylogenetically,T. sphaerophorus was inferred to be related to the Aphyllophorales based on the nuclear encoded small subunit (18S) rDNA using the homology search system (FASTA) and the neighbour-joining method.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02461574
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  • 15
    Digitale Medien
    Digitale Medien
    The order phyllachorales: Taxonomic review (1998)
    Springer
    Mycoscience 39 (1998), S. 97-104 
    Details
    ISSN: 1618-2545
    Schlagwort(e): Loculoascomycetes ; phyllachoraceae ; phyllachorales ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The order Phyllachorales contains ascomycetous fungi of considerable economic importance. The group is represented mostly by foliar parasites which produce perithecia under a clypeus, inside a stroma, or do not produce any stromatic tissue. A major taxonomic problem with this order is the lack of reliable morphological characters that clearly delimit the entire group. The main purpose of this review is to provide a clear picture of the taxonomic relationships of the order Phyllachorales, along with a key to the most important genera in the family Phyllachoraceae.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02461586
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  • 16
    Digitale Medien
    Digitale Medien
    On some species ofMycogloea (1998)
    Springer
    Mycoscience 39 (1998), S. 31-36 
    Details
    ISSN: 1618-2545
    Schlagwort(e): Mycogloea ; Platygloea ; Platygloeaceae ; Platygloeales ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Three new species ofMycogloea are described and illustrated; they are:M. amethystina from Canada,M. nipponica, from Japan, andM. bullata from Thailand.Mycogloea tahitiensis is reported from Japan and additional undescribed taxa in the genus are briefly noted. Some characteristics of the genus are discussed, and a key is provided for six species recognized at this time.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02461575
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  • 17
    Digitale Medien
    Digitale Medien
    Phylogenetic relationships betweenVicia faba (Fabaceae) and related species inferred from chloroplasttrnL sequences (1998)
    Springer
    Plant systematics and evolution 212 (1998), S. 247-259 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Fabaceae ; Vicia faba ; trnL intron ; PCR-sequencing ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The chloroplasttrnL intron from 46 differentVicia accessions, representing five of the nine sections of the genusVicia subg.Vicia sensuMaxted (1991a) were amplified by the Polymerase Chain Reaction (PCR) using oligonucleotide primers homologous to conserved regions intrnL. The products fell into two distinct groups; those of approximately 250 nt and those of around 450 nt in length. Of these, products from 17 differentVicia species were cloned and their nucleotide sequences determined. Multiple alignments were assembled and phylogenetic trees constructed by the weighted least-squares distance method. ALathyrus latifolius trnL intron sequence was used as an outgroup. The resulting trees clearly group and separate the sectt.Narbonensis, Bithynica andFaba species but were less able to distinguish species from sectt.Hypechusa andPeregrinae. Based on these sequence data,V. faba appears to be more distant from sect.Narbonensis than sectt.Hypechusa andPeregrinae. The results are in general agreement with a recent treatment ofVicia subg.Vicia (Maxted 1993) and lend further support to placingV. faba in the monospecific sect.Faba.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01089741
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  • 18
    Digitale Medien
    Digitale Medien
    Isoenzyme variation in the wild relatives ofVicia faba (Fabaceae) (1998)
    Springer
    Plant systematics and evolution 213 (1998), S. 173-186 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Fabaceae ; Vicia ; sect.Bithynicae ; sect.Narbonensis ; Allozymes ; genetic diversity ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Electrophoretic analysis of five enzyme systems, LAP, PGI, SKDH, SOD and 6-PGDH, among 102Vicia accessions representingV. bithynica and seven species of theV. narbonensis complex, namelyV. eristalioides, V. kalakhensis, V. johannis, V. galilaea, V. serratifolia, V. narbonensis andV. hyaeniscyamus, has been performed. The recorded variation was tentatively assigned to 41 allelic genes at eight loci; intraspecific variation was observed in all species except forV. eristalioides. The results obtained were compared with the corresponding data reported earlier forV. faba. Hierarchical grouping of the investigated taxa, includingV. faba, was based onNei's genetic identities calculated from the allozyme frequency data.Vicia faba andV. bithynica were shown to be most distantly related to one another and to the remaining species investigated.Vicia serratifolia appeared to be a peripheral member of theV. narbonensis complex. The results are discussed with reference to genetic diversity and taxonomic relationships of the species under study.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00985198
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  • 19
    Digitale Medien
    Digitale Medien
    Effect of thiobencarb on growth and photosynthesis of the soil alga Protosiphon botryoides (Chlorophyta) (1998)
    Springer
    Journal of applied phycology 10 (1998), S. 547-554 
    Details
    ISSN: 1573-5176
    Schlagwort(e): herbicide ; green alga ; growth ; nutrients ; photosynthesis ; it Protosiphon botryoides ; respiration ; Thiobencarb
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The effects of the herbicide thiobencarb (Saturn) were tested on the growth and physiology of the chlorophyte Protosiphon botryoides isolated from an Egyptian paddy. Assays were conducted using 16-day batch cultures. Chlorophyll and dry weight biomass yields were significantly reduced at 2–3 mg L-1 thiobencarb, and dark respiration increased and protein decreased significantly at 3 mg L-1. Reductions in exponential specific growth rate (μ) were generally small, but in some cases significant. Thiobencarb also slightly, but significantly, reduced the 77 K fluorescence parameter Fv/Fm, an indicator of maximum photosynthetic efficiency. No consistent dose-dependent changes occurred in chlorophyll per unit dry weight, total carbohydrate or gross photosynthetic capacity. Whereas half of the added thiobencarb was recovered from control (uninoculated) medium, it was largely absent from cells and culture medium after sixteen days, indicating biodegradation by the alga or associated bacteria. P. botryoides recovered fully within sixteen days following subculture in thiobencarb-free medium. Independently varying phosphate and nitrate nine-fold had no clear effect on the sensitivity of P. botryoides to thiobencarb.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008092826338
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  • 20
    Digitale Medien
    Digitale Medien
    Effects of increased atmospheric CO2 and N supply on photosynthesis, growth and cell composition of the cyanobacterium Spirulina platensis (Arthrospira) (1998)
    Springer
    Journal of applied phycology 10 (1998), S. 461-469 
    Details
    ISSN: 1573-5176
    Schlagwort(e): Cyanobacterium ; Spirulina platensis ; Arthrospira ; CO2 ; organic carbon ; nitrogen ; photosynthesis ; batch culture
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The consequences of the addition of CO2 (1%) in cultures of S. platensis are examined in terms of biomass yield, cell composition and external medium composition. CO2 enrichment was tested under nitrogen saturating and nitrogen limiting conditions. Increasing CO2 levels did not cause any change in maximum growth rate while it decreased maximum biomass yield. Protein and pigments were decreased and carbohydrate increased by high CO2, but the capability to store carbohydrates was saturated. C:N ratio remained unchanged while organic carbon released to the external medium was enhanced, suggesting that organic carbon release in S. platensis is an efficient mechanism for the maintenance of the metabolic integrity, balancing the cell C:N ratio in response to environmental CO2 changes. CO2 affected the pigment content: Phycocyanin, chlorophyll and carotenoids were reduced in around 50%, but the photosynthetic parameters were slightly changed. We propose that in S. platensis CO2 could act promoting degradation of pigments synthetised in excess in normal CO2 conditions, that are not necessary for light harvesting. Nitrogen assimilation was significantly not affected by CO2, and it is proposed that the inability to stimulate N assimilation by CO2 enrichment determined the lack of response in maximum growth rate.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008090402847
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  • 21
    Digitale Medien
    Digitale Medien
    Response of the tropical red seaweed Gracilaria cornea to temperature, salinity and irradiance (1998)
    Springer
    Journal of applied phycology 10 (1998), S. 419-425 
    Details
    ISSN: 1573-5176
    Schlagwort(e): Gracilaria cornea ; photosynthesis ; respiration ; chlorophyll ; phycoerythrin ; Florida ; salinity ; temperature ; irradiance
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The agarophyte Gracilaria cornea, collected over 2.5 y in the Florida Keys, shows adaptations to oceanic salinities and subtropical to tropical water temperatures in its photosynthetic and respiratory responses as measured with a respirometer. No seasonal pattern in responses to irradiance, temperature, and salinity were evident between five collections over a 20-month period, indicating the tropical nature of the populations from Bahia Honda and Pigeon Keys. Concentrations of chlorophyll a (0.09 to 0.41 mg g d wt-1) and phycoerythrin (0.06 to 0.36 mg g d wt- 1) were low and reflect the low nutrient regime of the habitats, especially when compared to laboratory cultured plants. Compensation and saturation irradiances were also low (11–38 and 90–127 μmol photon m-2 s-1), indicating acclimation to lower irradiances in their shallow (1–2 m depth) habitats where turbidity can be high. In comparison with other subtropical and warm temperate species of Gracilaria, G. cornea had lower levels of pigment, but similarly high photosynthetic efficiency, demonstrating shade adaptation; it had only limited tolerance to salinities below 20‰ and temperatures below 15 °C. Thus, G. cornea from the Florida Keys in mariculture would require subtropical to tropical temperatures and stable oceanic salinities.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008021613399
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  • 22
    Digitale Medien
    Digitale Medien
    Dunaliella salina (Chlorophyta) with small chlorophyll antenna sizes exhibit higher photosynthetic productivities and photon use efficiencies than normally pigmented cells (1998)
    Springer
    Journal of applied phycology 10 (1998), S. 515-525 
    Details
    ISSN: 1573-5176
    Schlagwort(e): Chlorophyll antenna size ; damage and repair cycle ; photon use efficiency ; photosynthesis ; photoinhibition ; Dunaliella salina
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The photon use efficiencies and maximal rates of photosynthesis in Dunaliella salina (Chlorophyta) cultures acclimated to different light intensities were investigated. Batch cultures were grown to the mid-exponential phase under continuous low-light (LL: 100 μmol photon m-2 s-1) or high-light (HL: 2000 μmol photon m-2 s-1) conditions. Under LL, cells were normally pigmented (deep green) containing ∼500 chlorophyll (Chl) molecules per photosystem II (PSII) unit and ∼250 Chl molecules per photosystem I (PSI). HL-grown cells were yellow-green, contained only 60 Chl per PSII and 100 Chl per PSI and showed signs of chronic photoinhibition, i.e., accumulation of photodamaged PSII reaction centers in the chloroplast thylakoids. In LL-grown cells, photosynthesis saturated at ∼200 μmol photon m-2 s-1 with a rate (Pmax) of ∼100 mmol O2 (mol Chl)-1 s-1. In HL-grown cells, photosynthesis saturated at much higher light intensities, i.e. ∼2500 μmol photon m-2 s-1, and exhibited a three-fold higher Pmax (∼300 mmol O2 (mol Chl)-1 s-1) than the normally pigmented LL-grown cells. Recovery of the HL-grown cells from photoinhibition, occurring prior to a light-harvesting Chl antenna size increase, enhanced Pmax to ∼675 mmol O2 (mol Chl)-1 s-1. Extrapolation of these results to outdoor mass culture conditions suggested that algal strains with small Chl antenna size could exhibit 2–3 times higher productivities than currently achieved with normally pigmented cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008076231267
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  • 23
    Digitale Medien
    Digitale Medien
    Comparison of PCR-RFLP analysis of the ITS region with morphological criteria of various strains of Dunaliella (1998)
    Springer
    Journal of applied phycology 10 (1998), S. 573-580 
    Details
    ISSN: 1573-5176
    Schlagwort(e): Dunaliella ; ITS ; PCR ; RFLP ; strains ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The genus Dunaliella comprises 28 species defined primarily by morphological and physiological criteria, which vary considerably depending on growth conditions. Concomitantly, the taxonomic status of various species is uncertain. To confirm the taxonomic identity and to better understand the relationship within Dunaliella, seven taxa ( D. salina, D. bardawil, D. tertiolecta, D. parva, D. viridis, D. lateralis, D. peircei) were compared using RFLP analysis of the nuclear rDNA repeats, specifically the internal transcribed spacer regions, including the 5.8S rRNA gene. Volvox aureus was used as an outgroup. A single ITS PCR amplification product was obtained for each taxon. An ITS fragment of ca. 640 bp was present in all the taxa within the subgenus Dunaliella, except for D. salina CCMP 1303 (ca. 540 bp) and D. lateralis (subgenus Pascheria) (ca. 600 bp). A cluster analysis based on the presence or absence of bands generated by digestion of the PCR product with 8 restriction endonucleases (DpnI, HhaI, EcoRI, PvuII, TaqI, HaeIII, MspI, StyI) revealed no correlation between the genetic relationship inferred from the ITS-RFLP data and the morpho-physiological attributes used for taxonomy. In addition, differences in morphology, physiology and in the length and restriction fragment patterns of the ITS region of D. salina CCMP 1303 suggest that this strain does not belong to Dunaliella.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008035422784
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  • 24
    Digitale Medien
    Digitale Medien
    A critical comparison ofGracilaria chilensis andG. sordida (Rhodophyta, Gracilariales) (1990)
    Springer
    Journal of applied phycology 2 (1990), S. 375-382 
    Details
    ISSN: 1573-5176
    Schlagwort(e): Gracilaria ; taxonomy ; organellar DNA restriction ; anatomy ; chromosome number ; interfertility
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Gracilaria chilensis Bird, McLachlanet Oliveira from Chile andG. sordida Nelson from New Zealand have been compared with respect to reproductive anatomy, chromosome number, interfertility, and organellar DNA restriction profiles. No differences were found in reproductive anatomy, which in these species is distinguished by deeptextorii-type spermatangial conceptacles and prominent tubular nutritive cells directed only to the floor of the cystocarp. The species share a chromosome number ofn = 24 and are readily interfertile. Electrophoretic profiles of organellar DNA digested with four different restriction endonucleases were virtually identical between the species except for bands that represented accompanying plasmids. However, previous research has indicated that the four plasmid bands inG. chilensis and the single one inG. sordida have a common origin. On these groundsG. chilensis andG. sordida are
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02180928
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  • 25
    Digitale Medien
    Digitale Medien
    Light dependency of the photosynthetic recovery of Nostoc flagelliforme (1998)
    Springer
    Journal of applied phycology 10 (1998), S. 51-53 
    Details
    ISSN: 1573-5176
    Schlagwort(e): blue-green alga ; cyanobacterium ; Fv/Fmlight ; Nostoc flagelliforme ; photosynthesis ; rewetting
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract PS II photochemical efficiency (Fv/Fm) of Nostoc flagelliforme was examined after rewetting in order to investigate the light-dependency of its photosynthetic recovery. Fv/Fm was not detected in the dark, but was immediately recognized in the light. Different levels of light irradiation (4, 40 and 400 µmol photon m2 s-1) displayed different effects on the recovery process of photosynthesis. The intermediate level led to the best recovery of photochemical efficiency; the low light required longer and the high light inhibited the extent of the recovered efficiency. It was concluded that the photosynthetic recovery of N. flagelliforme is both light-dependent and influenced by photon flux density.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008011531325
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  • 26
    Digitale Medien
    Digitale Medien
    Nitrogen availability influences the biochemical composition and photosynthesis of tank-cultivated Ulva rigida (Chlorophyta) (1998)
    Springer
    Journal of applied phycology 10 (1998), S. 383-389 
    Details
    ISSN: 1573-5176
    Schlagwort(e): ammonium ; C:N ratio ; tank culture ; dietary fibre ; fatty acids ; nitrogen ; photosynthesis ; Ulva rigida
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Physiological and biochemical changes in relation to inorganic nitrogen availability were studied for tank-cultivated Ulva rigida grown under nitrogen- enriched and nitrogen-depleted seawater. U. rigida was initially cultivated in nitrogen-enriched seawater (daily concentrations of NH4+ and NO3- + NO2- ranged between 0.5–1.7 and 0.06–0.15 mg L-1, respectively), then transferred to nitrogen-depleted seawater where photosynthetic capacity decreased to zero after 23 d. At the time (14 d) when photosynthetic rates were lower than 2.0 μmol O2 g-1 FW min-1 and strong bleaching had occurred, some algae were returned to the initial nitrogen-enriched seawater to study recovery from N-limited growth. Data on biochemical composition (chlorophylls, ash, caloric content, fatty acids and dietary fibres) and colouration varied significantly depending on the nitrogen conditions. C:N ratios correlated significantly with biochemical parameters. Fatty acid (FA) synthesis continued during the N-starvation period; saturated and mono-unsaturated FA increased to a maximun of 72.2%, while poly-unsaturated fatty acids (PUFA) decreased to 27.7%. During the N-enriched recovery period, the reverse was found. C:N ratios above 10 correlated with carbohydrate synthesis as shown by the dietary fibre level. Under nitrogen enriched conditions, C:N ratios decreased along with a decrease in fibre level. Under controlled conditions, nitrogen represents a major influence on the development of intensive tank cultivation of Ulva rigida, not only by affecting parameters closely related to nitrogen metabolism but also some clearly influenced by carbon uptake.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008008912991
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  • 27
    Digitale Medien
    Digitale Medien
    A new species ofCortinarius sect.Sericeocybe from Japan (1998)
    Springer
    Mycoscience 39 (1998), S. 333-335 
    Details
    ISSN: 1618-2545
    Schlagwort(e): Cortinarius prunicola ; Cortinarius Sect.Sericeocybe ; new species ; Rosaceae ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Cortinarius prunicola sp. nov., found in orchards and plantations ofPrunus mume, is described and illustrated. It is characterized by its dry and violet-white carpophores, unpleasant odor, and its close association withP. mume in spring and early summer. The differences betweenC. prunicola and similar species are briefly discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02464017
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  • 28
    Digitale Medien
    Digitale Medien
    Unique response of Cyanophyceae to copper (1990)
    Springer
    Journal of applied phycology 2 (1990), S. 293-296 
    Details
    ISSN: 1573-5176
    Schlagwort(e): heavy metal ; photosynthesis ; periphyton ; tolerance ; Cyanophyceae ; genetic adaptation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A study was made of the tolerance to Cu of 11 strains of Cyanophyceae and 7 strains of eukaryotes. These had all been tested within 6 months after isolation for their photosynthetic activity when exposed to Cu (Takamuraet al., 1989) and had repeatedly been subcultured in the medium without Cu for 2 years. Photosynthetic measurements were made in two ways: precultured in medium without Cu or precultured (for one subculture) in medium containing Cu (645 μg 1−1). The results were compared with those obtained within 6 months of isolation. The tolerance of the eukaryotes did not change significantly in any case, but most strains of Cyanophyceae lost their tolerance to Cu within a few subcultures in medium without Cu; however tolerance recovered following one subculture in medium containing an intermediate level of Cu. This rapid adaptation cannot be explained by a constitutive mutation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02180917
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  • 29
    Digitale Medien
    Digitale Medien
    Effects of environmental parameters on net photosynthesis of a free-living brown seaweed,Cystoseira barbata formarepens: determination of optimal photosynthetic culture conditions (1990)
    Springer
    Journal of applied phycology 2 (1990), S. 281-287 
    Details
    ISSN: 1573-5176
    Schlagwort(e): Cystoseira barbata ; photosynthesis ; light ; temperature ; salinity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The net photosynthesis of the Mediterranean brown seaweedCystoseira barbata f.repens is measured according to irradiance, temperature and salinity. There is not only, a good utilization of low light intensities (light-shade adaptation), but also a specific ability to use a broad range of irradiance, which corresponds in the photosynthesis-irradiance curves to a high initial slope and an extended light saturation level from 300 to 1500 μmol photon m−2 s−1; only very high irradiances induce photoinhibition. Maximum net photosynthesis occurred at temperatures ranging from 20 °C to 30 °C. The alga tolerates not only a low level of salinity, but also a slight increase in salinity; however, at more than 47.5 g 1−1 NaCl, oxygen exchange is significantly reduced. Light, temperature and salinity requirements are discussed, taking into account ecological considerations. Yields and quality of alginic acid are presented according to the irradiance and yearly evolutionin situ in order to aid future cultivation of this species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02179786
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  • 30
    Digitale Medien
    Digitale Medien
    Light response curves for Gelidium sesquipedale from different depths, determined by two methods: O2 evolution and chlorophyll fluorescence (1998)
    Springer
    Journal of applied phycology 10 (1998), S. 295-301 
    Details
    ISSN: 1573-5176
    Schlagwort(e): Gelidium sesquipedale ; photosynthesis ; fluorescence ; light response curves ; pigments ; depth
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Photosynthesis-light response curves of Gelidium sesquipedale from the west coast of Portugal (Cape Espichel) were determined at four different depths, 3, 10, 15 and 22 m. Data acquisition using chlorophyll a fluorescence methodology and oxygen electrode measurements were compared. Response curves were determined over an increasing range of irradiance values (I), from darkness to 900 μmol photon m-2 s-1 PAR. In general, light response curves obtained for G. sesquipedale showed a similar pattern whether determined by the chlorophyll fluorescence method or by oxygen evolution. The photosynthetic capacity of G. sesquipedale decreased with depth, as expected, revealing a ‘sun’ and ‘shade’ acclimation pattern, between shallow and deeper waters.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008057008447
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  • 31
    Digitale Medien
    Digitale Medien
    Effects of solar UV stress on chlorophyll fluorescence kinetics of intertidal macroalgae from southern Spain: a case study in Gelidium species (1998)
    Springer
    Journal of applied phycology 10 (1998), S. 285-294 
    Details
    ISSN: 1573-5176
    Schlagwort(e): UV-radiation ; chlorophyll fluorescence ; photosynthesis ; stress tolerance ; electron transport
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Photoinhibition and recovery kinetics after short exposure to solar radiation following three different irradiance treatments of irradiances (PAR, PAR+UVA and PAR+UVA+UVB) was assessed in two intertidal species of the genus Gelidium, Gelidium sesquipedale and G. latifolium, collected from Tarifa (southern Spain) using in vivo chlorophyll fluorescence (PAM fluorometry). After 3 h UV radiation exposure, optimal quantum efficiency (Fv/Fm) in G. sesquipedale decreased between 25 and 35% relative to the control. Under PAR alone, values decreased to 60%. In G. latifolium, photoinhibition did not exceed 40%. Similar results were found for the effective quantum yield (ΔF/Fm′), however, no marked differences in relation to light treatments were seen. When plants were shaded for recovery from stress, only in G. latifolium a significant increase in photosynthesis was observed (between 80 and 100% of control). In contrast, photosynthesis of G. sesquipedale suffered a chronic photoinhibition or photodamage under the three light irradiances. Full solar radiation (PAR+UVA+UVB) affected also the electron transport rate in both species. Here, initial slopes of electron transport vs. irradiance curves decreased up to 60% of controls. Although the recovery kinetic under PAR+UVA+UVB conditions was delayed in G. latifolium, after 24 h recovery this species reached significantly higher than G. sesquipedale. PAR impaired electron trasport only in G. sesquipedale. Overall, both species are characterized by different capacity to tolerate enhanced solar radiation. G. latifolium is a sun adapted plant, well suited to intertidal light conditions, whereas G. sesquipedale, growing at shaded sites in the intertidal zone, is more vulnerable to enhanced UV radiation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008021230738
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  • 32
    Digitale Medien
    Digitale Medien
    Photosynthetic and population growth response of the test alga Selenastrum capricornutum Printz to zinc, cadmium and suspended sediment elutriates (1998)
    Springer
    Journal of applied phycology 10 (1998), S. 145-151 
    Details
    ISSN: 1573-5176
    Schlagwort(e): 14C ; photosynthesis ; population growth ; Selenastrum capricornutum ; suspended sediment elutriate ; zinc ; cadmium
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Short-term 14C-fixation (4 h) Selenastrum capricornutum algal toxicity tests were conducted with Cd (n=8), Zn (n=9) and suspended sediment aqueous elutriates (n=28) and the results were compared to those obtained in a 48 h population growth test. In order to provide more realistic experimental conditions, toxicity tests were carried out in prefiltered nutrient-spiked Lake Geneva water. The population growth inhibition test was significantly more sensitive than the14 C-fixation test for Cd (median EC50-4h and EC50-48h values of 600 and 118 µg L-1, respectively) whereas no significant difference was measured for Zn toxicity (median EC50-4h and EC50-48h values of 97 and 96 µg L-1, respectively). With suspended sediment aqueous elutriates, the relative sensitivity of the two different end points is sample dependent, with ratios of the EC25 for the14 C-fixation: population growth test ranging from 〈0.26 to 〉53.3. Elutriate toxicity shows no apparent relationship between the acute and chronic test, indicating that population growth inhibition cannot be derived directly or predicted from14 C-fixation. Both tests with their specific advantages and limitations provide valuable complementary information to measure the impact of single toxicants or complex mixtures on aquatic plants.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008043931094
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  • 33
    Digitale Medien
    Digitale Medien
    Reduced photoinhibition of a phycocyanin-deficient mutant of Synechocystis PCC 6714 (1998)
    Springer
    Journal of applied phycology 10 (1998), S. 447-452 
    Details
    ISSN: 1573-5176
    Schlagwort(e): dense algal suspension ; light-harvesting pigment ; photosynthesis ; Synechocystis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The effects on photoinhibition of light-harvesting pigments in microalgal cells were examined using the wild type and a phycocyanin- deficient mutant (PD-1) of Synechosystis PCC 6714. Mutant PD-1 showed higher resistance to high light than the wild type in terms of the decline of photosynthetic activity at any light intensity and with various cell densities. This suggests that the loss of productivity induced by high light intensity would be improved by reducing the content of light-harvesting pigments.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008049901939
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  • 34
    Digitale Medien
    Digitale Medien
    Strain selection in Gracilaria spp. 2. Selection for high and low temperature resistance in G. verrucosa sporelings (1990)
    Springer
    Journal of applied phycology 2 (1990), S. 163-171 
    Details
    ISSN: 1573-5176
    Schlagwort(e): Gracilaria ; strain selection ; growth ; photosynthesis ; rubisco ; agar
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A strain selection procedure using Gracilaria verrucosa gametophytic sporelings was found to be an efficient tool for the improvement of Gracilaria strains. Two strains, C-2 and A-18, which were isolated and grown clonally, showed higher growth rates under high and low temperature conditions, respectively, than the local Gracilaria conferta. Growth rate, photosynthesis and chlorophyll, which were measured under different temperature and photon flux densities, demonstrated an overall advantage of the selected strains over the wild type strains of both G. verrucosa and G. conferta. Growth rates were also generally in positive correlation with the carboxylase activity of Rubisco. The G. verrucosa wild type also had a 40% higher agar content than G. conferta. The selected strains thus showed higher potential for outdoor cultivation than local wild type populations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00023378
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  • 35
    Digitale Medien
    Digitale Medien
    Photosynthate production in laboratory cultures (UV conditioned and unconditioned) of Cryptomonas erosa under simulated doses of UV radiation (1998)
    Springer
    Aquatic ecology 32 (1998), S. 297-312 
    Details
    ISSN: 1573-5125
    Schlagwort(e): cryptomonads ; macromolecular ; Phototron ; photosynthesis ; UV radiation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We used a device called a Phototron to measure the effects of UV radiation on the cosmopolitan algae, Cryptomonas erosa, grown in continuous cultures. In the Phototron, we investigated changes in photosynthetic parameters (Pmax – specific production rate at optimal light intensity; α – initial slope of the linear portion of the Photosynthesis-Irradiance curve; and θ – the convexity or rate of bending) and carbon allocation as a function of irradiance at three different environmentally-realistic doses of UV radiation in unconditioned (no prior UV exposure) and conditioned algae (15 d previous UV exposure). For unconditioned control algae, Pmax-Total was lower, although not significantly, than the two highest UV treatments. For conditioned control algae, Pmax-Total was higher, although not significantly, than all UV treatments. Our data suggest that short term (4 h) exposure to low levels of UV (8.09 W m−2 unweighted) does not affect Pmax-Total in C. erosa, but does change the proportion of carbon allocated to lipids and proteins. Also, comparisons of lipids, polysaccharides and proteins as a percent of total carbon uptake between unconditioned and conditioned algae indicate that exposure history to UV radiation can have a negative impact on carbon allocation to lipids and proteins, in a wetland alga species that is crucial to the efficient transfer of energy through freshwater food webs.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009911811188
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  • 36
    Digitale Medien
    Digitale Medien
    Taxonomic review of the species of Pterocladia (Gelidiales, Rhodophyta) (1998)
    Springer
    Journal of applied phycology 10 (1998), S. 237-251 
    Details
    ISSN: 1573-5176
    Schlagwort(e): Gelidiales ; Gelidiella ; Gelidium ; Pterocladia ; Pterocladiella ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Segregating Pterocladiella from Pterocladia stimulated new taxonomic studies of the species originally assigned to Pterocladia. A total of 28 species are ascribed to the genus, one of them with doubts. Thirteen of the 27 names are synonyms. Three of the remaining 14 species belong with Gelidium, including G. americanum, G. mcnabbianum (Dawson) comb. nov. and G. musciformis. Seven other species belong with Pterocladiella, including P. bartlettii (Taylor) comb. nov., P. bulbosa, P. caerulescens, P. caespitosa (Kylin) comb. nov., P. caloglossoides (Howe) comb. nov., P. capillacea and P. melanoidea. Two species are retained in Pterocladia, the type P. lucida and P. rectangularis. Two others, P. heteroplatos and P. media are placed in incertae sedis as additional studies of fertile materials are needed to determine their generic status. The genus Pterocladia now appears to include two large-sized species restricted to Australia-New Zealand. Pterocladiella has 8 small-sized species (including P. minima), mainly inhabiting tropical and subtropical waters. Future research documenting sexual reproduction in Gelidiella and solving the presently recognized heterogeneity in Gelidium will help to trace the relationships between Pterocladiella and these two genera.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008095915164
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  • 37
    Digitale Medien
    Digitale Medien
    Characterization of phenotypically distinct strains of Xanthomonas axonopodis pv. citri from Southwest Asia (1998)
    Springer
    European journal of plant pathology 104 (1998), S. 477-487 
    Details
    ISSN: 1573-8469
    Schlagwort(e): citrus bacterial canker ; detection ; epidemiology ; monoclonal antibodies ; variability ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Strains of Xanthomonas axonopodis pv. citri were isolated from Mexican lime (Citrus aurantifolia) trees in several countries in southwest Asia. These strains produced typical erumpent bacterial canker lesions on Mexican lime but not on grapefruit (C. paradisi). Lesions on grapefruit were watersoaked and blister-like in contrast to the typical erumpent lesions seen after artificial inoculation with all described pathotypes of X. axonopodis pv. citri. This group of strains hydrolysed gelatin and casein and grew in the presence of 3% NaCl as is typical of X. axonopodis pv. citri pathotype A. RFLP analyses and DNA probe hybridization assays also gave results consistent with X. axonopodis pv. citri pathotype A. Metabolic fingerprints prepared with the Biolog® system showed similarities as well as differences to X. axonopodis pv. citri pathotype A. In spite of the physiological and genetic similarities to pathotype A of X. axonopodis pv. citri, these strains had no or very little affinity for polyclonal antiserum prepared against any of the reference strains of X. axonopodis pv. citri and also did not react with monoclonal antibody A1, an antibody that detects all strains of pathotype A of X. axonopodis pv. citri. These strains were also insensitive to bacteriophage Cp3 like X. axonopodis pv. citri pathotype A and unlike X. axonopodis pv. citri pathotype B. We conclude that these strains, designated Xcc-A*, represent a variant of X. axonopodis pv. citri pathotype-A with pathogenicity limited to C. aurantifolia. The existence of extensive genotypic and phenotypic variation within pathotype A of X. axonopodis pv. citri was unexpected and further complicates the systematics of this species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008676508688
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  • 38
    Digitale Medien
    Digitale Medien
    Euglenophyta found exclusively in South America (1998)
    Springer
    Hydrobiologia 369-370 (1998), S. 363-372 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Euglenophyta ; South America ; geographical distribution ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A taxonomic revision of the Euglenophyta found exclusively in South America is presented. The taxonomy, geographical distribution and critical analysis of the synonyms are given. More than two hundred species and infraspecific entities from South America are described, many of them recorded several times in different regions. The genus Trachelomonas comprises the highest number of new taxa, reaching more than 100 entities. It is followed by Phacus (48 taxa), Strombomonas (33 taxa), Euglena (15 taxa) Lepocinclis (14 taxa), and Distigma, Entosiphon and Sphenomonas with one new taxon each.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1017024010906
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  • 39
    Digitale Medien
    Digitale Medien
    A new species of Neocervinia (Copepoda: Harpacticoida: Cerviniidae) from the hyperbenthos of the Hatsushima cold-seep site in Sagami Bay, Japan (1998)
    Springer
    Hydrobiologia 377 (1998), S. 165-175 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Neocervinia itoi ; Copepoda ; Harpacticoida ; taxonomy ; cold-seep ; Japan
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A new species of harpacticoid copepod, Neocervinia itoi (Cerviniidae), is described on the basis of females and copepodids collected from the Hatsushima cold-seep site in Sagami Bay, Japan. It is morphologically very close to its deep-sea congeners N. tenuicauda (Brotskaya, 1963) and N. unisetosa (Montagna, 1981). The new species differs primarily in the segmentation of the antennule and the endopod of both mandible and maxilliped, and in form and shape of the setae on leg 5. The presence of sensillar structures on the proximal part of the antennule is discussed. A key to the species of Neocervinia is presented.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003248419795
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  • 40
    Digitale Medien
    Digitale Medien
    Characterization and transcriptional regulation of the Synechocystis PCC 6803 petH gene, encoding ferredoxin-NADP+ oxidoreductase: involvement of a novel type of divergent operator (1998)
    Springer
    Plant molecular biology 36 (1998), S. 353-363 
    Details
    ISSN: 1573-5028
    Schlagwort(e): ferredoxin-NADP+ oxidoreductase ; petH ; divergent operator ; antisense mRNA ; phosphoribulokinase ; prk Synechocystis PCC 6803 ; photosynthesis ; cyanobacteria
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The petH gene, encoding ferredoxin-NADP+ oxidoreductase (FNR), has been characterised in the unicellular cyanobacterium Synechocystis PCC 6803. Its product, FNR, was heterologously produced and functionally characterized. The start-site of the monocystronic petH transcript was mapped 523 bp upstream of the predicted PetH initiation codon, resulting in an unusually large 5′-untranslated region. The 5′ end of the petH transcript is situated within the open reading frame of phosphoribulokinase (encoded by prk), which is transcribed in opposite orientation with respect to petH. The transcription start site of the prk transcript was mapped 219 bp upstream of the initiation codon, resulting in a 223 bp antisense region between both transcripts. Under many conditions the expression of both genes (i.e. petH and prk) is co-regulated symmetrically at the transcriptional level, as was concluded from both northern hybridization experiments and from primer extension analyses; it became uncoupled, however, when specifically petH expression was stimulated, independent of prk expression, by stressing the Synechocystis cells with high salt concentrations. A model for a new type of bidirectional operator, regulating the expression of petH and prk, is proposed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1005935819038
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  • 41
    Digitale Medien
    Digitale Medien
    Interactive effects of elevated carbon dioxide and growth temperature on photosynthesis in cotton leaves (1998)
    Springer
    Plant growth regulation 26 (1998), S. 33-40 
    Details
    ISSN: 1573-5087
    Schlagwort(e): carbohydrates ; elevated CO2 ; Gossypium hirsutum L. ; interaction ; photosynthesis ; temperature
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Cotton (Gossypium hirsutum L., cv DPL 5415) plants were grown in naturally lit environment chambers at day/night temperature regimes of 26/18 (T-26/18), 31/23 (T-31/23) and 36/28 °C (T-36/28) and CO2 concentrations of 350 (C-350), 450 (C-450) and 700 μL L-1 (C-700). Net photosynthesis rates, stomatal conductance, transpiration, RuBP carboxylase activity and the foliar contents of starch and sucrose were measured during different growth stages. Net CO2 assimilation rates increased with increasing CO2 and temperature regimes. The enhancement of photosynthesis was from 24 μmol CO2 m-2 s-1 (with C-350 and T-26/18) to 41 μmol m-2 s-1 (with C-700 and T-36/28). Stomatal conductance decreased with increasing CO2 while it increased up to T-31/23 and then declined. The interactive effects of CO2 and temperature resulted in a 30% decrease in transpiration. Although the leaves grown in elevated CO2 had high starch and sucrose concentrations, their content decreased with increasing temperature. Increasing temperature from T-26/18 to 36/28 increased RuBP carboxylase activity in the order of 121, 172 and 190 μmol mg-1 chl h-1 at C-350, C-450 and C-700 respectively. Our data suggest that leaf photosynthesis in cotton benefited more from CO_2 enrichment at warm temperatures than at low growth temperature regimes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1006035517185
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  • 42
    Digitale Medien
    Digitale Medien
    Scientific Nomenclature of the Red Howlers from the Northeastern Amazon in Brazil, Venezuela, and the Guianas (1998)
    Springer
    International journal of primatology 19 (1998), S. 879-905 
    Details
    ISSN: 1573-8604
    Schlagwort(e): Alouatta seniculus ; taxonomy ; geographic distribution ; Guianas
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Cytogenetic and morphological studies have begun to reexamine the taxonomy of the red howlers Alouatta seniculus which live throughout the northern and western Amazon basin, in the Guianas, and from northern Colombia and Venezuela, south to Bolivia. We briefly review the current state of knowledge of the taxonomy and distributions of red howlers, in particular, that of the Guianan subspecies. Recently, two names have been applied to populations from this region, Simia straminea Humboldt, 1812, and Alouatta macconnelli Elliot, 1910. Allen (1911, 1916) unquestioningly accepted the validity of A. macconnelli from the Guyana coast, but most subsequent taxonomic revisions (Cruz Lima, 1945; Cabrera, 1957; Husson, 1978) have synonymized it with S. straminea. Tate (1939) and Hill (1962) listed Alouatta seniculus macconnelli, but both doubted its validity. Nevertheless, recent cytogenetic and morphological studies, without due consideration of the taxonomic history of the two scientific names, have led to the resurrection of A. macconnelli, as distinct from S. straminea. The use of the name Alouatta macconnelli has evidently arisen from a cursory reading of Hill (1962) or an uncritical interpretation of his provisional subspecific distribution map or both. There are also contradictory interpretations of a reciprocal translocation as indicating that Simia straminea and Alouatta macconnelli are separate species (Bonvicino et al., 1995) or the same subspecies (Sampaio et al., 1996). Doubts about the type locality of Simia straminea Humboldt, 1812, as given by Hill (1962), led us to research its original description and to conclude that Simia straminea is a synonym of Alouatta caraya and therefore unavailable for Alouatta seniculus. Before A. macconnelli is accepted as the next available name for the Guianan red howlers, however, we advocate a thorough review of Guianan, Venezuelan, and Colombian red howler subspeciation, with due consideration for the taxonomic status of Mycetes auratus and Mycetes laniger Gray, 1845. We note that Alouatta guariba (Humboldt, 1812) is a senior synonym of Alouatta fusca (Saint-Hilaire, 1812).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1020349514553
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  • 43
    Digitale Medien
    Digitale Medien
    The influence of Verticillium dahliae and drought on potato crop growth. 1. effects on gas exchange and stomatal behaviour of individual leaves and crop canopies (1990)
    Springer
    European journal of plant pathology 96 (1990), S. 273-289 
    Details
    ISSN: 1573-8469
    Schlagwort(e): Canopy enclosure ; stomatal conductance ; light response curve ; light use efficiency ; photosynthesis ; Solanum tuberosum L. ; transpiration ; water use efficiency
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Samenvatting Aardappelplanten (Solanum tuberosum L.) cv.Saturna werden onderworpen aan stress als gevolg vanVerticillium dahliae en droogte. In vroege stadia van de groei werden stomataire geleiding, transpiratie en netto fotosynthese bij lichtverzadiging (PAR〉300 W m−2) gemeten aan individuele bladeren en met een mobiel instrumentarium met behulp van gewaskappen. Er werden geen significante verschillen gevonden in de waarden van de stomataire geleiding en de gasuitwisslingskarakteristieken als gevolg vanV. dahliae-besmetting tot een maand na opkomst. Daarna leidde infectie metV. dahliae tot een afname van de stomataire geleiding, transpiratie en netto fotosynthese, speciaal bij oudere bladeren en bij planten die meer aan zonlicht waren blootgesteld. Soms vertoondeV. dahliae interactie met droogte en bleken beide effecten minder dan optelbaar. De hoge waarden van de variatiecoëfficiënten maakten een groot aantal metingen per behandeling noodzakelijk; dit was vooral het geval bij metV. dahliae geïnfecteerde planten hetgeen aantoont datV. dahliae vooral in het begin van de groei niet alle bladeren in gelijke mate aantast. Door de matigende invloed van de integratie van alle bladlagen en mogelijk doordat de bovenste bladeren werden gestimuleerd, werd de totale gewasfotosynthese in mindere mate beïnvloed doorV. dahliae dan de individuele bladfotosynthese. De bovenste niet geïnfecteerde bladeren bleken verantwoordelijk voor het grootste gedeelte van de gewas-fotosynthese. De resultaten tonen aan, dat volgend op een infectie metV. dahliae, de fotosynthese reeds in een vroeg stadium van de groei wordt verminderd als een gevolg van droogtestress in de bladeren.
    Notizen: Abstract Potato (Solanum tuberosum L.) plants cv.Saturna were subjected to infection withVerticillium dahliae and drought stress. At the early stages of growth, stomatal conductance, transpiration and net photosynthesis were measured at light saturation (PAR〉300 m−2) on individual leaves and with mobile field equipment with the aid of field enclosures. No significant changes in stomatal conductance and gas exchange characteristics occurred as a result ofV. dahliae instomatal conductance, transpiration and and photosynthetic rates, especially on older leaves and on plants exposed to direct sunlight for a longer period of time. In combination with drought,V. dahliae only occasionally showed interaction; their effects being less than additive. High values of coefficients of variatoon necessitated a high number of measurements per treatment; the more so in the inoculated plants which shows thatV. dahliae seems to affect certain leaves while not affecting others early in growth. Crop photosynthesis was less reduced byV. dahliae than individual leaf photosynthesis due to the levelling effect of integration over the whole canopy and possibly through a stimulation of the top leaves. The upper non-affected leaves are responsible for the bulk of photosynthetic crop activity. The results indicate that following an infection withV. dahliae photosynthesis is reduced early in growth as a result of drought stress in the leaves.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02000169
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  • 44
    Digitale Medien
    Digitale Medien
    Systematics ofJusticia sect.Pentaloba (Acanthaceae) (1990)
    Springer
    Plant systematics and evolution 169 (1990), S. 219-235 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Acanthaceae ; Justicia ; Siphonoglossa ; Cytology ; flavonoids ; systematics ; taxonomy ; generic relationships
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The transfer of the four taxa ofSiphonoglossa sect.Pentaloba toJusticia is proposed. It is shown that the taxa of this section were placed inSiphonoglossa primarily because of a single-character phenetic relationship and that they correctly belong inJusticia. In addition to morphology, data from cytology and flavonoid chemistry are also presented that support this intergeneric transfer. A key to the taxa and a detailed taxonomic treatment of the section are provided.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00937676
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  • 45
    Digitale Medien
    Digitale Medien
    Evolutionary relationships in thePodalyrieae andLiparieae (Fabaceae) based on morphological, cytological, and chemical evidence (1998)
    Springer
    Plant systematics and evolution 209 (1998), S. 1-31 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Fabaceae ; Podalyrieae ; Liparieae ; Morphology ; chromosome numbers ; chemical compounds ; taxonomy ; generic relationships
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Taxonomic relationships amongst the genera of the southern African tribesPodalyrieae andLiparieae are discussed. Data gained from morphological, cytological and chemical investigations are analyzed cladistically to determine relationships. The genusCadia (tribeSophoreae) is included in the investigation to establish whether it should be transferred to thePodalyrieae. The results clearly indicate that thePodalyrieae andLiparieae are monophyletic and that they should be united, but thatHypocalyptus andCadia should be excluded. Within the monophyletic group, there are two distinct subclades each supported by three apomorphies. The results also show that there is a strong sister relationship betweenAmphithalea andCoelidium. In the taxonomic treatment theLiparieae are placed into synonymy under thePodalyrieae and two subtribes are recognized. A key to the genera in the tribe is given, followed by a synopsis of the genera.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00991521
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  • 46
    Digitale Medien
    Digitale Medien
    Ecogeographical differentiation patterns inAdonis sect.Consiligo (Ranunculaceae) (1998)
    Springer
    Plant systematics and evolution 211 (1998), S. 43-56 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Ranunculaceae ; Adonis ; Morphology ; growth pattern ; taxonomy ; ecology ; climatic requirements ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Adonis sect.Consiligo is split into three subsections based on morphology, growth pattern, pollen and fruit morphology. For all species distribution maps are provided and discussed with regard to their ecology and climatic requirements. These data reveal additional characters that support the classification of the taxa. Most species of the section grow in continental Eurasiatic steppes and mountain steppe habitats. Only the species of subsect.Amurenses grow in Far Eastern temperate forests and prefer a more oceanic climate. The taxonomic position of these strongly divergent species is supported by the distributional and ecological data. The evolution ofAdonis sect.Consiligo occurred under strong climatic control. During evolution the taxa could only slightly widen their ecological amplitude and, thus, ecology remained rather stable except that of the subsect.Amurenses. Ecological and distributional data can be used to validate taxonomy and phylogeny and reveal additional informations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00984911
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  • 47
    Digitale Medien
    Digitale Medien
    Cytogenetic investigations onOenothera nutans (Onagraceae) (1990)
    Springer
    Plant systematics and evolution 169 (1990), S. 69-80 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Onagraceae ; Oenothera sect.Oenothera subsect.Oenothera ; O. nutans ; Chromosomal analysis ; complex analysis ; structural heterozygosity ; complex heterozygosity ; taxonomy ; numerical taxonomy ; factor analysis ; reciprocal translocations ; Sifactors ; lethal factors ; sublethal factors
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Oenothera nutans, common to the Appalachian Mts between 650 and 1 700 m altitude, was investigated cytogenetically and taxonomically. The species is permanently structurally heterozygous. It consists of two genomes of the B-type which are more or less indistinguishable phenotypically. Nearly all of the strains investigated possess a self-incompatibility factor in one of the two complexes. Both complexes show a close relationship to the predominantly homozygousO. grandiflora, a native of the southern lowlands.O. nutans andO. grandiflora possess the same plastid type, plastome III. Probably,O. nutans evolved by an accumulation of reciprocal translocations within an originally structurally homozygous population, which must be regarded ancestral to the present forms ofO. grandiflora.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00935986
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  • 48
    Digitale Medien
    Digitale Medien
    Karyological studies inPelargonium sectt.Ciconium, Dibrachya, andJenkinsonia (Geraniaceae) (1990)
    Springer
    Plant systematics and evolution 170 (1990), S. 151-159 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Geraniaceae ; Pelargonium ; Chromosome numbers ; karyotypes ; karyotype evolution ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Pelargonium sect.Ciconium and sect.Dibrachya have a basic chromosome number of x = 9, whereas sect.Jenkinsonia has x = 9, 11, and 17.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00937700
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  • 49
    Digitale Medien
    Digitale Medien
    Ribosomal RNA genes inQuercus spp. (Fagaceae) (1990)
    Springer
    Plant systematics and evolution 172 (1990), S. 127-139 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Fagaceae ; Quercus ; Gene mapping ; ribosomal RNA genes ; rRNA/DNA hybridization ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The taxonomy of the genusQuercus is still unclear. In order to elucidate the taxonomy of Mediterranean oaks we have analyzed ribosomal RNA genes ofQuercus cerris, Q. coccifera, Q. trojana, Q. ilex, Q. suber, andQ. macrolepis by means of Southern blot hybridization. Oak nuclear DNA was extracted from root tips of 300 acorns and from catkins of single plants. EcoRI and BamHI restriction endonucleases were used. DNA electrophoresis and rRNA/DNA hybridization were performed usingVicia faba rRNA 18 S and 25 S as probes. The rRNA genes of all the species studied have an identical restriction mapping in the 18 S and 25 S regions, while differences in length are present in the intergenic regions.Q. cerris possesses at least four types of genes of 12.1, 11.5, 8.5, and 8.3 kb;Q. coccifera at least three types of 12.4, 10.4, and 10.1 kb;Q. trojana possesses the same rRNA genes asQ. cerris plus another gene type 12.0 kb long, with EcoRI and BamHI restriction sites in the intergenic spacer;Q. ilex at least three types of 12.4, 10.85, and 9.5 kb;Q. suber at least five types of 11.5, 11.0, 8.6, 8.5, and 8.3 kb;Q. macrolepis, finally, at least seven types of 11.5, 11.0, 10.2, 8.6, 8.5, 8.3, and 8.15 kb.Q. coccifera andQ. ilex rDNA appears quite different respect to other species examined, while high similarity seems to exist betweenQ. cerris, Q. trojana, Q. suber, andQ. macrolepis. These results are in agreement with the taxonomic model proposed bySchwarz for the genusQuercus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00937803
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  • 50
    Digitale Medien
    Digitale Medien
    Morphological and anatomical differentiation ofVellozia hirsuta populations (Velloziaceae) (1990)
    Springer
    Plant systematics and evolution 173 (1990), S. 197-208 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Velloziaceae ; Vellozia hirsuta ; Morphological and anatomical variation ; geographical differentiation ; taxonomy ; Flora of the campos rupestres ; Brazil
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The morphological and leaf anatomical differentiation ofVellozia hirsuta is analysed and classified into several types (A1, A2, A4, B3, B5, C3). The species has a relatively wide distribution in the campos rupestres of Minas Gerais in Brazil. The variation of the isolated populations on different mountain ranges is complex, does not follow a clear geographical pattern, and defies taxonomic classification.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940863
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  • 51
    Digitale Medien
    Digitale Medien
    Cytomorphological characters supporting the taxonomic validity ofCyanothece (Cyanoprokaryota) (1998)
    Springer
    Plant systematics and evolution 210 (1998), S. 25-39 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Cyanophyta ; Cyanobacteria ; Cyanothece ; Synechococcus ; Cyanobium ; Ultrastructure ; nucleoids ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The fine structure of the type species of the genusCyanothece Komárek 1976,C. aeruginosa, is described and compared with the main cytological characteristics of morphologically related members of the generaCyanobium, Cyanobacterium andSynechococcus. Several morphological features, such as cell walls with thick outer layers containing a special type of vesicles, position of thylakoids, “keritomy” (net-like appearance of protoplast caused by arrangement of thylakoids, net-like nucleoids and/or by tendency to form intrathylakoidal spaces) and a special structure of mucilaginous envelopes were found to be characteristic of this genus, supporting its separate position among coccal cyanoprokaryotes (cyanobacteria, cyanophytes). The taxonomic significance of ultrastructural features in all mentioned genera is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00984725
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  • 52
    Digitale Medien
    Digitale Medien
    Pollen morphology in theBoragineae (Boraginaceae) in relation to the taxonomy of the tribe (1998)
    Springer
    Plant systematics and evolution 213 (1998), S. 121-151 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Boraginaceae ; Boragineae ; Palynology ; phenetics ; stereostructure ; systematics ; taxonomy ; ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The results of a comparative survey on pollen morphology in theBoragineae by means of light, scanning and transmission electron microscopy are presented and discussed in relation to the taxonomy of the tribe. Multivariate analyses lead to the recognition of 15 pollen morphotypes for which a discriminant key is proposed. The discriminatory characters concern mainly the stereostructural and ultrastructural features of the grains, such as tectum sculpture and aperture morphology, while the number of apertures appears variable within genera and even single species. Seven out of the 12 investigated genera, as currently circumscribed, are matched by palynological data:Anchusella, Borago, Brunnera, Elizaldia, Lithodora, Symphytum andTrachystemon. On account of aperture shape,Lithodora is however closer to theLithospermeae than to theBoragineae. Other genera, and in particularNonea, show a wide variation in tectum ornamentation, shape of grains and number of apertures. Palynological data do not support a broad concept of the genusAnchusa, and point to the autonomy of the ‘satellite’ generaHormuzakia, Gastrocotyle, Phyllocara, Pentaglottis andCynoglottis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00988912
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  • 53
    Digitale Medien
    Digitale Medien
    Biological properties of some nitrogen-fixing associative enterobacteria (1998)
    Springer
    Plant and soil 202 (1998), S. 49-59 
    Details
    ISSN: 1573-5036
    Schlagwort(e): AP PCR ; Erwinia ; Klebsiella ; nitrogen-fixing bacteria ; phytopathogenicity ; ribosomal DNA ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Enterobacteria isolates from potato tubers were able to fix nitrogen, to protect plants against phytopathogens and to produce phytohormones thus increasing the plant yield. These isolates were previously phenotypically identified as Erwinia carotovora; however, they differed from typical E. carotovora in a number of biological characteristics and were found to be nonphytopathogenic (avirulent) due to the lack of pectate lyase activity. A data matrix, containing 31 strains and 105 biological characteristics was used for computer cluster analysis. The avirulent strains formed a separate cluster more closely related to Klebsiella spp. strains (with a 0.67 level of similarity) than to typical phytopathogenic bacteria of the E. carotovora group (with a 0.48 level of similarity). A phylogenetic analysis based on restriction polymorphisms of an amplified ribosomal DNA spacer region revealed that the avirulent strains studied here were different from all Erwinia, Klebsiella and other enterobacteria species strains. The AP PCR/hybridization technique showed cross homology of amplified DNA of these avirulent strains and a lack of such homology with the DNA from strains of other species. Numerical taxonomy data, rDNA analysis and AP PCR/hybridization assays confirmed that these avirulent bacteria may be regarded as an independent group of enterobacteria.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1004356431849
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  • 54
    Digitale Medien
    Digitale Medien
    Isolation and characterization of the membrane-bound cytochrome c-554 from the thermophilic green photosynthetic bacterium Chloroflexus aurantiacus (1990)
    Springer
    Photosynthesis research 23 (1990), S. 29-38 
    Details
    ISSN: 1573-5079
    Schlagwort(e): cytochrome c ; photosynthesis ; photosynthetic bacteria ; electron transport ; Chloroflexus aurantiacus ; green bacteria
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The membrane-bound photooxidizable cytochrome c-554 from Chloroflexus aurantiacus has been purified. The purified protein runs as a single heme staining band on SDS-PAGE with an apparent molecular mass of 43 000 daltons. An extinction coefficient of 28 ± 1 mM−1 cm−1 per heme at 554 nm was found for the dithionite-reduced protein. The potentiometric titration of the hemes takes place over an extended range, showing clearly that the protein does not contain a single heme in a well-defined site. The titration can be fit to a Nernst curve with midpoint potentials at 0, +120, +220 and +300 mV vs the standard hydrogen electrode. Pyridine hemochrome analysis combined with a Lowry protein assay and the SDS-PAGE molecular weight indicates that there are a minimum of three, and probably four hemes per peptide. Amino acid analysis shows 5 histidine residues and 29% hydrophobic residues in the protein. This cytochrome appears to be functionally similar to the bound cytochrome from Rhodopseudomonas viridis. Both cytochrome c-554 from C. aurantiacus and the four-heme cytochrome c-558-553 from R. viridis appear to act as direct electron donors to the special bacteriochlorophyll pair of the photosynthetic reaction center. They have a similar content of hydrophobic amino acids, but differ in isoelectric point, thermodynamic characteristics, spectral properties, and in their ability to be photooxidized at low temperature.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00030060
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  • 55
    Digitale Medien
    Digitale Medien
    The effect of leaf size on mutual shading and cultivar differences in soybean leaf photosynthetic capacity (1990)
    Springer
    Photosynthesis research 23 (1990), S. 67-72 
    Details
    ISSN: 1573-5079
    Schlagwort(e): leaf size ; light ; photosynthesis ; shading ; soybeans ; specific leaf weight
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract This study investigated the basis of the negative relationship between leaf size and photosynthetic rate per unit of area among five cultivars of soybeans. Exposure of developing mainstem leaves to light, and sizes and light saturated photosynthesis rates of those leaves at maturity were compared in cultivars grown in field plots for two years at Beltsville, Maryland, USA. Plants were grown both in stands at 2.5 cm by 1 m spacing and as isolated plants. While cultivar differences in leaf size were large and consistent in both planting arrangements, significant cultivar differences in light saturated photosynthetic rates were found only in plants grown in stands. Similarly, leaf size was significantly correlated with specific leaf weight only for plants grown in stands. The mainstem apex and developing mainstem leaves experienced more severe shading in large-leaved cultivars than in small-leaved cultivars when plants were grown in stands. Thus, cultivar differences in photosynthetic capacity were probably a consequence of differences in the exposure of developing leaves to light.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00030064
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  • 56
    Digitale Medien
    Digitale Medien
    On the nature of the photosynthetic energy storage monitored by photoacoustic spectroscopy (1990)
    Springer
    Photosynthesis research 23 (1990), S. 313-318 
    Details
    ISSN: 1573-5079
    Schlagwort(e): thylakoid membranes ; electron transfer ; photoacoustic spectroscopy ; energy storage ; photosynthesis ; plastoquinone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The photosynthetic energy storage yield of uncoupled thylakoid membranes was monitored by photoacoustic spectroscopy at various measuring beam intensities. The energy storage rate as evaluated by the half-saturation measuring beam intensity (i50) was inhibited by 3-(3,4-dichlorophenyl)-1,1 dimethylurea, by heat inactivation or by artificial electron acceptors specific for photosystem I or photosystem II; and was activated by electron donors to photosystem I. The reactions involving both photosystems were all characterized by a similar maximal energy storage yield of 16±2 percent. The data could be interpreted if we assumed that the energy storage elicited by the photosystems at 35 Hz is detected at the level of the plastoquinone pool.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00034861
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  • 57
    Digitale Medien
    Digitale Medien
    Retrospective of a botanist (1990)
    Springer
    Photosynthesis research 25 (1990), S. 77-82 
    Details
    ISSN: 1573-5079
    Schlagwort(e): autobiography ; chloroplast structure ; chloroplast proteins ; chloroplast lipids ; photosynthesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract An autobiographic report of studies on the elucidation of the structure of the chloroplast is presented here. It deals with the discovery of the lamellar structure of chloroplasts by polarization-microscopy, the representation of their layer-like structure with the ultraviolet microscope and the results obtained by the electron-microscope leading to the discovery of the structural elements of the lamellar system. These lamellar structures were in the form of vesicles, and were named thylakoids. Isolation of the chloroplasts made it possible to determine their chemical composition. Amphiphilic lipids, together with water, create bimolecular layers and, therefore, are responsible for the structure of the thylakoid-membranes. The role of membrane proteins was emphasized. The isolation of the individual polypeptides was possible after dissociation in sodium-dodecyl-sulfate. Antisera to these polypeptides were used to localize them in the membrane. These antisera are able to inhibit special steps in the electron transport. Our results of the spectroscopic examination of photosynthetic membrane components are also discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00035456
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  • 58
    Digitale Medien
    Digitale Medien
    A reassessment of the use of herbicide binding to measure photosystem II reaction centres in plant thylakoids (1990)
    Springer
    Photosynthesis research 24 (1990), S. 109-113 
    Details
    ISSN: 1573-5079
    Schlagwort(e): atrazine ; diuron ; photosystem II ; photosynthesis ; thylakoids
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The binding of the herbicide atrazine to thylakoid membranes is often used to quantify Photosystem II reaction centres. Two atrazine binding sites, with high and low affinities, have been observed on the D1 and D2 polypeptides of Photosystem II, respectively (McCarthy S., Jursinic P. and Stemler A. (1988) Plant Physiol. 86S:46). We have observed that the accessibility of the low-affinity binding sites is variable, being limited in freshly isolated thylakoids or in fresh frozen-thawed thylakoids, but increasing during storage of the membranes on ice. In contrast, the accessibility of the high-affinity binding sites, which are titratable at low concentrations (〈 500 nM) of herbicide, is much less variable, although the dissociation constant is greatly influenced by ethanol. We conclude that to quantify Photosystem II reaction centres by atrazine binding, it is sufficient and more reliable to assay only the high-affinity binding sites.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00032650
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  • 59
    Digitale Medien
    Digitale Medien
    Nucleotide sequence and expression of the two genes encoding D2 protein and the single gene encoding the CP43 protein of Photosystem II in the cyanobacterium synechococcus sp. PCC 7002 (1990)
    Springer
    Photosynthesis research 24 (1990), S. 137-150 
    Details
    ISSN: 1573-5079
    Schlagwort(e): cyanobacteria ; photosynthesis ; psbC gene ; psbD gene ; translational start codon ; overlapping genes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The unicellular photoheterotrophic cyanobacterium Synechococcus sp. PCC 7002 was shown to encode two genes for the Photosystem II reaction center core protein D2 and one gene for the reaction center chlorophyhll-binding protein CP43. These three genes were cloned and their DNA sequences determined along with their flanking DNA sequences. Northern hybridization experiments show that both genes which encode D2, psbD1 and psbD2, are expressed at roughly equivalent levels. For each of the two psbD genes, there are 18 nucleotide differences among the 1059 nucleotides which are translated. The DNA sequences surrounding the coding sequences are nearly 70% divergent. Despite the DNA sequence differences in the genes, the proteins encoded by the two genes are predicted to be identical. The proteins encoded by psbD1 and psbD2 are ∼92% homologous to other sequenced cyanobacterial psbD genes and ∼86% homologous to sequenced chloroplast-encoded psbD genes. The single gene for CP43, psbC, overlaps the 3′ end of psbD1 and is co-transcribed with it. Results from previous sequencing of psbC genes encoded by chloroplasts suggest that the 5′ end of the psbC gene overlaps the 3′ end of the coding sequence of psbD by ∼50 nucleotides. In Synechococcus sp. PCC 7002, the methionine codon previously proposed to be the start codon for psbC is replaced by an ACG (threonine) codon. We propose an alternative start for the psbC gene at a GTG codon 36 nucleotides downstream from the threonine codon. This GTG codon is preceded by a consensus E. coli-like ribosome binding sequence. Both the GTG start codon and its preceding ribosome binding sequence are conserved in all psbC genes sequenced from cyanobacteria and chloroplasts. This suggests that all psbC genes start at this alternative GTG codon. Based on this alternative start codon, the gene product is ∼85% identical to other cyanobacterial psbC gene products and ∼77% identical to eucaryotic chloroplast-encoded psbC gene products.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00032594
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  • 60
    Digitale Medien
    Digitale Medien
    Effect of photon flux density on inorganic carbon accumulation and net CO2 exchange in a high-CO2-requiring mutant of Chlamydomonas reinhardtii (1990)
    Springer
    Photosynthesis research 24 (1990), S. 245-252 
    Details
    ISSN: 1573-5079
    Schlagwort(e): inorganic carbon transport ; light ; Chlamydomonas ; CO2 exchange ; photorespiration ; photosynthesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The effect of photon flux density on inorganic carbon accumulation and photosynthetic CO2 assimilation was determined by CO2 exchange studies at three, limiting CO2 concentrations with a ca-1 mutant of Chlamydomonas reinhardiii. This mutant accumulates a large internal inorganic carbon pool in the light which apparently is unavailable for photosynthetic assimilation. Although steady-state photosynthetic CO2 assimilation did not respond to the varying photon flux densities because of CO2 limitation, components of inorganic-carbon accumulation were not clearly light saturated even at 1100 μmol photons m-2 s-1, indicating a substantial energy requirement for inorganic carbon transport and accumulation. Steady-state photosynthetic CO2 assimilation responded to external CO2 concentrations but not to changing internal inorganic carbon concentrations, confirming that diffusion of CO2 into the cells supplies most of the CO2 for photosynthetic assimilation and that the internal inorganic carbon pool is essentially unavailable for photosynthetic assimilation. The estimated concentration of the internal inorganic carbon pool was found to be relatively insensitive to the external CO2 concentration over the small range tested, as would be expected if the concentration of this pool is limited by the internal to external inorganic carbon gradient. An attempt to use this CO2 exchange method to determine whether inorganic carbon accumulation and photosynthetic CO2 assimilation compete for energy at low photon flux densities proved inconclusive.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00032312
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  • 61
    Digitale Medien
    Digitale Medien
    Studies on thermoluminescence, delayed light emission and oxygen evolution from photosynthetic materials: UV effects (1990)
    Springer
    Photosynthesis research 25 (1990), S. 17-24 
    Details
    ISSN: 1573-5079
    Schlagwort(e): delayed light ; oxygen evolution ; photosynthesis ; thermoluminescence (money plant, pothos aurea leaf)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The effect of ultraviolet light on thermoluminescence, oxygen evolution and the slow component of delayed light has been investigated in chloroplasts and Pothos leaves. All peaks including peak V (48°C) were inhibited by UV. However, the peak at 48°C which was induced by DCMU was enhanced following UV irradiation of chloroplasts at ambient temperature (23°C) whereas peak II (-12°C) and peak III (10°C) which were also induced by DCMU were inhibited. Chloroplasts treated with DCMU and dark incubated for several minutes at ambient temperature prior to recording of glow curves have also shown enhancement of peak at 48°C. A slow component of delayed light and photosystem II activity of chloroplasts were inhibited by UV whereas photosystem I activity was marginally affected. These results corroborate involvement of photosystem II in generating thermoluminescence and slow components of delayed light in photosynthetic materials.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00051732
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  • 62
    Digitale Medien
    Digitale Medien
    Overcoming drought-induced decreases in soybean leaf photosynthesis by measuring with CO2-enriched air (1990)
    Springer
    Photosynthesis research 25 (1990), S. 49-57 
    Details
    ISSN: 1573-5079
    Schlagwort(e): carbon dioxide ; Glycine max ; photosynthesis ; stomatal conductances ; water potential ; water stress
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Soybean [Glycine max (L.) Merr. cv. Williams 82 and A3127] plants were grown in the field under long-term soil moisture deficit and irrigation to determine the effects of severe drought stress on the photosynthetic capacity of soybean leaves. Afternoon leaf water potentials, stomatal conductances, intercellular CO2 concentrations and CO2-assimilation rates for the two soil moisture treatments were compared during the pod elongation and seed enlargement stages of crop development. Leaf CO2-assimilation rates were measured with either ambient (340 μl CO2 l−1) or CO2-enriched (1800 μl CO2 l−1) air. Although seed yield and leaf area per plant were decreased an average of 48 and 31%, respectively, as a result of drought stress, leaf water potentials were reduced only an average of 0.27 MPa during the sampling period. Afternoon leaf CO2-assimilation rates measured with ambient air were decreased an average of 56 and 49% by soil moisture deficit for Williams 82 and A3127, respectively. The reductions in leaf photosynthesis of both cultivars were associated with similar decreases in leaf stomatal conductance and with small increases in leaf intercellular CO2 concentration. When the CO2-enriched air was used, similar afternoon leaf CO2-assimilation rates were found between the soil moisture treatments at each stage of crop development. These results suggest that photosynthetic capacity of soybean leaves is not reduced by severe soil moisture deficit when a stress develops gradually under field conditions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00051735
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  • 63
    Digitale Medien
    Digitale Medien
    Regulation of coupling factor in field-grown sunflower: A Redox model relating coupling factor activity to the activities of other thioredoxin-dependent chloroplast enzymes (1990)
    Springer
    Photosynthesis research 26 (1990), S. 213-222 
    Details
    ISSN: 1573-5079
    Schlagwort(e): chloroplast coupling factor ; induction ; thioredoxin ; regulation ; ATP synthase ; photosynthesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Simultaneous, non-invasive measurements were made of the rate of photosynthetic CO2 fixation and the state of activation of the chloroplast CF1CF0-ATP synthase (CF) in field-grown sunflower (Helianthus annuus L.) during the dark-to-light transition at sunrise. CO2 fixation showed a linear response with light intensity from zero to about 500–700 μE m-2 s-1. However, at light intensities of only 5–22 μE m-2 s-1, the energetic threshold for activation of the CF was found to be significantly lowered (as compared to the pre-dawn state), presumably through reduction of the regulatory sulfhdryl groups of the γ-subunit of the CF. When these studies were extended to chamber-grown plants, it was found that as little as 5 seconds of illumination at 4 μE m-2 s-1 caused apparently full CF reduction. It is clear, therefore, that the catalytic activation of CF is not rate limiting to the induction of carbon assimilation under field conditions during a natural dark-to-light transition at sunrise. A model, based on the redox properties of the regulatory sulfhydryls, was developed to examine the significance of sulfhydryl midpoint potential in explaining the differences in light sensitivity and oxidation and reduction kinetics, between the CF and other thioredoxin-modulated chloroplast enzymes. Computer simulations of the light-induced regulation of three representative thioredoxin-modulated enzymes are presented.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00033134
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  • 64
    Digitale Medien
    Digitale Medien
    Influence of salt stress on primary metabolism of Zea mays L. seedlings of model genotypes (1990)
    Springer
    Plant and soil 123 (1990), S. 217-222 
    Details
    ISSN: 1573-5036
    Schlagwort(e): growth chamber ; nutrient solution ; 15NO3 assimilation ; photosynthesis ; relative growth rate ; seedlings ; short-term NaCl stress
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Short-term studies for comparing some primary metabolic and growth-responses to salt stress in seedlings of two maize genotypes differing in drought resistance were carried out under controlled conditions. Both genotypes revealed high yielding ability in favourable environments. Treatments: Control (Hoagland-Arnon No 1 solution) and salt stress (Hoagland-Arnon solution plus NaCl, Ψs = −0.84MPa). It was found that in both genotypes the activity of the principal metabolic pathway supplying reduced nitrogen (15N) for the synthesis of amino acids and proteins as well as the assimulatory number (14CO2—assimilation relation rate per chlorophyll unit) were decreased under the effect of the stress. These effects were more marked in the resistant genotype. In this genotype the stress induced metabolic activity decline was accompanied by a corresonding reduction of the relative growth rate. Conversely, continuing growth, resulting probably from accumulation of solutes, was observed in the susceptible genotype. On the basis of these and other observations it is assumed that the resistant genotype manifests short-term energy saving stress reactions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00011271
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  • 65
    Digitale Medien
    Digitale Medien
    The influence of salinity on growth, biomass production and photosynthesis of Eucalyptus camaldulensis Dehnh. and Dalbergia sissoo Roxb. seedlings (1998)
    Springer
    Plant and soil 205 (1998), S. 163-169 
    Details
    ISSN: 1573-5036
    Schlagwort(e): biomass ; growth ; photosynthesis ; salinity ; salt-tolerance
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The influence of NaCl salinity on growth, dry-matter production and leaf photosynthesis of seedlings of Eucalyptus camaldulensis Dehnh. and Dalbergia sissoo Roxb. was studied by imposing 4 levels (40, 80, 120 and 160 mM) of NaCl in pot culture. Salinity up to 160 mM did not affect plant survival, but did affect plant growth and dry-matter production depending upon the species and salt concentration. NaCl reduced leaf number and dry-weight of all the plant components, but increased stem dry-weight, especially in E. camaldulensis. Salinization also stimulated total dry-matter production at all the salinity levels in E. camaldulensis but only at 40 mM in D. sissoo. The two species varied in protein and chlorophyll concentration and in leaf photosynthetic rate. Protein and chlorophyll concentration of the plants fell at all the levels of NaCl, except at 40 mM, where stimulation in the photosynthetic carbon assimilation of the plants occurred. However, no distinct relationship between leaf photosynthetic rate and dry-matter production was found. The study indicated that low salt concentrations generally stimulated growth, biomass production and rate of photosynthesis in both the species, and E. camaldulensis appeared more NaCl salt-tolerant than D. sissoo.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1004381021039
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  • 66
    Digitale Medien
    Digitale Medien
    RFLP analysis of a PCR amplified region of chloroplast DNA in eggplant and related Solanum species (1998)
    Springer
    Euphytica 102 (1998), S. 295-299 
    Details
    ISSN: 1573-5060
    Schlagwort(e): chloroplast DNA ; eggplant ; PCR ; RFLP ; Solanum ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract RFLP analysis of a PCR amplified 3.2-kbp region of cpDNA bounded by the conserved sequences in rbc L and ORF 106 was performed in eggplant (Solanum melongena), its related Solanum species, S. incanum, S. virginianum (= S. surattense), S. torvum, S. aethiopicum (= S. gilo), S. aethiopicum (= S. integrifolium), S. violaceum (= S. indicum), S. violaceum (= S. sanitwongsei) and S. mammosum and the reciprocal hybrids between S. aethiopicum (= S. integrifolium) and S. melongena 'Uttara'. The target region of cpDNA was amplified correctly by PCR. The amplified products were digested with each of 10 restriction enzymes (Alu I, Ase I, BamH I, Hinf I, Msp I, Rsa I, ScrF I, Sty I, Taq I and Xba I). Variations of restriction patterns among the species were recognized after digesting the amplified products with each of the seven restriction enzymes, Taq I, Alu I, Rsa I, Sty I, Ase I, Hinf I and Xba I. The restriction patterns divided the examined nine species into the following five clusters, 1) S. melongena and S. incanum, 2) S. virginianum (= S. surattense), 3) S. torvum, 4) S. aethiopicum (= S. gilo), S. aethiopicum (= S. integrifolium), S. violaceum (= S. indicum) and S. violaceum (= S. sanitwongsei) and 5) S. mammosum. The restriction pattern with Alu I in each of the reciprocal hybrids between S. melongena 'Uttara' and S. aethiopicum (= S. integrifolium) was identical with that of seed parent. The present study demonstrated the availability of the PCR-RFLP analysis of cpDNA for assessing taxonomic relationships and identifying cytoplasmic parentage of interspecific hybrids in eggplant and related Solanum species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1018304308608
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  • 67
    Digitale Medien
    Digitale Medien
    Taxonomy of Mexican landraces of maize, Zea mays, based on their resistance to European corn borer, Ostrinia nubilalis (1990)
    Springer
    Euphytica 46 (1990), S. 119-131 
    Details
    ISSN: 1573-5060
    Schlagwort(e): Zea mays ; maize ; Ostrinia nubilalis ; European corn borer ; resistance ; taxonomy ; germplasm ; indigenous land races
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The resistance to the European corn borer, Ostrinia nubilalis (Hubner), of thirty-seven indigenous landraces of Mexican maize was examined. The relationship of resistance and existing taxonomy of maize according to Wellhausen et al., (1952), was subjected to numerical analyses. Variables examined were: seedling DIM-BOA content, the extent of leaf feeding damage by early instar larvae both in the field and in the laboratory, the extent of plant breakage and stalk tunneling by late instar larvae, plant height, and the extent of fungal damage by Gibberella zeae and Ustilago maydis. Significant differences in resistance among the major taxonomic groupings were reflected in the existing taxonomy of maize (Wellhausen et al., 1952). The most resistant landrace grouping was Wellhausen et al.'s Prehistoric Mestizos. Eighty-five percent of a series of modern inbred lines, pools, and Argentine landraces were found to have affinities with one of the more susceptible groupings, the Ancient Indigenous Races, based upon analysis of the resistance data.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00022305
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  • 68
    Digitale Medien
    Digitale Medien
    Physiological factors determining yield in bread wheat. Effects of introducing dwarfism genes (1990)
    Springer
    Euphytica 51 (1990), S. 33-39 
    Details
    ISSN: 1573-5060
    Schlagwort(e): Triticum aestivum ; wheat ; photosynthesis ; chlorophyll fluorescence ; harvest index ; biological yield ; economic yield ; short straw ; dwarfism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Improvements in bread wheat productivity have been related to changes in plant morphology and function associated with a large increase in the harvest index for a more or less constant biological yield. The appearance of short genotypes possessing dwarfism genes may modify markedly the objectives of breeding as the upper limits of the harvest index are approached. The aim of the investigations presented here was to identify some contrasts between short and tall genotypes in terms of the physiological characteristics associated with grain yield, so as to orientate more efficiently the selection of genotypes, with or without dwarfism genes, for productivity. Various parameters of flag leaf functioning (photosynthesis rate, chlorophyll fluorescence index, leaf area duration) were related to the biological and economic yields and the harvest index for two groups of genotypes that were differentiated by their height. For all genotypes, the relationships between the various traits and the grain yield were difficult to ascertain. For the tall genotypes without dwarfism genes, the classical relationships between grain yield, harvest index, flag leaf area duration and net photosynthesis rate were confirmed. Moreover, the rate of chlorophyll fluorescence decrease (Rfd) during the slow Kautsky kinetics phase, which is representative of the leaf photosynthesis at low light, was found to be an excellent marker of economic yield. Chlorophyll fluorescence decrease was closely related to grain yield and also with other factors that are known to be important in its expression (harvest index, flag leaf area duration). In very short genotypes, the biological yield and directly related factors (leaf area, plant height) were the main parameters associated with economic yield, since the harvest index had approached its upper limit. The selection of short genotypes must therefore maintain the biological yield through an increase in the size of the aerial organs to counterbalance the decrease in height.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00022890
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  • 69
    Digitale Medien
    Digitale Medien
    Current perceptions of Photosystem II (1990)
    Springer
    Photosynthesis research 23 (1990), S. 131-162 
    Details
    ISSN: 1573-5079
    Schlagwort(e): photosynthesis ; Photosystem II ; review ; structure/function aspects
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In the last few years our knowledge of the structure and function of Photosystem II in oxygen-evolving organisms has increased significantly. The biochemical isolation and characterization of essential protein components and the comparative analysis from purple photosynthetic bacteria (Deisenhofer, Epp, Miki, Huber and Michel (1984) J Mol Biol 180: 385–398) have led to a more concise picture of Photosystem II organization. Thus, it is now generally accepted that the so-called D1 and D2 intrinsic proteins bind the primary reactants and the reducing-side components. Simultaneously, the nature and reaction kinetics of the major electron transfer components have been further clarified. For example, the radicals giving rise to the different forms of EPR Signal II have recently been assigned to oxidized tyrosine residues on the D1 and D2 proteins, while the so-called Q400 component has been assigned to the ferric form of the acceptor-side iron. The primary charge-separation has been meaured to take place in about 3 ps. However, despite all recent major efforts, the location of the manganese ions and the water-oxidation mechanism still remain largely unknown. Other topics which lately have received much attention include the organization of Photosystem II in the thylakoid membrane and the role of lipids and ionic cofactors like bicarbonate, calcium and chloride. This article attempts to give an overall update in this rapidly expanding field.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00035006
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  • 70
    Digitale Medien
    Digitale Medien
    Detection of photosynthetic energy storage in a photosystem I reaction center preparation by photoacoustic spectroscopy (1990)
    Springer
    Photosynthesis research 24 (1990), S. 201-208 
    Details
    ISSN: 1573-5079
    Schlagwort(e): photosynthesis ; thermal emission ; P700 ; quantum yield ; energy conversion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Thermal emission and photochemical energy storage were examined in photosystem I reaction center/core antenna complexes (about 40 Chl a/P700) using photoacoustic spectroscopy. Satisfactory signals could only be obtained from samples bound to hydroxyapatite and all samples had a low signal-to-noise ratio compared to either PS I or PS II in thylakoid membranes. The energy storage signal was saturated at low intensity (half saturation at 1.5 W m-2) and predicted a photochemical quantum yield of 〉90%. Exogenous donors and acceptors had no effect on the signal amplitudes indicating that energy storage is the result of charge separation between endogenous components. Fe(CN)6 -3 oxidation of P700 and dithionite-induced reduction of acceptors FA-FB inhibited energy storage. These data are compatible with the hypothesis that energy storage in PS I arises from charge separation between P700 and Fe-S centers FA-FB that is stable on the time scale of the photoacoustic modulation. High intensity background light (160 W m-2) caused an irreversible loss of energy storage and correlated with a decrease in oxidizable P700; both are probably the result of high light-induced photoinhibition. By analogy to the low fluorescence yield of PS I, the low signal-to-noise ratio in these preparations is attributed to the short lifetime of Chl singlet excited states in PS I-40 and its indirect effect on the yield of thermal emission.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00032307
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  • 71
    Digitale Medien
    Digitale Medien
    Photoacoustic studies on the dependence of state transitions on grana stacking (1990)
    Springer
    Photosynthesis research 25 (1990), S. 225-232 
    Details
    ISSN: 1573-5079
    Schlagwort(e): state 1-state 2 transitions ; Mutant nicotiana (tobacco aurea mutant Su/su) ; photoacoustics ; photosynthesis ; energy distribution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Photoacoustic detection of oxygen evolution and Emerson enhancement in state 1 and state 2 were compared in a tobacco wild type and mutant (Su/su) deficient in chlorophyll. The mutant shows smaller changes in the distribution of excitation energy between the two photosystems than the wild type. Analysis of Emerson enhancement saturation curves indicates that in the mutant which is deficient in grana partitions and shows less stacking, state 1-state 2 transitions reflect changes in the yield of energy transfer from PS II to PS I (spillover). On the other hand, the wild type containing large grana shows changes in absorption cross-sections of the two photosystems upon state transitions. NaF, a specific phosphatase inhibitor, blocks the transition to state 1, indicating that LHC II phosphorylation has a role in excitation energy regulation in both the mutant as well as the wild type. It is demonstrated that N-ethylmaleimide, a specific sulfhydryl reagent, blocks the transition to state 2, suggesting that a disulfide-sulfhydryl redox couple activates the LHC II kinase in vivo.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00033163
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  • 72
    Digitale Medien
    Digitale Medien
    LED array spectrophotometer for measurement of time resolved difference spectra in the 530–600 nm wavelength region (1990)
    Springer
    Photosynthesis research 25 (1990), S. 317-327 
    Details
    ISSN: 1573-5079
    Schlagwort(e): LED-Array Spectrophotometer ; difference spectroscopy ; time resolved spectra ; photosynthesis ; cytochrome b/f complex ; cytochrome b 559 ; heat-stress
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A new type of computer controlled spectrophotometer is described which is based on an array of independent, monochromatic pulsed light sources consisting of light emitting diodes (LED) equipped with narrow band interference filters. The LEDs are sequentially pulsed at a high repetition rate. The absorbance information at specific wavelengths is sampled in the μs-time range, using a computer-controlled, highly selective technique of synchronous amplification. A first prototype of this LED Array Spectrophotometer allows simultaneous recording of kinetic changes at 16 different wavelengths in the range from 530 to 600 nm, with a time resolution of 1 ms/point. Special features of the new type of spectrophotometer are: Weak integrated measuring light intensity, high signal/noise ratio even with scattering samples like intact leaves, active baseline adjustment by LED current regulation, computer control of system operation and data analysis. To deconvolute the complex absorbance changes in the cytochrome α-band region, ‘standard spectra’ of the major components are stored in computer memory and used for curve fitting of difference spectra and kinetic changes. As an example of application, the light-induced absorbance changes in a heat-pretreated spinach leaf are analysed. The system effectively separates specific absorbance changes of C550, cyt f, cyt b 559 and cyt b 563 from a large background of non-specific changes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00033173
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  • 73
    Digitale Medien
    Digitale Medien
    Computer aided fluorescence imaging of photosynthetic systems (1990)
    Springer
    Photosynthesis research 26 (1990), S. 59-66 
    Details
    ISSN: 1573-5079
    Schlagwort(e): Video imaging ; fluorescence induction kinetics ; photosynthesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A fluorescence video imaging system utilizing relatively inexpensive commercial components is described. The instrument utilizes a black and white CCD video camera detector, a commercial video imaging board and a IBM-AT compatible computer. The color output of the imaging board greatly aids in the users ability to visually discriminate areas of interest in the video field. Software development that enables the user to capture kinetic traces in real time from the video images is also described. The system is used to monitor fluorescence from photosynthetic systems. The usefulness of the system in screening for photosynthetic mutants is also demonstrated. The cost of the system can be kept below $12,000.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00048977
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  • 74
    Digitale Medien
    Digitale Medien
    Genetic diversity of photosynthetic characters in native populations of Triticum dicoccoides (1990)
    Springer
    Photosynthesis research 25 (1990), S. 119-128 
    Details
    ISSN: 1573-5079
    Schlagwort(e): adaptation ; genetic variation ; photosynthesis ; wild emmer
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Wild emmer wheat (Triticum dicoccoides Korn) has shown wide genetic diversity for disease resistance and morpho-physiological traits of economic importance. Our objectives were to test for genetic variation (VG) in photosynthetic characteristics residing within and between native populations sampled from three ecogeographical regions of Israel, and to identify potential sources of high photosynthetic efficiency for future wheat improvement. Accessions sampled in the center of wild emmer distribution (upper Jordan Valley) in a relatively narrow geographical range showed the greatest diversity in CO2-assimilation rate per unit leaf area (A) or per unit chlorophyll (A/Chl). Genetic variation was absent for internal CO2 concentration (Ci) and water-use efficiency (WUE) and generally lacking for stomatal conductance (gs). Leaf area, although quite variable, was not a significant cofactor in assessing genetic potential for photosynthesis. Accessions within a given population showed 10-times more variation in A and A/Chl than populations sampled from different locations in a region. Accessions with the highest photosynthetic efficiency were derived from upland steppic populations located in marginal habitats extending southward into Israel. Some accessions having high photosynthetic capacity (A=32 μmol m-2 s-1) with no significant reduction in leaf size constitute a potentially valuable genetic resource yet untapped for genetic improvement of hexaploid (T. aestivum L.) wheat.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00035460
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  • 75
    Digitale Medien
    Digitale Medien
    Computer-controlled pulse modulation system for analysis of photoacoustic signals in the time domain (1990)
    Springer
    Photosynthesis research 25 (1990), S. 309-316 
    Details
    ISSN: 1573-5079
    Schlagwort(e): photoacoustics ; photosynthesis ; O2-evolution ; gas-exchange ; heat evolution ; chlorophyll fluorescence
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A newly developed photoacoustic system for measurement of photosynthetic reactions in intact leaves is described. The system is based on pulsed light-emitting diodes, the pulse program and pulse response analysis being computer controlled. Separation of various components in the overall photoacoustic signal is achieved by curve fitting analysis of the responses following individual measuring light pulses in the millisecond time domain. This procedure is in distinction to the conventionally used analysis in the frequency domain, with the advantage that various signal components are obtained by on-line deconvolution, yielding simultaneous recordings of photothermal (complement of energy storage) and photobaric (evolution and uptake) signals. The basic components of the new system are described by block diagrams and the principal steps for deconvolution of the overall photoacoustic response are outlined. An example of application with simultaneous recording of chlorophyll fluorescence is given. It is apparent that the photobaric uptake component represents a significant part of the overall signal, particularly during induction of photosynthesis after dark-adaptation. This component probably contains not only O2-uptake but uptake of CO2 as well.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00033172
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  • 76
    Digitale Medien
    Digitale Medien
    Leaf anatomical characteristics in Flaveria trinervia (C4), Flaveria brownii (C4-like) and their F1 hybrid (1990)
    Springer
    Photosynthesis research 26 (1990), S. 49-57 
    Details
    ISSN: 1573-5079
    Schlagwort(e): Chloroplasts ; Kranz anatomy ; photosynthesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Several leaf anatomical and ultrastructural characteristics usually related with photosynthetic capacity were examined in two Flaveria species with strong differences in anatomy and their F1 hybrid. Flaveria trinervia (Spreng.) Mohr (C4) was the female parent and F. brownii A.M. Powell (C4-like) was the male parent. Quantitative anatomical analysis was made on transverse sections of leaves at both the light and electron microscope level. Four kinds of photosynthetic tissues were considered: bundle sheath (BS), mesophyll adjacent to the BS, mesophyll not adjacent to the BS, and larger spongy mesophyll cells. Flaveria trinvervia partitioned a larger proportion of its photosynthetic cells to BS and the mesophyll layer adjacent to BS and also possessed larger chloroplasts, especially in BS, than did F. brownii. These results suggest that although F. brownii is very C4-like, its anatomy is not as completely C4 as is the case for F. trinervia. In the F1 hybrid the relative contribution of the different tissues to the total photosynthetic tissue volume and area per unit leaf area was quite similar to that of F. trinervia. On the other hand, the chloroplast density and size of the F1 hybrid were fairly similar to those of F. brownii, especially in BS. Thus, there was no evidence of maternal inheritance in the chloroplast characteristics studied. A negative correlation (P〈0.05) between chloroplast size and density was observed among species and relicates within each kind of tissue. This correlation was highest (r=−0.94, P〈0.001) for the BS and when values were plotted on a logarithmic scale. Thus, higher chloroplast numbers for F. brownii and the F1 hybrid were offset by larger chloroplasts in F. trinervia. Less complete C4 photosynthesis in F. brownii may be partially due to incomplete development of Kranz anatomy usually associated with C4 photosynthesis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00048976
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  • 77
    Digitale Medien
    Digitale Medien
    Moina weismanni Ishikawa, 1896 (Cladocera, Moinidae) in Central Europe (1990)
    Springer
    Hydrobiologia 190 (1990), S. 33-42 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Crustacea ; Cladocera ; Moinidae ; M. weismanni ; taxonomy ; Central Europe
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Moina weismanni Ishikawa is reported from Czechoslovakia, Hungary, and Yugoslavia. The species was formerly synonymized with Moina micrura Kurz, based on parthenogenotic females. In both species, parthenogenetic females have a characteristic postabdomen, antennules (characters formerly regarded as typical for a variety of M. micrura), and ephippium. Wales are quite different. Examined populations of both species are similar in length-to-width ratio. M. weismanni is typical for small, eutrophic but permanent, and for large temporary water bodies. M. micrura is restricted to the plankton.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00020685
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  • 78
    Digitale Medien
    Digitale Medien
    Daphnia (Ctenodaphnia) hispanica sp. nov., a new daphnid (Cladocera) from Spain (1990)
    Springer
    Hydrobiologia 194 (1990), S. 149-162 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Daphnia (Ctenodaphnia) ; hispanica ; morphology ; taxonomy ; ecology ; Spain
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Daphnia (C.) hispanica n. sp. has thoracic limbs of A ‘D. (C.) atkinsoni type’ and is very similar toD. chevreuxi Richard, 1896. With this speciesD. (C.) hispanica shares the presence of a soft accessory seta on the outer side of the trunk of the first thoracic limb, apparently unique among the genusDaphnia. Although other morphological characteristics are very similar in this two species, a detailed comparison reveals that they can easily be separated as different species. The most useful features in differentiating both species are:D. (C.) hispanica has a dorsal crest in the head, its rostrum is longer, its accesory seta of the first thoracic limb is more developed, the juveniles are not helmeted and its male postabdomen lacks individual denticles on the anal and preanal margin. The new species is, up to now, restricted to Spain and inhabits the temporary and low mineralized waters of the steppe regions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00028416
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  • 79
    Digitale Medien
    Digitale Medien
    Hydrography and characteristics of the phytoplankton in shelf and oceanic waters off southeastern Brazil during winter (July/August 1982) and summer (February/March 1984) (1990)
    Springer
    Hydrobiologia 196 (1990), S. 111-148 
    Details
    ISSN: 1573-5117
    Schlagwort(e): hydrography ; nutrients ; photosynthesis ; subsurface chlorophyll maxima ; southeastern Brazil
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The physical and chemical environment, and the phytoplankton primary production of southeastern Brazil were studied in relation to the general oceanographic structure during two research cruises (winter and summer). In each cruise, a total of 91 stations were occupied. Data were collected on the spatial distribution of nutrients, phytoplankton biomass and photosynthetic capacity over the coastal, shelf and oceanic areas off São Paulo, Paraná and Santa Catarina States. During wintertime, the mixing processes between tropical warm waters of the Brazil Current and subantarctic waters of the Malvinas Current formed strong environmental gradients. The drainings of Rio de La Plata and Lagoa dos Patos are transported northwards by coastal currents, enriching the shelf waters off Santa Catarina State with inorganic nutrients and consequently increasing the chlorophyll ‘a’ to the highest concentrations (〉 3.5 mg m −3) measured during the two cruises. In slope waters chlorophyll values were always low (0.05–0.45 mg m −3). The chlorophyll within the euphotic layer varied from 8.8–36.7 and 1.2–18.5 mg m−2 during winter and summer, respectively. The surface photosynthetic rates during winter and summer cruises ranged respectively from 0.21–9.17 and 0.66–19.60 mgC/mgChl.a/h. The mean rates were higher in nearshore waters and decreased seaward. The thermal structure of the water column affected the vertical distribution of chlorophyll a and photosynthesis within the euphotic zone; During unstratified periods (winter) they were uniformly distributed but the occurrence of subsurface peaks of chlorophyll and strong photosynthetic inhibition of low light adapted cells in deeper layers are associated to the seasonal thermocline. Occasionally, upwelling of deep waters from shelf break enriched the deeper euphotic layers in offshore areas. Intensive upwelling was observed off Paranagua Bay (Parana State) and the mechanisms of its formation are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00006105
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  • 80
    Digitale Medien
    Digitale Medien
    Comparative photosynthetic studies of Ecklonia cava (Laminariales, Phaeophyta) bladelets with and without zoosporangial sori (1990)
    Springer
    Hydrobiologia 204-205 (1990), S. 473-477 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Ecklonia cava ; Phaeophyta ; photosynthesis ; respiration ; seaweed ; zoosporangial sori
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Photosynthetic rates were compared between Ecklonia cava bladelets with and without zoosporangial sori sampled from the subtidal zone (about 5 m deep) in Nabeta Bay, Shimoda, Japan. Photosynthetic rates of bladelets were lower in the sorus portion than in the non-sorus portion on the basis of area, dry weight and chlorophyll a. Respiration rates were higher in the sorus portion than in the non-sorus portion on the basis of area and chlorophyll a, whereas they were almost the same on a dry weight basis. The differences were mainly due to a large difference in dry weight per unit bladelet area between the sorus and the non-sorus portion. Light compensation points were higher in the sorus portion than in the non-sorus portion.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00040273
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  • 81
    Digitale Medien
    Digitale Medien
    Encentrum (Parencentrum) walterkostei n. sp., a new dicranophorid rotifer (Rotatoria: Monogononta) from the high alpine zone of the Central Alps (Austria) (1990)
    Springer
    Hydrobiologia 281 (1990), S. 51-56 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Encentrum ; Dicranophoridae ; alpine rotifers ; psammon ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A new dicranophorid rotifer, Encentrum (Parencentrum) walterkostei n.sp., is described from an oligotrophic alpine lake. The species was abundant in the psammolittoral of the ‘Unterer Schwarzhornsee’, 2543 m above sea level. The main distinguishing taxonomic features of the new species are long, swordshaped toes and only four vitellary nuclei. Its known occurrence in the sandy substrate of only one lake suggests a stenobiontic nature of this apparently oligothermic new species. Taxonomic problems associated with the Encentrum/Dicranophorus group are briefly discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00006555
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  • 82
    Digitale Medien
    Digitale Medien
    On a new species of Keratella (Rotifera: Monogononta: Brachionidae) (1998)
    Springer
    Hydrobiologia 287-388 (1998), S. 35-37 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Rotifera ; Keratella trapezoida n. sp. ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A new species of planktonic rotifer, Keratella trapezoida n. sp. is described from the Yangtze River, P.R. China. The new morphospecies is characterized by its four enclosed dorsal median facets, nearly trapezoid shape of the first median facet on dorsal plate, and the caudal median facet with parallel margins and being open posteriorly.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1017000617930
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  • 83
    Digitale Medien
    Digitale Medien
    Taxonomic status of Oryza glumaepatula Steud. I. Comparative morphological studies of New World diploids and Asian AA genome species (1998)
    Springer
    Genetic resources and crop evolution 45 (1998), S. 197-203 
    Details
    ISSN: 1573-5109
    Schlagwort(e): multivariate analysis ; Oryza ; O. glumaepatula ; O. nivara ; O. rufipogon ; taxonomy ; wild rices
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract This study was carried out to clarify the taxonomic status of the New World diploid wild rice species, Oryza glumaepatula. The morphological variation of 26 diploid rice accessions in the International Rice Genebank at IRRI from South America and Cuba was compared with that of O. rufipogon and O. nivara from Asia. The 28 morphological characters included 16 spikelet and grain, eight leaf and culm, and four panicle characters, and were analyzed using principal component analysis (PCA) and hierarchical agglomerative cluster analysis. The first two principal components accounted for 53.6% of the total variation. The first component was characterized by leaf and sterile lemma characters, 5-panicle dry weight, and grain length, and the second by anther length and its ratio to grain length, grain width, thickness, and 20-hulled grain weight. The characters effectively differentiated the wild rices from Surinam, French Guiana, and the lower Amazon River basin in Brazil, which showed high negative scores along both axes, from other accessions from Venezuela, Colombia, and Cuba, and the Asian species. Most of the accessions from South America are quite distinct from O. rufipogon, with which they have often been grouped as a single species in some taxonomic treatments. Groupings obtained from cluster analysis corresponded closely with the results from PCA. This study supports a distinct taxonomic status of a group of diploid wild rices from South America as O. glumaepatula.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008682316449
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  • 84
    Digitale Medien
    Digitale Medien
    A Contribution to our knowledge of the Taxonomy of discoidal centric diatoms based upon observations of populations from the River Thames, England (1990)
    Springer
    Hydrobiologia 190 (1990), S. 15-32 
    Details
    ISSN: 1573-5117
    Schlagwort(e): freshwater ; River Thames ; centric diatoms ; key ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Centric diatoms collected from the River Thames at Kingston have been separated into ‘types’ (N.B. this term has no nomenclatural or taxonomic implication in this context), the cleaned frustules of which are visibly different when examined by light microscopy. An attempt has been made to correlate observations obtained by light microscopy, stereoscan and transmission electron microscopy, and to make detailed comparisons with descriptions in the literature. Some of the ‘types’ can be referred to known species while others, especially those referable to the genus Stephanodiscus, are more debatable. It is concluded that the separation of discoidal celled centric diatoms into ‘types’ visibly different by light microscopy is a valid basis for the ecological investigation of these planktonic diatoms, even though some of these ‘types’ probably represent morphotypes rather than separate species. A key to the centric diatoms from the Thames is presented together with tabulated characteristics upon which the key is based.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00020684
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  • 85
    Digitale Medien
    Digitale Medien
    A new species of hemibranchiate sphaeromatid isopod of the genus Paracilicaea from Pakistan with the study of developmental stages of the male (1990)
    Springer
    Hydrobiologia 199 (1990), S. 21-28 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Isopoda ; taxonomy ; new species ; intertical rocky habitat ; Pakistan Coast ; development of male ; dimorphism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A new species, Paracilicaea keijii, of hemibranchiate sphaeromatid isopod is described and illustrated from the rocky intertidal zone of Karachi Coast, Pakistan. Four developmental stages of male are described in detail with the help of illustrations. The relationship of P. keijii sp. nov. with two closely allied species and genus Paracilicaea Stebbing, 1910 with Cymodoce Leach, 1814 are discussed. Attention has also been paid to sexual dimorphism of the species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00007830
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  • 86
    Digitale Medien
    Digitale Medien
    Restriction enzyme analysis of variation and taxonomy in the kelp genus Laminaria (Laminariales, Phaeophyta) (1990)
    Springer
    Hydrobiologia 204-205 (1990), S. 105-110 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Laminaria ; molecular biology ; seaweed ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract High levels of phenotypic variation in kelp species necessitate the use of taxonomic markers that are independent of morphology. Restriction fragment length polymorphism (RFLP) analysis of nuclear DNA can provide such markers. In this paper we present the results of an RFLP analysis of cytoplasmic ribosomal DNA (rDNA) in three Laminaria species (L. agardhii, L. digitata, L. groenlandica). Comparison of the restriction maps of the nontranscribed spacer (NTS) in the rDNAs suggests that this method should be useful for the differentiation of these taxa. These results are discussed, as are the applications of RFLP mapping to the identification of field-collected, morphologically variable plants.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00040221
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  • 87
    Digitale Medien
    Digitale Medien
    Taxonomy of phyllophoroid algae: the implications of life history (1990)
    Springer
    Hydrobiologia 204-205 (1990), S. 119-124 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Ahnfeltia ; Gymnogongrus ; life history ; Phyllophora ; Phyllophoraceae ; Rhodophyta ; seaweed ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The Phyllophoraceae Rabenhorst (Gigartinales) is a family that shows a great diversity of life history patterns. The three largest phyllophoroid genera, Ahnfeltia, Gymnogongrus and Phyllophora, all commercial sources of phycocolloids, show the greatest range of life history. Information from life history studies has been of significance to classification of the Phyllophoraceae at the family, generic and specific levels. In the tetrasporophyte of Ahnfeltia plicata, previously known as Porphyrodiscus simulans, tetrasporangia are zonate and borne terminally in small superficial sori in contrast to the chains of cruciate tetrasporangia characteristic of the Phyllophoraceae. A study of reproduction and life history in the type species, A. plicata, from the Atlantic concluded that the unique carposporophyte development, in conjunction with the most primitive pit-plug structure known in the Florideophycidae, justified the proposal of a new family Ahnfeltiaceae Maggs et Pueschel in the Ahnfeltiales Maggs et Pueschel. Most Pacific species of Ahnfeltia are instead phyllophoracean and closely related to Gymnogongrus. Gymnogongrus griffithsiae, the type species, forms tetrasporoblasts whereas the majority form internal cystocarps and have heteromorphic life histories. Proposals to divide the genus by life history type require further detailed morphological and ontogenetic studies of G. griffithsiae. Phyllophora species exhibit at least three different types of life history, tetrasporoblastic, isomorphic and heteromorphic, and this genus could likewise be split along these lines. At the specific level, intraspecific life history variability appears to be related to morphological variation in some species of Gymnogongrus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00040223
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  • 88
    Digitale Medien
    Digitale Medien
    An analysis of taxonomic studies on Rotifera: a case study (1998)
    Springer
    Hydrobiologia 287-388 (1998), S. 9-14 
    Details
    ISSN: 1573-5117
    Schlagwort(e): taxonomy ; evaluation ; Rotifera
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Results are presented of a historical analysis of taxonomic research on Rotifera, as reflected by the case of α-taxonomy of Lecanidae and Dicranophoridae. The number of available names established, as well as the fraction presently considered valid are counted per decade. Two peak periods in taxonomic research are revealed, viz. a minor one in the last decades of the 19th century, and a major one in the 1920s–1930s. Especially work published during the second period contains a high proportion of names that are currently considered valid. The second half of the 20th century witnessed a decrease in quantity, but also in quality of taxonomic research. The basic cause for this is probably the typological approach to a group exhibiting high intraspecific morphological variability, but also poor taxonomic education, as reflected by a high incidence of insufficient descriptions, and poor knowledge of the rules governing zoological nomenclature, are of incisive importance.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1017038510004
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  • 89
    Digitale Medien
    Digitale Medien
    Cross-mating tests re-discovered: a tool to assess species boundaries in rotifers (1998)
    Springer
    Hydrobiologia 287-388 (1998), S. 109-115 
    Details
    ISSN: 1573-5117
    Schlagwort(e): behavior ; mating ; evolution ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The recent isolation of a mate recognition pheromone in the marine rotifer Brachionus plicatilis Müller has shed new light on the mate recognition system of rotifers. One result is improved understanding of the importance of mating behavior as a highly efficient process used by rotifers to choose conspecifics. There are many differences in the main characteristics of mating behavior in members of five different families of rotifers. The present work describes the use of these characteristics to assess species boundaries, especially where boundaries between two or more species are unclear. The method proposed here can assess quantitatively the response of males of one species to females of a questionable taxon by measuring the percentage of matings initiated and the number of completed copulations. The data generated can then be used together with molecular, morphological, and other data to determine the species boundaries. This approach can help distinguish between morphological differences resulting from evolutionary divergence of species and morphological differences induced by environmental or ecological factors.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1017005602735
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  • 90
    Digitale Medien
    Digitale Medien
    Photochemical efficiency of Photosystem II and xanthophyll cycle components in Zea mays leaves exposed to water stress and high light (1998)
    Springer
    Photosynthesis research 56 (1998), S. 57-66 
    Details
    ISSN: 1573-5079
    Schlagwort(e): chlorophyll fluorescence ; C4 plant ; drought ; low CO2 ; photosynthesis ; zeaxanthin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The effects of two light treatments (photosynthetically active photon flux density of either 650 or 1950 µmol m−2 s−1) on the photochemical efficiency of Photosystem II (PS II) (measured as variable to maximum fluorescence ratio) and on the xanthophyll cycle components was studied in wilted Zea mays leaves. For comparison, these parameters were followed under the same light conditions in well-hydrated leaves maintained either in normal or CO2-free air. The net CO2 assimilation of dehydrated leaves declined rapidly as their relative water content (RWC) decreased from 100 to 60% while the PS II efficiency measured after a prolonged dark period of 16 h declined only when RWC leaves was lower than 60%. Furthermore, drought caused an increase in the pool size of the xanthophyll cycle pigments and the presence of a sustained elevated level of zeaxanthin and antheraxanthin at the end of the long dark period. The leaf water deficit enhanced the sensitivity of PS II efficiency to light exposure. During illumination, strong inhibition of PS II efficiency and large violaxanthin deepoxidation was observed in wilted leaves even under moderate photon flux density compared to control leaves in the same conditions. After 2 h of darkness following the light treatment, the PS II efficiency that is dependent on the previous PPFD, decreased with leaf water deficit. Moreover, zeaxanthin epoxidation led to an accumulation of antheraxanthin in dehydrated leaves. All these drought effects on PS II efficiency and xanthophyll cycle components were also obtained in well-hydrated leaves by short-term CO2 deprivation during illumination. We conclude that the increased susceptibility of PS II efficiency to light in wilted maize leaves is mainly explained by the decrease of CO2 availability and the resulting low net CO2 assimilation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1005921127513
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  • 91
    Digitale Medien
    Digitale Medien
    Measurement of photosynthetic oxygen evolution with a new type of oxygen sensor (1998)
    Springer
    Photosynthesis research 56 (1998), S. 223-227 
    Details
    ISSN: 1573-5079
    Schlagwort(e): luminescence quenching ; oxygen electrode ; oxygen optode ; photosynthesis ; pressure sensitive paint
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We measured the light response curve of photosynthetic oxygen evolution by illuminating a leaf disc in an air-tight windowed chamber. Oxygen production was measured by monitoring the quenching of luminescence of an organometallic ruthenium compound. A photodiode based chlorophyll a fluorometer was used to measure the luminescence intensity. Oxygen evolution measurements with a traditional oxygen electrode gave the same numerical values at different light intensities when the same leaf disk was tested. The quality of the measurement signal of the new method was found to be similar to that obtained with the oxygen electrode method. The new luminescence based system is more stable against electrical disturbances than an oxygen electrode, its response to oxygen pressure changes is very rapid, and the new method allows the same basic equipment to be used for chlorophyll fluorescence and oxygen measurements.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1005994311121
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  • 92
    Digitale Medien
    Digitale Medien
    Spectral characterization of NAD(P)H fluorescence in intact isolated chloroplasts and leaves: Effect of chlorophyll concentration on reabsorption of blue-green fluorescence (1998)
    Springer
    Photosynthesis research 56 (1998), S. 291-301 
    Details
    ISSN: 1573-5079
    Schlagwort(e): blue-green fluorescence (BGF) ; intact isolated chloroplasts ; Pisum sativum ; photosynthesis ; pyridine nucleotides ; Spinacia oleracea L
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In the present communication we report a spectral analysis of the blue-green fluorescence related to changes in NAD(P) redox state in chloroplasts and leaves. To assess the contribution of reabsorption and the inner filter effect, we compared transmission and fluorescence at different chloroplast concentrations, and showed that reabsorption by the photosynthetic pigments (chlorophylls and carotenoids) was at the origin of the two peaks in the emission spectrum in vivo. The absence of potential green-emitting fluorophores in chloroplasts was determined by measuring variable and time-resolved fluorescence at different wavelengths. We defined the conditions which optimize the UV-excited blue-green fluorescence signal dependent on NAD(P)H, and we present an example of monitoring of NAD(P)H fluorescence in intact leaves.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1006081209887
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  • 93
    Digitale Medien
    Digitale Medien
    On Pentacoelum hispaniensis, a marine triclad from Spanish freshwater (Platyhelminthes, Tricladida, Maricola) (1990)
    Springer
    Hydrobiologia 199 (1990), S. 101-106 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Tricladida ; Maricola ; Pentacoelum hispaniensis ; taxonomy ; ecology ; biogeography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The marine triclad Pentacoelum hispaniensis is known from a freshwater biotope near Valencia, Spain. Preliminary results suggest a diploid complement of 12 chromosomes for the species. A historical scenario is presented for the occurrence of P. fucoideum in the Caspian Sea and the Baltic Sea, and for the presence of P. hispaniensis in the Mediterranean.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00005602
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  • 94
    Digitale Medien
    Digitale Medien
    Marine Oligochaeta of Jiaozhou Bay, Yellow Sea coast of China (1990)
    Springer
    Hydrobiologia 202 (1990), S. 107-124 
    Details
    ISSN: 1573-5117
    Schlagwort(e): marine Oligochaeta ; Tubificidae ; Naididae ; Enchytraeidae ; Megascolecidae ; taxonomy ; biogeography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Sixteen species of marine Oligochaeta (8 Tubificidae, 1 Naididae, 6 Enchytraeidae, 1 Megascolecidae) are recorded from the Qingdao area, at about 36° N on the Chinese Yellow Sea coast. Taxonomic remarks are given for most species, of which none appears new to science. Limnodriloides victoriensis Brinkhurst & Baker and Enchytraeus kincaidi Eisen, previously known from the Northeast Pacific, are described from Asia for the first time. These, as well as Monopylephorus rubroniveus Levinsen and a Lumbricillus sp., are interpreted as members of a temperate fauna, while all the remaining species have previously been reported from Hong Kong (at about 22° N) and thus are regarded as subtropical/tropical forms in the Yellow Sea.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00027096
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  • 95
    Digitale Medien
    Digitale Medien
    Marine Oligochaeta of Jiaozhou Bay, Yellow Sea coast of China (1990)
    Springer
    Hydrobiologia 202 (1990), S. 107-124 
    Details
    ISSN: 1573-5117
    Schlagwort(e): marine Oligochaeta ; Tubificidae ; Naididae ; Enchytraeidae ; Megascolecidae ; taxonomy ; biogeography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Sixteen species of marine Oligochaeta (8 Tubificidae, 1 Naididae, 6 Enchytraeidae, 1 Megascolecidae) are recorded from the Qingdao area, at about 36° N on the Chinese Yellow Sea coast. Taxonomic remarks are given for most species, of which none appears new to science.Limnodriloides victoriensis Brinkhurst & Baker andEnchytraeus kincaidi Eisen, previously known from the Northeast Pacific, are described from Asia for the first time. These, as well asMonopylephorus rubroniveus Levinsen and aLumbricillus sp., are interpreted as members of a temperate fauna, while all the remaining species have previously been reported from Hong Kong (at about 22° N) and thus are regarded as subtropical/tropical forms in the Yellow Sea.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02208131
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  • 96
    Digitale Medien
    Digitale Medien
    Development and application of a technique for estimating nutrient deficiency in soft sediments (1990)
    Springer
    Hydrobiologia 203 (1990), S. 93-97 
    Details
    ISSN: 1573-5117
    Schlagwort(e): sediments ; nitrogen ; phosphorus ; nutrient limitation ; photosynthesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A diffusion enrichment technique is presented which allows for chemical enrichment of soft surficial and shallow subsurface sediments and subsequent measurement of O2 production. The sediment is enriched by inserting a perforated tube containing dialysis tubing filled with a nutrient/agar mixture. O2 production by surficial sediment is measured using an inverted, translucent, polyethylene chamber over the sediment. The inside of the chamber contains a collapsible bag connected to the water outside the chamber. When water overlying the sediment is withdrawn from a sampling port, it is displaced with water from outside the chamber, thus preventing contamination of water samples with pore water from below. The technique was tested by enriching near-shore sediments in a large oligotrophic lake with inorganic N and P. NHinf4/p+ additions significantly stimulated benthic primary production as measured by 02 production, whereas enrichment with POinf4/3- had no effect.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00005617
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  • 97
    Digitale Medien
    Digitale Medien
    Growth, photosynthesis and agar in wild-type strains of Gracilaria verrucosa and G. conferta (Gracilariales, Rhodophyta), as a strain selection experiment (1990)
    Springer
    Hydrobiologia 204-205 (1990), S. 381-387 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Gracilaria ; growth ; light ; photosynthesis ; RuBPcase ; temperature
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The local species Gracilaria conferta and the foreign G. verrucosa were grown together under a wide range of photon flux density and temperature conditions. Gracilaria verrucosa showed a higher growth rate, especially under low temperatures, and higher photosynthetic performances as well as higher ribulose-1,5-bisphosphate carboxylase activity as compared with G. conferta. Gracilaria verrucosa also showed a better quality and yield of agar, suggesting that this species could be more suitable than G. conferta for outdoor cultivation in Israel and may improve winter growth in ponds. Growth rate and agar quality (gel strength) were rated as the most suitable characteristics influencing the preference of strains for outdoor cultivation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00040260
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  • 98
    Digitale Medien
    Digitale Medien
    Physiological responses of Pterocladia and Gelidium (Gelidiales, Rhodophyta) from the Azores, Portugal (1990)
    Springer
    Hydrobiologia 204-205 (1990), S. 479-482 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Gelidium ; photosynthesis ; physiological responses ; Pterocladia ; Rhodophyta
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Manometric studies were conducted on Pterocladia capillacea, Gelidium latifolium and Gelidium spinulosum from the Azores, Portugal to determine optimal values of temperature, light and salinity for growth. Physiological responses were considered in relation to vertical distribution patterns of these species commonly observed throughout the Azores. Optimal parameters for the growth of Pterocladia capillacea, Gelidium latifolium and G. spinulosum were 17 to 25 °C, a photon flux density between 200 and 300 µmol m−2 s−1 and salinities of 25 to 35‰.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00040274
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  • 99
    Digitale Medien
    Digitale Medien
    Desmids from Guma Valley (Sierra Leone, West Africa) (1990)
    Springer
    Hydrobiologia 208 (1990), S. 235-243 
    Details
    ISSN: 1573-5117
    Schlagwort(e): desmids ; Africa ; taxonomy ; Staurastrum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Twenty-two taxa of desmids are reported from a pool near Guma Valley (Sierra Leone). Six are new to the country. A new variety of Staurastrum hystrix (S. hystrix var. granulatum) is described.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00007788
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  • 100
    Digitale Medien
    Digitale Medien
    Ilyocryptus smirnovi n. sp. (Branchiopoda, Anomopoda) – a new member of the species group Ilyocryptus brevidentatus s. lat. from Australia (1998)
    Springer
    Hydrobiologia 380 (1998), S. 127-139 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Ilyocryptus ; Anomopoda ; new species ; taxonomy ; Australia ; Queensland
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract All representatives of the genus Ilyocryptus with short lateral setae at the postanal margin of the postabdomen may be separated into the compact species group I. brevidentatus s. lat. A new species of Ilyocryptus from this group is described from the Lake Numalla, Queensland, Australia. I. smirnovi n. sp. shows clear morphological differences in the armature of the valve, postabdomen, and several other structures, from all other species of the group. Differences between members of the above-mentioned species group are analogous with those between European species, listed by Štifter (1991).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003296302957
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