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  • Angiosperms  (221)
  • Springer  (221)
  • Krefeld : Geologischer Dienst Nordhein-Westfalen
  • Wien : Geolog. Bundesanst.
  • 2005-2009
  • 1990-1994  (221)
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  • 101
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 175 (1991), S. 93-99 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Pennisetum ruppellii ; Pulmonaria longifolia ; Papaver somniferum ; Triploidy ; infragenomic chromosome pairing ; chromosome morphology ; isozyme numbers
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The genomic evolution of triploid plants with regular bivalent formation is discussed. The conclusion is reached that although all the progeny of an originally triploid individual will be triploid numerically, only part of the progeny will be triploid genomically. The consequences of this for triploid identification by means of chromosome morphology and isozyme numbers is discussed.
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  • 102
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 175 (1991), S. 101-114 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Archamamelis ; Hamamelidaceae ; Hamamelidales ; Hamamelididae ; Cretaceous flowers ; Cretaceous pollen ; Palaeoflora of Sweden
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Lignite fossil flowers (including pollen) and isolated stamens of probable hamamelidalean (possible hamamelidaceous) affinities from the upper Cretaceous (Late Santonian or Early Campanian) of Sweden are described. The flowers are 6–7-merous with probably a double perianth, one whorl of stamens and (2-?)3 carpels. The stamens are disporangiate; each theca opens by a valve towards the centre of the flower. Pollen is tricolpate, tectate-columellate and reticulate; the endexine is lamellated in the apertural region. The gynoecium has free styles and a syncarpous ovary. In the one flower that was serially sectioned the ovary is either non-functional or development of the few (2?) ovules is retarded.
    Materialart: Digitale Medien
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  • 103
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 175 (1991), S. 125-138 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Asteraceae ; Helianthus niveus ; H. petiolaris ; Morphological intergradation ; speciation ; restriction-site variation ; gene lineage analysis ; plant taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Helianthus petiolaris andH. niveus are polytypic species which are morphologically distinct at the periphery of their ranges but intergrade in areas of sympatry.Helianthus niveus includes both annual and perennial members, whereasH. petiolaris is strictly annual. Chloroplast DNA and nuclear ribosomal DNA restriction site data were used to reconstruct the evolutionary history of populations of the two species. Cladistic analyses reveal the following: (1) neither species is monophyletic; (2) the annual habit is derived once in this complex; and (3) the region of morphological intergradation appears to be primary in origin. The significance of interbreeding versus common descent in defining species concepts is discussed in relation to the above cladistic analyses.
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  • 104
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Salicaceae ; Populus tremuloides ; Alpine community ecology ; clonal organisms ; DNA fingerprinting ; population genetics ; rflp analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A recently developed class of DNA endonuclease fragment probes (variously termed “minisatellite,” “DNA fingerprinting,” or “variable number tandem repeat loci” probes) has detected extensive intraspecific genetic variation in tetrapods. Here we use one probe from this class, the M 13 repeat probe (shown previously to yield ”DNA fingerprints” in humans) to examine genetic diversity in the quaking aspen. Comparisons of endonuclease fragment profiles of individuals separated by at least 6km reveals that diversification of alleles in this species has occurred to such an extent that the likelihood of two randomly chosen individuals having indistinguishableHaeIII fragment profiles is c. 3.17 × 10−4. Based on this finding, members of interdigitating clones can be assigned to one or another clone with high statistical confidence. Interdigitating, morphologically cryptic clones were also identifiable. These results demonstrate that some minisatellite probes can be applied to very distant taxa to obtain useful information about genetic variation.
    Materialart: Digitale Medien
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  • 105
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 175 (1991), S. 139-160 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Restionaceae ; Rhodocoma ; Speciation ; phylogeny ; culm anatomy ; rhizome anatomy ; morphology ; taxonomy ; Flora of Africa
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The vegetative and reproductive morphology, culm and rhizome anatomy and seed surface micromorphology ofRhodocoma are described. It is shown that this variation is best contained by recognizing three new species in the genus. These new taxa are described, and the phylogeny of the genus is investigated by cladistic analysis. The environmental parameters and distributions of the species are related to the cladogram. This suggests that the species are at present ecologically separated, and indicates that the speciation may have been sympatric. This is the first support for the hypothesis that sympatric speciation may have been important in the speciose Cape flora.
    Materialart: Digitale Medien
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  • 106
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 176 (1991), S. 11-20 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Cruciferae ; Glucosinolates ; chemotaxonomy ; GC analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Seventeen glucosinolates were identified and quantified by micro-scale GC analysis in Algerian samples fromSisymbrieae, Arabideae, Lepidieae, andBrassiceae tribes of theCruciferae. Major glucosinolates and their amino acid precursors allowed species to fall naturally into tribes as classified byJanchen.
    Materialart: Digitale Medien
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  • 107
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 175 (1991), S. 161-223 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Orchidaceae ; Coryciinae ; Ceratandra ; Evota ; Evotella ; Ommatodium ; Pterygodium ; Anochilus ; Corycium ; Morphology ; phylogeny ; cladistics ; phytogeography ; speciation ; classification ; Flora of southern Africa
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The leaf-anatomy, palynology, seed-morphology, vegetative morphology and especially the highly complicated floral morphology of theCoryciinae s. str. (Diseae: Orchidoideae: Orchidaceae) are described and illustrated in detail. On the basis of these characters the presumed phylogeny, based on a rigorous cladistic analysis, is presented. The cladistic biogeographical analysis of theCoryciinae s. str. shows that it is a member of the Afrotemperate Track, with a pattern of vicariance events typical of the members of this track. An analysis of the patterns of speciation shows that allopatric speciation appears to be rare, and that parapatric speciation across edaphic boundaries may be the most important factor. Proceeding from the information presented, a new classification of the group is proposed in which we recognize the four generaCeratandra, Evotella, Pterygodium andCorycium. The new monotypic genusEvotella comprises a species originally described asPterygodium rubiginosum. The three species of the genusAnochilus are transferred toCorycium andPterygodium. P. magnum, which was originally described asPterygodium but was transferred toCorycium lately, is placed in a monotypic section ofPterygodium.
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  • 108
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 176 (1991), S. 1-10 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Chenopodiaceae ; Beta bulgaris L ; Germplasm collections ; taxonomy ; single linkage cluster analysis ; principal component analysis ; variation patterns
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The objective of this study was to contribute to a better understanding of the variation pattern in leaf beets. 42 biennial samples from a total of 74 entries were described by 17 characters. A group of presumably less selected leaf beets (group A) with narrow petioles was separated from more advanced cultivars by single linkage cluster (SLCA) and principal component analysis (PCA). SLCA sorted the more advanced cultivars into two groups (B and C) based on a simply inherited trait, the leaf colour. These two groups could virtually not be discerned by PCA. Group A contained germplasm similar to provar.vulgaris sensuHelm whereas accessions within group B and C did not easily fit into provar.flavescens. It seems that classical taxonomy does not predict the features of leaf beets precisely enough. It is suggested that this problem can be solved by replacing classical taxonomy in the case of leaf beets by a descriptive database.
    Materialart: Digitale Medien
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  • 109
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 176 (1991), S. 21-31 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Poaceae ; Systematics ; phylogeny ; chloroplast DNA reassociation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Sequence variation in chloroplast DNA (cpDNA) as measured by DNA reassociation was examined in 12 grass species to address systematic problems in thePoaceae at the subfamilial and tribal levels. Two species,Petunia (Solanaceae) andGlycine (Leguminosae), were included to determine degrees of sequence divergence in cpDNA between monocots and dicots. The data were analyzed phenetically and phylogenetically. Species were segregated into four major groups that corresponded to the subfamiliesPooideae, Oryzoideae, Chloridoideae, andPanicoideae. Representatives of thePooideae andOryzoideae grouped together as did members of theChloridoideae andPanicoideae. ThePooideae split into two major groups corresponding to the recently recognized supertribesTriticanae andPoanae. Internodes between subfamily branches were short which might indicate a burst of divergence in the family early in its evolution. Sequence similarity values between the monocot grass species and the two dicot taxa ranged from 0.15 to 0.27, representing the highly conserved sequences of the chloroplast genome.
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  • 110
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 176 (1991), S. 53-61 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; monocotyledons ; Orchidaceae ; Cephalanthera ; Allozymes ; electrophoresis ; genetic variation ; breeding type
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The genetic variation of seven enzymes for a total of nine loci was investigated in three species of terrestrial orchids of the genusCephalanthera:C. longifolia, C. rubra, andC. damasonium. These species are characterized by presenting different breeding types: outbreeding , outbreeding with facultative vegetative reproduction, and inbreeding, respectively. Electrophoretic evidence points to a difference in the behaviour of each of the three species which seems strictly related to the breeding type. On the basis of our resultsC. longifolia behaves as a normal outbreeder, whileC. rubra presents the influence of vegetative reproduction in some populations and not in others.C. damasonium shows a total lack of both among and within populations genetic variation, which is most probably due to the autogamic breeding type.
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  • 111
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 176 (1991), S. 63-74 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Bromeliaceae ; Tillandsia pallidoflavens ; Microsporogenesis ; organelle ultrastructure ; plastids ; periodic acid-thiocarbohydrazine-silver proteinate staining
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract InTillandsia pallidoflavens none of the organelles undergoes fundamental de- and redifferentiation during microsporogenesis. The plastids are amoeboid, exhibit complex internal structures and gradually start accumulating polysaccharides from meiotic prophase I onwards. These observations contradict reports for other taxa. The ultrastructure of mitochondria and dictyosomes, respectively, is more or less orthodox. The extensive ER, which is only poorly stained by standard methods was identified by image intensifiying techniques. The ribosomes are not only associated with the ER or occur as polyribosomes free in the cytoplasm, but can also form more or less dense clusters.
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  • 112
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 176 (1991), S. 75-123 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Asteraceae ; Inuleae s. str. ; Cladistics ; phylogeny ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The interrelationships of the tribeInuleae s. str. have been analysed with a computerized parsimony program (Hennig 86), using theArctotideae as functional outgroup. The results are illustrated with a cladogram and a strict consensus tree. A detailed character discussion is presented. Descriptions of all genera are supplied with brief notes on distribution, references to chemical investigations, and chromosome numbers. Lists of recognized species are also presented in connection to each genus, respectively. 21 new combinations are made, one new genus,Xerolekia A. Anderb., is described,Mollera is reduced to a synonym ofCalostephane, and the genusDuhaldea is resuscitated.Anisopappus was found to be a paraphyletic basal group in the tribe. The paleate generaAsteriscus, Nauplius, Ighermia, Buphthalmum, andXerolekia form one monophyletic group,Inula and other, similar genera were found to constitute the ancestral complex of thePulicaria group.
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  • 113
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 176 (1991), S. 125-131 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Polygonaceae Aconogonon campanulatum ; Heterostyly ; floral dimorphism ; pollination ; dioecy ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Heterostyly is clearly confirmed inAconogonon campanulatum. This distylous species is dimorphic for tepals, styles, stigma surface, stamens, pollen grain size, and pollen sexine ornamentation. The floral shape is campanulate and thrum flowers are slightly larger than pin flowers. Small solitary bees were observed as flower visitors and probably effected pollination. The possible evolution of dioecy via heterostyly within the genusAconogonon is discussed.
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  • 114
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 176 (1991), S. 135-143 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Primulaceae ; Cyclamen hederifolium ; C. africanum ; C. purpurascens ; Chromosome numbers ; karyotypes ; ploidy levels
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Although theCyclamen subg.Cyclamen spp. are morphologically variable, previous studies suggest a superficial cytological uniformity. New chromosome numbers and an indication of karyotypic instability are reported inC. hederifolium andC. africanum that reveal that the cytology of the subgenus is more complicated than previous accounts suggest. The possible significance of these phenomena is discussed. The diploid status ofC. purpurascens has been confirmed and a distinction between the three diploid karyotypes has been described. The cytological variation may help to explain the well documented morphological variation exhibited in these species.
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  • 115
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 176 (1991), S. 145-177 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Asteraceae ; Plucheeae ; Cladistics ; phylogeny ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The tribePlucheeae (Benth.)A. Anderb., has been analysed cladistically by means of a computerized parsimony program (Hennig 86), using theArctotideae as outgroup. The results of the analysis are presented in a consensus tree and one cladogram. Four major monophyletic subgroups can be recognized: TheColeocoma group (3 genera), thePterocaulon group (3 genera), theLaggera group (6 genera), and thePluchea group (12 genera). All recognized genera are described and most genera are supplied with taxonomical notes including comments on their taxonomic status. Genera such asBlumea, Pluchea, andEpaltes are demonstrated to be unnatural assemblages.Monarrhenus andTessaria are both closely related to thePluchea complex. The old generic nameLitogyne Harv. has been taken up for one species ofEpaltes, the genusRhodogeron is reduced to a synonym ofSachsia, and the following new combinations are made;Litogyne gariepina (DC.)A. Anderb., andSachsia coronopifolia (Griseb.)A. Anderb.
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  • 116
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 176 (1991), S. 179-203 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; dicotyledons ; Urticaceae ; Pilea pumila ; Urtica dioica ; Guttation ; hydathodes ; leaf anatomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Laminar hydathodes are known from only three dicot families. InUrticaceae they are associated with minor vein junctions in all five tribes, as surveyed from cleared leaves of 43 species in 30 genera. Only one species lacked hydathodes. Exclusively adaxial hydathodes were found in 28 genera. In tribeElatostemeae, laminar hydathodes inPilea andPellionia species are abaxial, adaxial, or on both surfaces. Guttation was observed in four species.Urtica dioica (adaxial) andPilea pumila (abaxial) were studied anatomically in detail. Hydathodes in the former have normal bundle structure but xylem gaps sometimes occur. In the latter, phloem is displaced in three previously undescribed ways: 1) ends abruptly near hydathode, 2) curves into connecting vein at adjacent junction, or 3) departs xylem, skirts hydathode independently, and rejoins adjacent xylem strand. Laminar hydathodes are a unifying character of theUrticaceae, and they also strengthen its close relationship to theMoraceae.
    Materialart: Digitale Medien
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  • 117
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 176 (1991), S. 221-225 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Papaveraceae ; Fumaria ; Phenetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A paper byWilson & al. (1990) on the taxonomy ofFumaria is commented upon. It is concluded that the lack of congruence between the authors' results and evidence from morphology, chemistry, and crossing experiments renders their approach questionable.
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  • 118
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 177 (1991), S. 1-10 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Fumariaceae ; Sarcocapnos ; Systematics ; chorology ; Mediterranean area
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A biometric study of theSarcocapnos crassifolia complex from eastern Andalusia (Spain), Algeria, and Morocco was carried out. Twentytwo populations were used in a principal components analysis based on 14 variables. The results support the recognition of two species,S. crassifolia andS. pulcherrima, spec. nova. The taxon described byBoissier asS. speciosa (S. crassifolia subsp.Speciosa) is maintained inS. crassifolia.
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  • 119
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 177 (1991), S. 11-16 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Chenopodiaceae ; Stomata ; phylogenetic pathways
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A new stomatal type—paracytic mesoperigenous—which has not been separated from the paracytic mesogenous type in previous studies of theChenopodiaceae, is described. The frequent occurrence of this previously unknown paracytic mesoperigenous type in this family is demonstrated. As a result a new phylogenetic pathway between anisocytic mesoperigenous and paracytic mesogenous types may be drawn.
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  • 120
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 177 (1991), S. 17-26 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Lamiaceae ; Satureja group ; Calamintha menthifolia ; Glandular trichome development ; essential oils ; systematics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Plant material ofCalamintha menthifolia was collected from two populations grown in the Vikos-Aoos area (NW. Greece). The structure and ontogeny of the glandular trichomes and the chemical composition of the secreted essential oil were studied. The leaves ofC. menthifolia have numerous glandular trichomes of three morphological distinct types: 1) glandular scales with a unicellular foot and stalk, and a 12-celled head, 2) glandular hairs with a unicellular foot and stalk, and a unicellular pear-shaped head and 3) glandular hairs with a unicellular foot, a bicellular stalk and a unicellular elongated head. Qualitative and quantitative GC-MS analyses of the essential oils revealed piperitone oxide as the main constituent in both populations. In the light of these results the relationships beweenC. menthifolia and other members of theSatureja group as well as its taxonomy are discussed.
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  • 121
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 176 (1991), S. 227-253 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Asclepiadaceae ; Pollination ultrastructure ; tube germination ; autogamy ; floral biology ; floral structures
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung An sieben Asclepiadaceen-Arten wird der Zusammenhang von Blütenstrukturen mit dem Bestäubungsprozeß untersucht. Die Analyse erfaßt die Bandbreite von einfacher organisierten (Secamone) bis zu hochdifferenziertenAsclepiadaceae, wobei neben dem offenen Blütentyp auch zwei Formen von geschlossenen Blüten (Sisyranthus, Microloma) untersucht werden. Die Blüten weisen unterschiedlich stark elaborierte Strukturen auf, die als Führungshilfen für den Insektenrüssel dienen. Neben der eigentlichen Leitschiene, die teilweise einen hohen Grad an innerer Differenzierung besitzt, sind vor allem Haare und Coronastrukturen an der primären Führung des Bestäuberrüssels beteiligt. Die interstaminale Lage der Nektarien sowie ihr Hinaufreichen bis zur Leitschiene sichert ebenfalls das Zurückziehen des Rüssels durch die Leitschiene. Die Einführung des Rüssels in den Spalt des Klemmkörpers erfordert einen relativ festen Sitz des Corpusculums, der in den hier untersuchten Arten auf drei verschiedenen Wegen erreicht wird: Anheftung an den Antherenrändern, basales Ankleben am Griffelkopf und Fixierung durch einen distalen Vorsprung des Griffelkopfes. MitTylophora spec. wird ein Fall vorgestellt, bei dem Fremdbestäubung wie auch Auskeimen der Pollenschläuche in situ und damit vermutlich Autogamie zugleich vorkommen. — Die übertragenen Pollinien werden gewöhnlich in die Narbenkammer eingezogen, dort keimen die Pollenschläuche aus und dringen an der Unterseite des Narbenkopfes in diesen ein. BeiSecamone erfolgt der Eintritt der Pollenschläuche an der Flanke des Griffelkopfes, beiMicroloma ist eine exakte Positionierung des Polliniums unnötig, auch vor der Leitschiene abgelegte Pollinien keimen und senden ihre Pollenschläuche durch die innere Leitschiene zum Griffelkopf. BeiSecamone undTylophora ist ein gemeinsamer Anfang der Griffelkanäle (Compitum) im Griffelkopf vorhanden, die Pollenschläuche werden hier auf beide Ovarien verteilt, auch wenn sie nur von einem einzigen eingeführten Pollinium stammen. Bei den übrigen fünf Arten sind beide Griffelkanäle isoliert voneinander, eine direkte Zuweisung der Pollenschläuche eines Polliniums zu nur einem Ovar ist hier die Regel. Damit verfolgen diese höher evolviertenAsclepiadaceae eher die Strategie der resource allocation, indem sie bei der vorherrschenden Belegung mit nur einem Pollinium durch die strukturell gelenkte Zuweisung der Pollenschläuche auch nur ein Fruchtblatt zur Reife bringen müssen.
    Notizen: Abstract Aspects of floral biology in relation to floral structures are investigated in seven species ofAsclepiadaceae. Pollinaria removal and insertion by the insect pollinator is aided by various structural devices such as hairs or corona elements guiding the proboscis towards the entrance of the anther slit. The nectary is situated directly below this opening, thus increasing the probability of the proboscis being introduced into the anther slit during retraction. The anther slit itself often displays structural differentiation in adaptation to the guiding of the proboscis and the insertion of a pollinium in cross pollination. These mechanisms are highly elaborated so that they work as well in closed flower types, in which the pollinator does not enter the flower directly, but only introduces its proboscis (Sisyranthus, Microloma). A special feature of pollinaria removal is the variety of ways of fixing the corpusculum against the force of the proboscis when it is drawn into the cleft. — The stigma of all species exceptSecamone is located on the lower surface of the stigma head where it is appressed to the filament tube. In some cases a direct contact of the inserted pollinium with the stigmatic surface does not seem to be necessary for pollen tube germination, probably moistening by nectar suffices in these flowers. WithTylophora spec., a case of in situ pollen tube germination has been studied. — Concerning the path of the pollen tubes, two different strategies are followed.Secamone andTylophora develop a structurally defined compitum, while the other five species have strictly divided stylar canals. In these higher evolved species, the pollen tubes of one inserted pollinium are all directed into one ovary only, thus enabling the plant to allocate its resources to one carpel only in the frequent case of fertilization by one pollinium.
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  • 122
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 177 (1991), S. 27-38 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Caryophyllaceae ; Moehringia intricata ; Taxonomy ; morphology ; Flora of S. Spain
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The new taxonMoehringia intricata subsp.giennensis, from the calcareous mountains of the south-eastern Iberian Peninsula is described. A comparative morphological study with regard to the most closely related taxa, contributes information of leaf anatomy, seed and pollen morphology, ecology and distribution.
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  • 123
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    Plant systematics and evolution 177 (1991), S. 77-80 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Ochnaceae ; Vibrational pollination ; transference of function
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Most members of theOchnaceae possess poricidal anthers that are emptied by pollen collecting bees performing vibrational foraging. In several genera, such asTyleria, Adenarake, and various species ofSauvagesia, however, pollen is released by vibration from the anthers through the porus of a novel structure formed by staminodia. These envelop the androecium and gynoecium. Anthers enclosed in this envelope are often longicidal.
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  • 124
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    Plant systematics and evolution 177 (1991), S. 53-69 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Asteraceae ; Lactuceae ; Krigia ; Nuclear ribosomal DNA (nrDNA) ; inter-cistronic spacer (ITS) ; intergenic spacer (IGS) ; subrepeating unit ; chloroplast DNA (cpDNA) ; allopolyploid ; restriction site mapping ; methylation ; bootstrap resampling analysis ; sequence divergence value ; cladistics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Restriction site and length variations of nrDNA were examined for 51 populations of seven species ofKrigia. The nrDNA repeat ranged in size from 8.7 to 9.6 kilobase (kb). The transcribed region, including the two ITSs, was 5.35 kb long in all examinedKrigia populations. In contrast, the size of the nontranscribed IGS varied from 3.35 to 4.25 kb. Eight different types of length-variations were identified among the 51 populations, including distinct nrDNA lengths in the tetraploid and diploid populations of bothK. biflora andK. virginica. However, a few variations were detected among populations of the same species or within a cytotype. All populations ofKrigia sect.Cymbia share a 600 bp insertion in IGS near the 18 S gene, and this feature suggests monophyly of the section. AllKrigia spp. had a conjugated type of subrepeat composed of approximately 75 basepairs (bp) and 125 bp. Base modifications in the gene coding regions were highly conserved among species. Forty-five restriction sites from 15 enzymes were mapped, 24 of which were variable among populations. Only four of the variable sites occurred in the rRNA coding region while 20 variable sites were detected in the noncoding regions. Collectively, 25 enzymes generated about 66 restriction sites in each nrDNA; this amounts to about 4.3% of the nrDNA repeat. A total of 50 restriction sites was variable, 28 of which were phylogenetically informative. Phylogenetic analyses of site mutations indicated that two sections ofKrigia, sect.Cymbia and sect.Krigia, are monophyletic. In addition, relationships among several species were congruent with other sources of data, such as cpDNA restriction site variation and morphology. Both length and restriction site variation supported an allopolyploid origin of the hexaploidK. montana. The average sequence divergence value inKrigia nrDNA was 40 times greater than that of the chloroplast DNA. The rapid evolution of nrDNA sequences was primarily due to changes of the IGS sequences.
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  • 125
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    Plant systematics and evolution 177 (1991), S. 81-91 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Pyrolaceae ; Pyrola ; Moneses ; Floral scent ; intrafloral scent differentiation ; orientation cues ; poricidal anthers ; pollen flowers ; buzz pollination
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Floral scent was collected by headspace methods from intact flowers, petals, and stamens of four species ofPyrolaceae. The scent samples were analyzed by coupled gas chromatography-mass spectrometry (GC-MS). The floral scent inPyrola spp. is differentiated into a characteristic petal scent—phenyl propanoids and a characteristic stamen scent—methoxy benzenes. InMoneses the scent is characterized by isoprenoids and benzenoids, with a larger proportion of benzenoids in the stamens compared to the petals. Specific anther scents may promote foraging efficiency in buzz-pollinated species and enhance flower fidelity. Variation in floral scent composition is consistent with the taxonomic relationships among the genera and species examined.
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  • 126
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    Plant systematics and evolution 177 (1991), S. 111-115 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Styracaceae ; Styrax ; Pamphilia ; Karyology ; chromosomes ; evolution and systematics in tropical woody plants
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Chromosome numbers and karyomorphological characters have been investigated inPamphilia andStyrax (Styracaceae). Counted for the first time in the genus, two species ofPamphilia were found to have 2n = 16. The twoStyrax spp. investigated share withPamphilia the same chromosome number, a peculiar condensation behaviour of the chromosomes (Fig. 1a–c) and the same type of semi-reticulate interphase nucleus, results which indicate a close relationship of the two genera. The base number inStyracaceae is probably x = 8 (2n = 2x = 16) with stabilized triploids inHalesia andPterostyrax (2n = 3x = 24). A preliminary comparison withSapotaceae andEbenaceae does not allow a general karyological characterisation of the orderEbenales.
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  • 127
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    Plant systematics and evolution 177 (1991), S. 161-164 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Oxalidaceae ; Hypseocharis ; Floral anatomy ; systematics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The floral anatomy of threeHypseocharis spp. has been studied. The genus resemblesOxalidaceae as well asMonsonia andSarcocaulon of theGeraniaceae. As it is closer toGeraniaceae than toOxalidaceae, it perhaps serves as a connecting link between them.
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  • 128
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    Plant systematics and evolution 177 (1991), S. 117-138 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Umbelliferae ; Angelica ; Chromosome numbers ; karyotypes ; karyosystematics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Morphometric karyotype characters were studied in 25Angelica spp. (Umbelliferae, Apioideae) and in one species of the related genusTommasinia. For three species the chromosome numbers are new. In our study the majority of the species investigated are diploids with 2n = 22, some are tetraploids with 2n = 44 (for these tetraploids also diploid cytotypes are reported in the literature). Among the diploid species,A. miqueliana has a distinct karyotype consisting of submetacentric and acrocentric chromosomes only, the remaining diploids with 2n = 22 as well as tetraploids with 2n = 44 have rather symmetrical karyotypes, consisting of metacentric and submetacentric chromosomes. The very different chromosome number 2n = 28 has been found inA. gmelinii. Its karyotype includes two distinct groups of chromosomes: 8 pairs of rather large metacentrics and submetacentrics and 6 pairs of very short and asymmetrical chromosomes. Chromosome numbers and structures appear to be useful in the taxonomy of some intrageneric taxa inAngelica.
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  • 129
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Cyperaceae ; Carex laevigata ; Agmatoploidy ; chromosome fusion ; chromosome fission ; cytogenetic evolution ; Flora of the Iberian Peninsula
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In this paper cytogenetic studies on 64 specimens from 20 Iberian populations ofCarex laevigata (Cyperaceae) are presented. Chromosome behaviour in meiosis suggests that the different chromosome numbers obtained (ranging from 2n = 69 to 2n = 80) were distributed according to an increasing geographic gradient of chromosome fission along the North → South direction. Four relatively stable areas were also delimited according to chromosome numbers displayed by this species, i.e. 2n = c. 72, c. 74, c. 76, and 78. The meiotic behaviour ofCarex ×deserta (C. laevigata ×C. binervis) was also studied.
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  • 130
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    Plant systematics and evolution 177 (1991), S. 139-148 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Lemnaceae ; Lemna minor ; Allozymic variation ; clonal propagation ; morphometry ; cosmopolitan distribution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Allozymic and morphometric variation was studied in 28 clones ofLemna minor. This variation was compared with the corresponding variation in four clones ofLemna gibba and four clones ofSpirodela polyrrhiza. A high level of allozymic variation was observed among the clones, despite having been grown under uniform laboratory conditions for several years and despite its quasi-exclusive clonal means of propagation. Based on degree of allozymic similarity,Spirodela polyrrhiza was distinguished from the twoLemna species but the latter species were genetically indistinguishable. Allozymic similarity among clones ofLemna minor was not related to morphometric similarity, nor was it related to the degree of geographic separation or climatic similarity of their sites of origin. The results suggest that allozymic variation among these clones ofLemna minor may be largely neutral and not a consequence of differential selection.
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  • 131
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    Plant systematics and evolution 177 (1991), S. 165-174 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Salicaceae ; Populus ; Ribosomal RNA genes ; restriction enzyme maps ; rDNA analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Ribosomal DNA genes fromP. deltoides have been cloned and specific sequences of the 25 S and 18 S rDNA region, labelled by digoxigenin, have been used to determine the rDNA structure ofPopulus tremula, P. fremontii, P. maximowiczii, P. yunnanensis, P. nigra, P. wislizenii, P. alba. The restriction maps of the coding region appeared to be similar among the examined species and with those ofP. deltoides andP. trichocarpa, reported in a previous paper. Inter- and intraspecific variation in rDNA repeat unit length have been revealed after EcoRI digestions. SstI and XbaI restriction sites have been found at different positions in the IGS of some species. The polymorphic fragments generated by SstI digestion allowed the identification of the hybrid origin of some genotypes. The number of rDNA genes in the genome ofP. deltoides has been estimated to be about 2 000 copies. Finally, the usefulness of these studies inPopulus spp. taxonomy and forestry genetics is discussed.
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  • 132
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    Plant systematics and evolution 177 (1991), S. 175-184 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Poaceae ; Zea mays subsp.mays ; Opal phytoliths ; paleoenvironments ; cultivation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Maize (Zea mays L. subsp.mays) has been identified in archaeological contexts by a high proportion of large cross-shaped phytoliths. Given the numerous races of maize, this study was undertaken to determine if differences below the species level could be noted. It was also designed to see if phytoliths differed in various plant parts at various stages of growth. Several races were grown under experimental conditions. No significant differences were found. Furthermore, few phytoliths alleged to be diagnostic of maize were discovered. Systemic studies of maize and analyses of prehistoric cultivation by means of phytoliths seem not to be as promising as some researchers have argued.
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  • 133
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    Plant systematics and evolution 177 (1991), S. 185-192 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Campanulaceae ; Campanula dichotoma group ; Hybridization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Four supposedly closely related taxa were crossed artificially to test for hybridization barriers. Intra- as well as inter-specific crossings were made. The intra-specific crossings resulted in a high portion of viable hybrids, whereas hybridization barriers were found in all inter-specific combinations except one. The hybrids were non-viable at different levels, viz., (1) no seeds germinated, (2) seeds formed lethal chlorotic seedings, or (3) seeds formed chlorophyllous seedlings which survived the cotyledonary stage, but developed into intermediate forms with low pollen production and/or a strongly reduced pollen viability. Crossings betweenCampanula afra and any of the other three taxa resulted in a non-viable progeny. The crossing capacity amongC. occidentalis, C. kremeri, andC. dichotoma varied. Combinations with large-flowered maternal taxa and small-flowered paternal ones usually failed, whereas a high number of the reciprocal crossings produced hybrids which survived the cotyledonary stage. The hybrid plants varied in pollen viability and pollen production, however. It is concluded that theCampanula dichotoma group should be treated as comprising four distinct species.
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  • 134
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    Plant systematics and evolution 177 (1991), S. 193-211 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Ranunculaceae ; Batrachium ; Ranunculus ; Karyology ; chromosome number ; chromosome morphology ; polyploidy ; Flora of the Aegean islands
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract This paper is the first report of an investigation on differentiation and evolutionary pattern inRanunculus subg.Batrachium mainly on the Aegean islands and treats the karyology in the subgenus. The following taxa and chromosome numbers are recorded.R. peltatus subsp.peltatus: 2n = 32, subsp.baudotii: 2n = 32, subsp.saniculifolius: 2n = 16, 32, and 40;R. peltatus s.l.: 2n = 32 and 48;R. penicillatus subsp.pseudofluitans: 2n = 16;R. rionii: 2n = 16;R. sphaerospermus: 2n = 16;R. trichophyllus: 2n = 32, 40, and 48;R. tripartitus: 2n = 48. The karyotypes show certain interspecific differences in chromosome size, in number of chromosome types according to centromere position and in occurrence and position of satellite chromosomes. r-Index and RCL have been calculated.
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  • 135
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    Plant systematics and evolution 177 (1991), S. 221-234 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Leguminosae ; Papilionoideae ; Vicieae ; Vicia ; Vetch ; chromosome number ; DNA amount ; microdensitometry ; cytotaxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Collected material of rare and newVicia spp. was investigated from a cytotaxonomic point of view. Nineteen species were examined in total. The study includes 14 novel chromosome counts and measurements of DNA amount, as well as a comparison of chromosome morphology between species. The results of the cytological study support to an extent a recent taxonomical revision of subgenusVicia.
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  • 136
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Poaceae ; Phragmites australis ; Weeds ; isozyme variation ; infrared reflectance ; polyploidy ; clones ; Mississippi River delta
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Isozyme variation was investigated in populations ofPhragmites australis (Poaceae) which have recently invaded and taken over marsh habitat of the Mississippi River delta. Infrared aerial photographs in the Garden Island Bay subdelta of the extensiveP. australis populations reveal distinct, clone-like circular patches within a predominant background. Preliminary evidence indicates that the infrared color differences represent distinct morphological types. However, there are no obvious environmental factors that could account for the peculiar patterns.P. australis collections were taken from five separate and distinct “patches” and adjacent “background”. Only two electrophoretic phenotypes were found: one from “patches” and one from the “background”. In comparing the two, 20% of the 40 loci scored are fixed for alternate alleles. These results indicate a clear correspondence of infrared reflectance with electrophoretic phenotype. In addition, the genetic uniformity as evidenced by the discovery of only two electrophoretic phenotypes supports the contention that the recent spread ofP. australis throughout the Mississippi River delta has been primarily, if not exclusively, a result of vegetative propagation.
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  • 137
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    Plant systematics and evolution 178 (1991), S. 9-25 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Ranunculaceae ; Caltha palustris ; Chloroplast DNA ; chloroplast genes ; phylogeny ; restriction site maps ; sequence divergence
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A restriction site map of the chloroplast genome ofCaltha palustris L. (Ranunculaceae) has been constructed for 13 restriction endonucleases using filter hybridization with cloned tobacco chloroplast DNA fragments. A size of 153.8 kb has been estimated for theCaltha chloroplast genome. Forty-six chloroplast genes and four open reading frames have been mapped using small tobacco chloroplast gene probes. Chloroplast DNA sequence divergence has been estimated for all pairs of five species ofRanunculaceae, Caltha palustris, Ranunculus bulbosus, R. fascicularis, R. recurvatus, andTrollius ledebourii, and ranges between 0.2% and 9.6% for the total genome. Divergence values are much higher in the small and large single copy regions than in the inverted repeat. Phylogenetic relationships between the five species have been hypothesized using chloroplast DNA restriction site mapping. One hundred and six informative restriction site mutations have been detected using eleven restriction endonucleases. Cladistic analyses of the restriction site mutations have been performed using Wagner and Dollo parsimony algorithms, and confidence intervals have been calculated for the resulting monophyletic groups using bootstrapping. It is demonstrated that restriction site comparisons are applicable to theRanunculaceae on intergeneric level, with the exception of groups having extensive genomic rearrangements. Moreover, sequence divergence is low enough at the interspecific level to allow phylogenetic analyses within genera such asRanunculus.
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  • 138
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    Plant systematics and evolution 178 (1991), S. 55-63 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Ranunculaceae ; Helleborus viridis ; H. odorus subsp.laxus ; H. niger ; H. foetidus ; Storage lipid ; fatty acid composition ; life form
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Root and rhizome of fourHelleborus species:H. viridis, H. odorus, H. niger, H. foetidus were examined throughout a two-year period in order to determine the variation of lipid content and fatty acid composition during the ontogenetic cycle. In the deciduous geophytesH. viridis andH. odorus subsp.laxus the lipid content reaches its maximum during the quiescent phase, whereas in the evergreen geophyteH. niger the lipid content is highest during the main growth period. In the chamaephyteH. foetidus lipid content is always very low and it does not show variation throughout the year. In all species the fatty acids detected in the neutral fraction are myristic, palmitic, stearic, oleic and linoleic acid. Palmitic and linoleic acid are always present in larger quantities. The pattern of the relative content of saturated/unsaturated fatty acids seems to be linked to the life form of these species.
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  • 139
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    Plant systematics and evolution 178 (1991), S. 95-105 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Asclepiadaceae ; Asclepiadeae ; Cynanchinae ; Sarcostemma ; Floral anatomy ; floral morphology ; pollination
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Field observations on pollination in New World species of the genusSarcostemma R. Br. sensuHolm are reported. Morphological and anatomical comparisons of pollinated flowers ofSarcostemma subg.Ceramanthus Kuntze (New World) andSarcostemma subg.Sarcostemma (Old World) are presented.
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  • 140
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    Plant systematics and evolution 178 (1991), S. 65-94 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Rubiaceae ; Cinchoneae ; Taxonomy ; phylogeny ; cladistics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Circumscription of the tribeCinchoneae (Rubiaceae) is reconsidered on the basis of a cladistic analysis of structural data comprising 48 characters (164 states). It is concluded that the tribeCinchoneae, in order to be monophyletic, should be restricted to compriseCapirona, Cephalodendron, Cinchona, Cosmibuena, Dolicholobium, Ferdinandusa, Joosia, Ladenbergia, Macrocnemum, andRemijia. It is also suspected, on insufficient evidence, thatMaguireocharis, Pimentelia, andStilpnophyllum belong here.Alseis, Calycophyllum, Schizocalyx, andWittmackanthus form a monophyletic group possibly related to theCinchoneae. A new tribe,Calycophylleae, is proposed to accommodate them.Hillia, which is possibly the sister group of theCinchoneae, is retained in a separate tribe.Coptosapelta, Corynanthe, Crossopteryx, Hymenodictyon, Luculia, Mitragyna, Mussaendopsis, Paracorynanthe, Pausinystalia, andUncaria are referred to the same tribe, for which the nameCoptosapelteae has to be adopted. Probably alsoGreeniopsis belongs here. The generaCigarilla, Coutarea, andExostema, and possiblySyringantha andWernhamia, seem to be most closely related toPortlandia and should be transferred to the tribeCondamineeae. Bouvardia, Coursiana, Danais, Duidiana, Dunnia, Heterophyllaea, Hindsia, Lecanosperma, Manettia, Merumea, Neohymenopogon, andSchismatoclada should be provisionally transferred to the tribeHedyotideae, which is suspected to be polyphyletic, however. No conclusive results were reached concerning the position ofBalmea, Blepharidium, Emmenopterys, andSuberanthus, the position of them remaining uncertain.
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  • 141
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    Plant systematics and evolution 178 (1991), S. 247-258 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Asteraceae ; Crepis tectorum ; Genetic analysis ; geographical variation ; leaf shape
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Canonical variate analysis of plants raised in a uniform environment was used to study the pattern of geographical variation in leaf shape ofCrepis tectorum (Asteraceae). The diversity in leaf shape was much greater among populations confined to areas with exposed bedrock in the Baltic region than among weed populations scattered throughout Europe and Canada. A Ward's clustering linked outcrop populations from the archipelago of SW. Finland and the islands of Öland (Sweden) and Saaremaa (Estonia) due to the deeply lobed leaves characterizing these populations, while outcrop populations along the coast of E. Sweden were grouped due to their weakly lobed, narrow and dentate leaves. Most of the weed populations were grouped together but there was no tendency for the variation in this group to be related to habitat or geographical location. A mosaic of variation reflected in sharp (random) differentiation among local populations was superimposed on the large-scale ecogeographical pattern.—Crossing data indicated that most of the variation in degree of leaf dissection is governed by one major gene with deeply lobed leaves dominant over weakly lobed leaves. I suggest that the simple pattern of inheritance may have favoured rapid evolutionary changes in leaf shape, particularly in the Baltic area which emerged relatively late from the sea. Genetic correlations may have constrained the pattern of variation at higher taxonomic levels, since some of the trait associations detected in a segregating F2 generation were also found at the among-population level.
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  • 142
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    Plant systematics and evolution 178 (1991), S. 259-269 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Scrophulariaceae ; Paulownia taiwaniana ; P. fortunei ; P. kawakamii ; Isozymes ; morphology ; wood anatomy ; trichomes ; inflorescence grafting ; genetic analyses ; Flora of Taiwan
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Paulownia taiwaniana, the widely cultivated, commercially important tree, has been suspected of being of hybrid origin at least since its original publication in 1975. Evidence in support of this thesis, derived from a number of different investigations, is presented in this paper.—Strong evidence comes from a controlled pollination study of the two supposed parental species,P. kawakamii andP. fortunei. F1 seedlings, derived from reciprocal crosses between the suspected parents, exhibited identical banding patterns for a number of enzymes (such as SKDH, GOT, and IDH) withP. taiwaniana, when separated by electrophoresis. Furthermore, comparative morphological studies of trichomes and wood parenchyma patterns between the purported parents andP. taiwaniana reveal that this latter qualitatively exhibits characteristics that combine features of both of the suspected parental types. Biochemically, eight enzyme systems were compared in the three species here under discussion, and, without exception, the electrophoretic banding patterns exhibited byP. taiwaniana represented a combination of the alleles of the other two species. Perhaps the most convincing evidence comes from a genetic analysis of the progeny obtained by selfingP. taiwaniana. Genotypic segregation of the offspring based on a single locus each of SKDH and PGI fit the 1:2:1 hypothesis. Genotypic segregation of the offspring based on two loci each of SP and GOT fit the ratio of 3:6:3:1:2:1. This, taken in conjunction with the other data presented, clearly suggests thatP. taiwaniana is a hybrid involvingP. kawakamii andP. fortunei.
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  • 143
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    Evolutionary ecology 5 (1991), S. 231-247 
    ISSN: 1573-8477
    Schlagwort(e): Angiosperms ; pollination ; seed size
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Seed plants capture pollen before seeds are dispersed and abort unpollinated ovules. As a result, each seed is associated with an accessory cost that represents the costs of pollen capture and the costs of aborted ovules. Accessory costs may explain the minimum seed size among species, because these costs are likely to comprise a greater proportion of total reproductive allocation in species with smaller seeds. For very small propagules, the costs of pollination may not be worth the benefits, perhaps explaining the persistence of pteridophytic reproduction at small propagule sizes. The smallest angiosperm seeds are much smaller than the smallest gymnosperm seeds, both in the fossil record and in the modern flora. This suggests that angiosperms can produce pollinated ovules more cheaply than gymnosperms. Pollination becomes less efficient as a species decreases in abundance, and this loss of efficiency is greater for species with a higher accessory cost per seed. We propose that the greater reproductive efficiency of angiosperms when rare can explain why angiosperm-dominated floras were more speciose than the gymnosperm-dominated floras they replaced.
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  • 144
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Liliaceae ; Asphodelus tenuifolius ; A. fistulosus ; Cytogenetics ; electrophoretics ; morphology ; duplication genes ; speciation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The biological analysis of six populations ofAsphodelus tenuifolius and 12 populations ofA. fistulosus has confirmed that they are separate species. Both their floral structures (length of the tepals, stamens, anthers and style) and also their pollen size are clearly different.A. tenuifolius has only the 2n = 28 chromosome race, whileA. fistulosus has 2n = 28 and 2n = 56.A. tenuifolius is genetically less variable thanA. fistulosus and they have different electrophoretic mobilities. Gene duplication phenomena exist in the 2n = 28 level of both species.
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  • 145
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 169 (1990), S. 41-54 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Abutilon theophrasti ; Datura stramonium ; Panicum miliaceum ; Sorghum halepense ; Setaria faberi ; Weeds ; allozymes ; life history ; variation ; Flora of N. America
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The relationships of allozyme and life history variation in a particularly narrow ecological setting are studied. Levels of genetic variation are compared in five introduced, predominantly selfing weedy species that are undergoing rapid range expansion northward in eastern N. America, mostly in monocultures of soybean and maize. In all of these species, a low level of allozyme variation contrasts sharply with the substantial inter- and intrapopulational variation in morphological and phenological life history features. Evolutionary and historical factors, determining variability of the species examined are reviewed, including founder effects, breeding system, environmental homogeneity, polyploidy, domestication, and crop-weed interactions.
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  • 146
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Boraginaceae ; Symphytum tuberosum complex ; S. grandiflorum agg ; Chemotaxonomy ; pyrrolizidine alkaloids ; triterpenes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract InS. tuberosum subspp.tuberosum andnodosum, S. grandiflorum andS. ibericum the presence of the pyrrolizidine alkaloids lycopsamine, echimidine and symphytine could be demonstrated. The taxonS. tuberosum contains an unknown compound that seems to be specific for this taxon. This compound is not the pyrrolizidine alkaloid anadoline which has previously been reported for this species. It is possibly represented by a peak on GC/MS with a molecular ion peak at m/z 623 (as TMS derivative) and can be used as a chemotaxonomic marker for the speciesS. tuberosum. The pyrrolizidine alkaloid pattern of the two subspecies ofS. tuberosum reinforces the close relationship. Fresh material ofS. tuberosum contained the triterpene isobauerenol, but in herbarium material isobauerenol was lacking. InS. grandiflorum, neither fresh nor dried material contains isobauerenol. In herbarium material ofS. ibericum also no isobauerenol could be found. More extensive chemotaxonomical research is necessary to support the view thatS. abchasicum is more closely related toS. ibericum than toS. grandiflorum.
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  • 147
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 169 (1990), S. 97-110 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Asteraceae ; Compositae ; Inuleae ; Antennaria ; A. rosea ; Agamic complex ; agamospermy ; asexual reproduction ; clonal organism ; dioecy ; morphology ; numerical taxonomy ; phenetics ; polyploidy ; systematics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract TheAntennaria rosea polyploid agamic complex is one of the most morphologically diverse and widespread complexes of N. AmericanAntennaria. The group is taxonomically confusing because of numerous agamospermous microspecies, having been recognized as distinct species. Morphometric analyses have demonstrated that the primary source of morphological variability in the complex derives from six sexually reproducing progenitors,A. aromatica, A. corymbosa, A. media, A. microphylla, A. racemona, andA. umbrinella. Additionally, two other sexually reproducing species,A. marginata andA. rosulata, may have contributed to the genetic complexity of theA. rosea complex. Cluster analysis indicates that four discrete morphological groups exist within theA. rosea complex. Each group could be the result of predominance of genes from different groups of sexual progenitors. AsA. rosea is of multiple hybrid origin, from among several sexual progenitors, it is advisable to recognizeA. rosea as a distinct species from its sexual progenitors.
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  • 148
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Asteraceae ; Inuleae ; Antennaria ; Geographic variation ; clinal variation ; principal component analysis ; correlation coefficients
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Patterns of intraspecific variation were examined inAntennaria alborosea A. E. Porsild,A. corymbosa E. Nels,A. marginata Greene,A. microphylla Rydb.,A. parvifolia Nutt., andA. umbrinella Rydb. AlthoughA. alborosea was initially considered arctic in distribution, it became apparent that a southern montane element also exists. Our results suggest that morphological differences between arctic and southern montane specimens represent clinal variation. The additional morphological data for specimens that occur more than 1,500 km south of the species' range as it was initially described result in a better understanding of this once presumed arctic taxon. Morphological variation in the dioecious speciesA. corymbosa, A. marginata, A. microphylla, A. parvifolia, andA. umbrinella was greater between the genders than was geographic variation within each gender. These results demonstrate that both pistillate and staminate specimens must be examined in dioecious species ofAntennaria if morphological variation in the respective species is to be fully understood. Character size or number of broadly distributed species (A. microphylla andA. parvifolia) generally decreased with increasing longitude, whereas characters of species with more restricted distributions (A. alborosea, A. corymbosa, andA. marginata) generally increased in size or number with increasing latitude or longitude.Antennaria umbrinella was an exception in this respect.
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  • 149
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 169 (1990), S. 25-29 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Oxalidaceae ; Oxalis tuberosa alliance ; Chromosome numbers ; karyotype analyses ; cytotaxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Twelve taxa of theOxalis tuberosa alliance were analysed and found to share the same basic chromosome number x = 8. The karyotypes are composed by small metacentric and submetacentric chromosomes. Different ploidy levels were found among the taxa: there were 9 diploids, 1 tetraploid, 1 hexaploid and 1 octoploid. The last ploidy level corresponds toO. tuberosa, the only tuber bearing taxon found so far in the alliance. Cytotaxonomic evidence and evolutionary considerations suggest to classify theO. tuberosa alliance in sect.Herrerea.
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  • 150
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 169 (1990), S. 65-68 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Boraginaceae ; Onosma gigantea ; Trichodesma africana ; Trichodesma boissieri ; Buzz-pollination
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Buzz-pollination was observed in three nectariferousBoraginaceae spp.:Onosma gigantea Lam.,Trichodesma africana (L.)R. Br. andT. boissieri Post. An evolutionary pathway from usual nectariferous flowers to typical buzz-pollinated flowers is suggested.
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  • 151
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 169 (1990), S. 81-96 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Gramineae ; Festuceae ; Dactylis glomerata ; Enzymatic markers ; phenology ; interploid exchanges ; autopolyploidy ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Phylogenetic relationships between sympatric, morphologically indistinguishable diploid and tetraploid plants ofDactylis glomerata L. (Gramineae) in Galicia (Spain) were assessed using allozyme markers for 6 distinct systems. The study exploited recent introduction in Galicia and subsequent hybridization of an alien 4xDactylis subspecies possessing distinct allozymes from those of all the native plants. Opportunities for gene exchanges between the ploidies were estimated from in situ observations of flowering, examination of progenies in 2x/4x natural and experimental crosses, and enzyme analyses. Results show a high genetic similarity between the Galician diploids and tetraploids, which possess peculiar alleles in common. Although the ploidy levels usually have distinct flowering periods, interploidal crosses do occasionally occur. Gene flow is likely much more important from the diploid to the tetraploid level. A good genetic intermixing occurs between the Galician and the alien tetraploid entities which have simultaneous flowering. Autopolyploidization of the diploids followed by various rates of hybridization is proposed as one very probable origin of natural tetraploids inDactylis.
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  • 152
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Asteraceae ; Inuleae ; Antennaria alborosea ; A. corymbosa ; A. marginata ; A. microphylla ; A. parvifolia ; A. rosea ; A. umbrinella ; Taxonomy ; multivariate morphometrics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Multivariate analysis of vegetative and reproductive characters was used to examine morphological relatedness amongAntennaria alborosea A. E. Porsild,A. corymbosa E. Nels.,A. marginata Greene,A. microphylla Rydb.,A. parvifolia Nutt.,A. rosea Greene, andA. umbrinella Rydb. Both pistillate and staminate plants were examined. Some of the characters examined were variable in one species, but stable in another (i.e., presence or absence of papillae on the achenes). Our analyses indicate that the seven species are morphologically distinct. It is hypothesized that theA. rosea agamic complex arose through hybridization amongA. corymbosa, A. microphylla, A. umbrinella, and possiblyA. dioica (L.)Gaertn. However, hybridization between the three former species and others, as well as their subsequent morphological responses to different environmental conditions causes confusion in recognizing the taxa.Antennaria angustifolia Rydb.,A. arida E. Nels.,A. confinis Greene,A. scariosa E. Nels.,A. foliacea humilis Rydb.,A. concinna E. Nels., andA. viscidula E. Nels. are considered to represent F 1 hybrids.
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  • 153
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 170 (1990), S. 37-51 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Valerianaceae ; Transfer cells ; lignification ; lipid droplets ; oil cells ; tannins ; Development ; structure ; axial distribution ; transmission electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Development, structure and the axial distribution of transfer cells and their lignification were investigated inValerianella locusta, Valeriana officinalis, andV. tuberosa (Valerianaceae). Fundamental new results are: (1) Transfer cells often contain numerous lipid droplets. Within the stem the distribution of cells containing lipid droplets correlates to that of transfer cells. (2) InValeriana officinalis persisting protuberances are frequently found on pit membranes of xylem transfer cells. Lignified transfer cells can undergo a second modification: a layer covering the secondary wall forms wall ingrowths similar to those of transfer cells. (3) Peripheral pith cells, abuting transfer cells, are able to modify into transfer cells. Cambial derivatives are only temporarily developed as transfer cells. (4) Phloem transfer cells are found in vascular bundles of the whole axis. (5) In roots, xylem transfer cells are poorly developed or absent. (6) Oil cells with oil bodies are present in the rape ofValeriana tuberosa. They are absent however in the stem of the species investigated. (7) Tannins occur in elements of the primary cortex, phloem and secondary xylem ofValeriana officinalis.
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  • 154
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 169 (1990), S. 237-243 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Asteraceae ; Heliantheae ; Ambrosia ; Anther ; crystals ; pollen ; sperm cells ; tapetum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Staminate flowers of giant ragweed,Ambrosia trifida L. (Asteraceae, tribeHeliantheae, subtribeAmbrosiinae) were processed into resin and sectioned 1–2 µm thick. The invasive (amoeboid) anther tapetum remains parietal until microspores are released from tetrads, then it swells and invades the locule, merging gradually into a single protoplast that flows among the microspores. After the tapetal membrane ruptures at late microspore stage, tapetal debris fills the locule, then disappears as pollen matures. Pollen becomes tricelled before anthesis. The two sperm cell nuclei are slender and wormlike. The present report supports the two generalizations that invasive tapetum and tricelled pollen are attributes of theAsteraceae.
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  • 155
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 170 (1990), S. 205-214 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Polemoniaceae ; Pollen ; ovule ratio ; stigmatic pollen germination ; breeding systems
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Pollen — ovule ratios and percentages of stigmatic pollen germination (SPG) were measured for over 160 taxa of thePolemoniaceae. When related to taxa with known breeding systems, it is found that low SPGs and high P:O ratios characterize xenogamous plants, high SPGs and low P:Os characterize autogamous plants. There is a significant negative correlation between P:O ratio and SPG in the whole family as well as in certain genera. Both measures can serve as reliable indicators of the breeding systems in taxa of thePolemoniaceae and can be measured in dried or living specimens. Accordingly, most polemons feature “mixed” breeding system, i.e. facultative xenogamy or facultative autogamy. Xenogamy is common among the tropical genera and in theLeptodactylon, Phlox andPolemonium. Autogamy is more frequent in the tribeGilieae (particularly inGilia) than in the other tribes. Annual taxa tend to be autogamous, showing on the average higher SPG and lower P:O ratio. The lepidopteran-pollinated group of species have a higher mean P:O ratio and lower mean SPG thus indicating that such plants are associated with crosspollination more than the others.
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  • 156
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 170 (1990), S. 215-228 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Compositae ; Eupatorium ; Chromosomal distance ; chromosomal identity ; karyotype analysis ; statistics phenetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Somatic metaphase karyotypes were analyzed for 22 diploid species ofEupatorium. The karyotypic comparisons were made using two indices: minimal chromosomal distance (MCD), measuring overall dissimilarities, and chromosomal identity (CI), measuring number of morphologically identical chromosomes between species. The resulting phenograms from these indices are largely compatible. The 22 species cluster into four groups in the phenogram using MCD, and the grouping corresponds well with morphology or geographic distribution into the three N. American groupsEutrochium, Uncasia, Traganthes, and the E. Asian group. These results suggest that karyotypes in perennialEupatorium have been considerably conservative and changed not through large chromosomal mutations but through small chromosomal mutations gradually fixed.
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  • 157
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Scrophulariaceae ; Striga hermonthica ; Hemiparasitism ; hostspecificity ; enzyme electrophoresis ; genetic diversity ; Flora of Burkina Faso ; Sudan
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Striga hermonthica is a root hemiparasite that attacks onlyGramineae, includingSorghum and millet for which it is a principal cause of lowered yield. Enzyme electrophoresis was used to investigate genetic diversity inStriga hermonthica and to determine the level of differentiation between host-specialized populations. Nine genetic loci coding eight enzymes were interpreted and data obtained from three populations: oneSorghum-adapted population from Sudan and two populations from Burkina Faso, oneSorghum-adapted and the other millet-adapted. Levels of polymorphism were similarly high in all three populations (P=0.625, A=2.6−2.8, H=0.293−0.401). Genotypic frequencies at most loci conformed to Hardy-Weinberg expectations in each population, consistent with outcrossing as predicted from previous studies of floral biology. Occasional heterozygote deficiencies were probably the result of Wahlund effect. The mean value of FST over the three populations was 0.068, indicating a slight to moderate level of genetic differentiation among the populations. The two Burkina Faso populations were more closely related (S=0.940, D=0.006) than either was to the Sudan population, suggesting that geographic separation is more important than host specialization in contributing to population differentiation. TheSorghum-adapted population was slightly closer to the Burkina FasoSorghum-adapted population (S=0.873, D=0.047) than to Burkina Faso millet-adapted population (S=0.851, D=0.074). The absence of substantial genetic divergence between host-specific populations ofStriga could result either from recent evolution of host-specialized strains or from strong selection for physiological specialization in the face of substantial gene flow between the populations.
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  • 158
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 169 (1990), S. 209-217 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Compositae ; Silybum marianum ; Formicidae ; Messor semirufus ; Myrmecochory ; preadaptations ; synanthropic plant ; grasslands
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The common Mediterranean ruderal thistleSilybum marianum is associated with nutrient-rich sites. Its wind-dispersed achenes possess an oily food body, that is attractive to harvester-ants. Following removal of the oily body, the achenes are deposited in the refuse zone together with rich organic material and soil removed from the nest; while in the nest the achenes are partly protected from fires. The thistle grows successfully in the nutrient-enriched refuse zone and thus dominates patches in the grassland. Preadaptations to live in association with harvester-ants enableS. marianum to occur also on marking stations of male gazelle, on cattle dung deposits, and in synanthropic ruderal habitats.
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  • 159
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 169 (1990), S. 219-235 
    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.
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  • 160
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 169 (1990), S. 245-259 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Potamogetonaceae ; Potamogeton distinctus ; P. indicus ; P. nodosus ; P. tepperi ; Taxonomy ; distribution ; description
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Potamogeton distinctus has an E. Asian distribution and is closely related toP. nodosus. P. tepperi seems to be a synonym ofP. tricarinatus, even though the name has frequently been applied to other species likeP. distinctus. P. indicus is a synonym ofP. nodosus notwithstanding the fact that not all Indian broad-leaved pondweeds belong to that taxon.
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  • 161
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 170 (1990), S. 29-35 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Balanophoraceae ; Balanophora ; Hachettea ; Langsdorffia ; Lophophytum ; Scybalium ; Thonningia ; Stomata ; epidermal surface
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Both adaxial and abaxial leaf surfaces were searched for stomata inBalanophora elongata, B. fungosa, Hachettea austro-caledonica, Langsdorffia hypogaea, Lophophytum mirabile subsp.mirabile, Scybalium jamaicense, andThonningia sanguinea (Balanophoraceae). Neither stomata nor guard cells were observed. The epidermal surfaces of these species are extremely diverse with respect to cell shape, cell size, and surface ornamentation, these features providing valuable systematic criteria.
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  • 162
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Asteraceae ; Taraxacum sect.Ruderalia ; Sexual diploids ; mixed populations ; distribution pattern ; ecogeographical relations ; taxonomical problems
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Herbarium specimens (c. 1 000) and population samples (76) have been screened for the occurrence of diploid representatives ofTaraxacum sect.Ruderalia (T. sect.Vulgaria, nom. illeg.). The area studied comprises German Democratic Republic, Poland, Czechoslovakia, Hungary and parts of Austria, Yugoslavia, and Rumania. Diploids are common from the Valley of the Moravia river on southwards. Isolated outpost localities are found in S. Poland and extend far to the north: neighbourhood of Berlin. Based on the pattern of distribution in Czechoslovakia, the Pannonian (thermophilous) phytogeographical character of the diploids is discussed. Special attention has been paid to morphological differences between di- and triploids in Czechoslovakia. The study provides a basis for further biosystematical and taxonomic studies in the relationships between diploids and polyploids as well as in the stability of agamospecies.
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  • 163
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 169 (1990), S. 177-207 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Orchidaceae ; Ophrys ; bees ; Melecta ; Eucera ; Anthophora ; Andrena ; Pollination ; pseudocopulation ; Flora of Cyprus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In the southern part of Cyprus the pollinator —Ophrys (Orchidaceae) relationships and its specifity have been investigated from the end of February until the middle of March 1986. 12Ophrys spp. were found. To date, only a single pollinator reference has been reported from this island. We found the following pollinators:Melecta tuberculata (Ophrys kotschyi),Eucera dimidiata (Ophrys flavomarginata),Eucera gaullei (Ophrys umbilicata),Eucera paulusi (Ophrys bornmuelleri),Anthophora erschowi (Ophrys elegans),Andrena torda (Ophrys sicula =O. lutea subsp.minor),Andrena cinereophila (Ophrys fusca, small-flowered),Andrena flavipes (Ophrys israelitica),Andrena morio (Ophrys iricolor andOphrys transhyrcana),Andrena bimaculata (Ophrys sphegodes aggr., probably formerly confused withO. transhyrcana). Most interestingly, it could be verified thatO. flavomarginata/O. umbilicata, O. bornmuelleri/O. levantina andO. transhyrcana/O. sphegodes aggr. (possiblyO. sintenisii) are different biospecies. This is a result of genetic isolation due to varying pollinators, and of differences in flower morphology.
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  • 164
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 170 (1990), S. 193-204 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Solanaceae ; Physalis ; Hair morphology ; systematics ; hair development
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Hair morphology was exammed on developing seedlings and mature plants of ten species from five of seven series inPhysalis. The taxonomic importance of hair development and the distribution of hair types then was evaluated with respect to other comparative data. Two classes of hair types were observed, as found in earlier investigations ofSolanum andRhododendron. The first hair class comprises a sequence from unbranched hairs to dendroid-stelliform hairs. Hairs of this class show considerable variability among taxa in size, presence or absence of glandular tips, and presence and degree of branching, and so were useful in making taxonomic comparisons. The second hair class consists of short hairs, each tipped with a multicellular gland. This second hair class was not useful taxonomically because of its lack of variability in morphology and its often rare occurrence on a plant. The taxa studied exhibit distinctive trichome features which serve to distinguish series and, in some cases together with other data, provided new insight into previously enigmatic species relationships.
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  • 165
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 170 (1990), S. 229-236 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Asteraceae ; Emilia ; Chromosome numbers ; C-banding ; cytogeography ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Analysis of several populations in a large part of the distribution area of the genusEmilia in Brazil has revealed only two species: the diploidE. sonchifolia and the tetraploidE. fosbergii. The more widely reportedE. coccinea was not found. They show a karyotype constancy in morphology and chromosome number (2n = 10 and 2n = 20, respectively), C-banding pattern and number of secondary constrictions. Some indications were found thatE. fosbergii may be an allopolyploid and that its ancestors had different genome sizes.
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  • 166
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 170 (1990), S. 237-245 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Annonaceae ; Polyalthia littoralis ; Extended spiral thickenings ; flowering phenology ; reproductive biology ; self-pollination ; Malesian tropics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Flowering phenology of some annonaceous trees and reproductive biology ofPolyalthia littoralis (Annonaceae) were studied. The trees showed various types of flowering phenology within the family. Among them,P. littoralis had hermaphroditic and protogynous flowers, and exhibited continuous flowering throughout the year. Bagged flowers set fruits and seeds comparable to the control. The observations of meiotic stages and the results of castrated tests indicated no possibility of apomictic reproduction. The abscised anthers attached to torus by the extended spiral thickenings, and accomplished self-pollination. Outbreeding possibly occurs, but the following self-pollination guarantees seed set.
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  • 167
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 171 (1990), S. 57-88 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Inflorescence ; pseudanthium ; pseudocorolla ; flower symmetry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Pseudanthia occur in more than 40 angiosperm families. With regard to the underlying inflorescence structure they can be classified into the following groups: (a) floral and (b) hyperfloral pseudanthia, each with (c) or without (d) pseudocorollas. Pseudanthia have developed along independent evolutionary lines and are not bound to a particular inflorescence structure. They are the result of (a) the specific morphological predisposition of the taxon concerned, (b) aggregation and diminution of the flowers, giving rise to the formation of an attraction unit (for animal pollination), (c) variation, and (d) selection. Ontogenetical abbreviation is regarded to play an essential role in the origin and elaboration of pseudanthia.
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  • 168
    Digitale Medien
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    Plant systematics and evolution 171 (1990), S. 1-14 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Compositae ; Chemistry ; systematics ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The broad knowledge of the chemistry of theCompositae allows the discussion of its relevance for the systematics and evolution within the family. Furthermore a separation into subfamilies can be supported by the observed differences in the distribution of the main constituents in the tribes.
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  • 169
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 170 (1990), S. 247-255 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Mimosaceae ; Schrankia nuttallii ; Halictidae ; Bee-pollination ; anthecology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Schrankia nuttalii flowers through late spring on the tallgrass prairie. Although each stem produces an average of 26 capitate inflorescences only 12% of those inflorescences will open each day to disperse and receive polyads. Each inflorescence may live up to 48 hours but anthers abscise by late afternoon on the first day and the filaments change color and lose their scent. The 78–93 florets comprising each inflorescence open synchronously before dawn or during early morning hours. First day inflorescences ofS. nuttallii are herkogamous and fragrant. They are nectarless. Bombyliid flies and male bees are infrequent floral foragers so the major pollinators include female bees representing five families;Anthophoridae, Apidae, Colletidae, Halictidae, andMegachilidae. All foraging insects ignore second day inflorescences although stigmas are still receptive. Although 97% of all bees collected onS. nuttallii carrySchrankia polyads in their scopae or corbiculae 59% also carry the pollen/pollinaria of one or more coblooming angiosperms. At least 98% of all bees carrying mixed pollen loads incorporate the pollen/pollinaria of one or more nectariferous taxa (e.g.Asclepias spp.,Asteraceae, Convolvulaceae, Delphinium spec., etc.). Species of halictid bees are more likely to carry pure loads ofS. nuttallii polyads (70%) than bees of the four remaining families. Due to the nectarless florets and high degree of polylectic foraging bee-pollination inS. nuttallii converges more closely with the pollination systems of some AustralianAcacia spp. than with most other xeric/tropical genera of mimosoids studied in the western hemisphere.
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  • 170
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 171 (1990), S. 27-55 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Theales ; Medusagynaceae ; Medusagyne ; Systematics ; anatomy ; pollen ; morphology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The comparative vegetative and reproductive morphology and anatomy of the endangered, monotypic, dicotyledonous genusMedusagyne was studied, and detailed descriptions of leaf, axis, nodal, wood, floral, pollen, fruit, and seed structure are presented. Overall, the genus has many specialized features, including the possession of extreme, habitat-related specializations. Flowers are either bisexual or staminate, and are interpreted as retaining some primitive aspects, such as many free parts spirally arranged on an elongate floral axis. One of the most salient structural features of the plant is the massive development of ensheathing fibrous elements around the vascular system of both vegetative and reproductive tissues. Diffuse foliar sclereids are absent. Particular attention is paid to the unusual multicarpellate, synovarial gynoecium and comparisons are made with theCaryocaraceae. The totality of morphological and anatomical evidence confirms the view thatMedusagyne is a very distinct and evolutionarily isolated genus, best treated as forming the monotypic familyMedusagynaceae. Observations are presented, including the occurrence of stamen fascicle traces, that link the family to the dillenialean and thealean assemblage. Like other isolated thealean taxa,Medusagyne shows affinities to several different families, without having especially close relationships with any particular extant taxon.
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  • 171
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 171 (1990), S. 117-128 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Asteraceae ; Cardueae ; Onopordum nervosum ; Carthamus arborescens ; Cirsium scabrum ; Life cycle ; adaptive strategies ; autoecology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The life cycle and autoecology of three Mediterranean thorny species,Onopordum nervosum (Iberian endemic),Cirsium scabrum (Western Mediterranean) andCarthamus arborescens (Iberian-North African), of potential use in agriculture as bioenergetic, forage or oil producing plants were studied. These threeCardueae spp. are good examples of ways in which Mediterranean plants adapt their typical annual cycle to avoid summer droughts.O. nervosum is a perennial, monocarpic, heliophilous species which flowers in early summer and grows even under the extreme xeric conditions of the Mediterranean summers. It is a basiphilous plant usually found in sandy-loamy and sandy-clayey-loamy soils with a marked geographical variability in its seed germination.C. scabrum is a perennial, monocarpic species which has a long life cycle, flowering in summer and growing only during the wet months. It is not well-adapted to droughts and is usually restricted to acid soils.C. arborescens is a perennial, polycarpic species which flowers in spring and dries up in summer. It is usually found in basic loamy-sandy or sandy-loamy soils poor in organic matter.
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  • 172
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Iridaceae ; Iris pumila ; Phenotypic plasticity ; morphological variation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Variation patterns in phenotypic plasticity and broad sense heritability of 26 characters were examined within and among closely adjacent habitats of the bearded iris,Iris pumila. It was found thatI. pumila has considerable differentiation for phenotypic plasticity and genetic variation over short distances. An analysis of relationships between character differentiation and phenotypic plasticity suggests that they could have evolved independently. Possible mechanisms for maintaining local differentiation of the observed plastic and genetic variation are also discussed.
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  • 173
    Digitale Medien
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    Plant systematics and evolution 170 (1990), S. 53-70 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Potamogetonaceae ; Potamogeton malaianus ; P. sumatranus ; P. wrightii ; Description ; distribution ; taxonomic evaluation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The type specimens ofP. malaianus Miquel collected byTeijsman are not identical withP. wrightii Morong, a species calledP. “malaianus” in Japan and elsewhere; they belong toP. nodosus. As a possible candidate for the correct name,P. sumatranus Miquel was studied: its exact identity, however, cannot be proved beyond doubt, even though the name refers at least partly toP. wrightii. That is whyPotamogeton wrightii Morong is proposed as the valid name of the species. A thorough description is provided including data on anatomy, morphology, life history, variability and ecology. A complete list of specimens, of synonyms and of misidentifications is given as well. The species shows a fuzzy structure with several special forms, intergrading hybrids; it is closely related with other taxa likeP. sumatranus. Still a great number of specimens cannot be assigned with certainty to any taxon.
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  • 174
    Digitale Medien
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    Plant systematics and evolution 170 (1990), S. 97-106 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Gentianaceae ; Lisianthius ; Population variation ; ribosomal DNA ; isozymes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Restriction endonuclease fragment analysis of nuclear ribosomal DNA (rDNA) was completed on 25 individuals each from seven populations of theLisianthius skinneri (Gentianaceae) species complex in Panama. Seven restriction enzymes were used to determine the amount and type of rDNA variation within and among individuals of the populations. No restriction site variation was seen within populations or individuals although site differences were seen among populations. Spacer length variation within and among individuals of populations was mapped to the internal transcribed spacer (ITS) region between the 18S and 5.8S rRNA genes, a region inLisianthius rDNA that previously was shown to exhibit length differences among populations. This is the first reported case of such variation within and among individuals of populations for the ITS region. Presence or absence of ITS spacer length variation is not correlated with levels of isozymic heterozygosity within populations. No detectable length variation within individuals or populations was seen in the larger intergenic spacer (IGS). Although populations varied with respect to IGS length, all individuals of a given population had a single and equivalent IGS length.
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  • 175
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 172 (1990), S. 65-75 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Rosaceae ; Rubus ; Chloroplast DNA ; restriction fragment length polymorphism ; cladistic analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The variability in chloroplast DNA type of 20Rubus genotypes was examined by Southern hybridization. DNA extracted from theRubus accessions was digested with two restriction enzymes (EcoRI and EcoRV) and heterologous chloroplast DNA sequences from barley and pea were used as probes to detectRubus chloroplast DNA sequences on Southern blots ofRubus total DNA. Restriction fragment length polymorphism was detected and a total of 92 restriction fragments were generated by the probe/enzyme combinations examined. Cladistic principles based on the parsimony assumption were used to assemble a phylogenetic tree based on chloroplast restriction fragment length data. The phylogenetic tree grouped the taxonomically defined species and is in general agreement with information based on morphological criteria. However, the Japanese red raspberryR. illecebrosus was shown to have diverged considerably in terms of evolutionary time from other species in subg.Idaeobatus. Furthermore, the molecular approach provides a quantitative estimate of the relationship between species that is difficult to obtain from morphological data. In order to complement the chloroplast DNA information a ribosomal DNA probe was also included in the analysis and provided further information on the phylogenetic relationships withinRubus.
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  • 176
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    Plant systematics and evolution 169 (1990), S. 13-24 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Poaceae ; Triticum araraticum ; Karyotype ; C-banding ; intraspecific divergence
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract DifferentTriticum araraticum lines were studied by C-banding method. The intraspecific divergence ofT. araraticum was shown to be caused mainly by large chromosomal rearrangements. Two main chromosomal types were distinguished among the studied lines: (1) a karyotype similar to that ofT. timopheevii and (2) different one. The first type includes some lines ofT. araraticum subspp.kurdistanicum andararaticum; the second comprises most lines ofT. araraticum subsp.araraticum. The lines of the first type can give fertile F1 hybrids withT. timopheevii.
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  • 177
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 169 (1990), S. 55-63 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Gesneriaceae ; Monophyllaea ; M. hirtella ; M. horsfieldii ; Chromosome number ; hybridization ; fertility ; tropical rain forest ; habitat segregation ; Flora of Indonesia ; Sumatra
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A natural hybrid (2n = 21) between the parapatric rain forest speciesMonophyllaea hirtella (2n = 20) andM. horsfieldii (2n = 22) (Gesneriaceae) has been observed at Sg. Lubuk Paraku, Padang, W. Sumatra. The hybrids showed intermediary characters between the parental species in the inflorescence structure, flower size and colour, indumentum, chromosome numbers, and habitat. The 29% pollen fertility of a single hybrid specimen suggests that the genetical isolation between the parental species may break down and reproduction over subsequent generations may occur.
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  • 178
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 169 (1990), S. 69-80 
    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.
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  • 179
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 169 (1990), S. 111-121 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Aesculus californica ; Amsinckia lunaris ; Brodiaea pulchella ; Carduus pycnocephalus ; butterflies ; Battus philenor ; Heliconius ; Pollen amino acids ; diffusion ; nectar ; butterfly-feeding
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The increase of the amino acid concentration over different time intervals in artificial nectar (i.e., a sucrose solution) due to pollen contamination was investigated in four Californian plant species (Aesculus californica, Amsinckia lunaris, Brodiaea pulchella, Carduus pycnocephalus), which are important nectar resources for a Californian colony of the butterflyBattus philenor as well as for other insects. The increase of the amino acid concentration in the medium is different in all four species and seems to be determined by a variety of factors including permeability of the pollen grain wall and presence or absence of pores. The results suggest a passive diffusion process of the free pollen amino acids into the medium rather than an active release. Implications from the experiments forBattus philenor and for other nectar feeding pollinators are discussed. A possible complementary effect of free pollen and nectar amino acids is proposed for plant species in which pollen is likely to be knocked into nectar by their flower visitors. A possible evolutionary pathway from nectar feeding butterflies such asBattus philenor to the complex derived pollen feeding habit in theHeliconius butterflies is proposed.
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  • 180
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 170 (1990), S. 11-27 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Orchidaceae ; Thelymitra epipactoides ; bees ; Nomia ; Lasioglossum ; Pollination ; deceit ; floral mimicry ; Flora of Australia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Thelymitra epipactoides has a highly variable visual display achieved through polychromatic flowers and variable inflorescence size, bearing between 7 and 31 flowers, which attract foraging polylectic bees. Only bees of the genusNomia were observed carrying pollinia and successfully pollinating the orchid. The genusNomia contains polylectic, pollen gathering species that store pollen in both the crop and scopa on the hind legs. The absence of a reward for the bees indicates the orchid is relying on deception to attract visitors. The relationship of deception to mimicry is discussed. Once on the flower, tactile, visual and possibly olfactory stimuli direct bees to the false anther formed by the voluminous column wings, where morphological adaptations of the flower ensure that the pollinarium is deposited on the gaster of the bee to effect pollination. — The lack of seed set observed on the Victorian coast appears to be due to the absence of pollinators from the heath and grassland communities in which the orchid grows. This may well be a consequence of the reduced number of plants flowering in the community (a result of the elimination of fire at these sites), thus not maintaining a floral community attractive to potential pollinators.
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  • 181
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 170 (1990), S. 125-132 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Caryophyllaceae ; Dianthus gratianopolitanus ; Pollination ; psychophily ; phalaenophily ; nectar composition
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Pollination ofDianthus gratianopolitanus was studied in a population of the Swiss Jura mountains. Pollinators of this plant species are reported here for the first time. The flowers were not only visited by butterflies as postulated in the literature, but also by diurnal hawkmoths (Macroglossum stellatarum) and by diurnal and nocturnal noctuid moths. — Nectar is sucrose-dominant, the sugar concentration is moderate but the amino acid concentration is high. Nectar characteristics correspond well with the syndrome ofLepidoptera-pollinated flowers. — Field observations and flower characters (colour, range of the calyx length) suggest thatDianthus gratianopolitanus is an intermediate species in the transition of butterfly to moth pollination. — Lack of reproductive success inDianthus gratianopolitanus can not be attributed to lack of suitable pollinators.
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  • 182
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Rubiaceae ; Ixora ; I. platythyrsa ; Moth-pollination ; secondary pollen presentation ; Flora of Madagascar
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The pollination biology ofIxora platythyrsa (Rubiaceae) was studied in NW. Madagascar. The plant displayed cream-yellow, nocturnally fragrant, nectariferous, tubular and strongly protandrous flowers. These had an “ixoroid” secondary pollen presentation mechanism: prior to anthesis, anthers exhausted their pollen onto unripe stylar heads. From this position pollen of male-stage flowers later adhered to primarily the probosces of small visiting nocturnal noctuid and geometrid moths. — Pollen was subsequently raked off moths' probosces by receptive, copiously papillose stigmas of female-stage flowers. Principal pollination adaptation was probably to the noctuid moth subfam.Sarrothripinae.
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  • 183
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    Plant systematics and evolution 171 (1990), S. 129-134 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Balanophoraceae ; Balanophora ; Tuber surface morphology ; systematics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The surface ofBalanophora tubers consists of a nonepidermal layer made up of two distinctive types of cells, armature cells and stellate wart cells. Both cell types are provided with a heavy wall, and are dead at maturity. Stellate warts in the three species investigated,B. elongata, B. fungosa, andB. hansenii, séem to be uniform in appearance, but armature cells are extremely distinctive for each species. They are present in large, agglomerate masses in the first, singly or in very small clusters in the second, and as completely free, individual, acicular cells in the third species. Such differences are believed to be significant systematically, and the separation ofB. hansenii is thus probably justified. Notwithstanding superficial similarities, stellate warts do not seem to be comparable to the lenticels of other plants.
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  • 184
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    Plant systematics and evolution 171 (1990), S. 205-220 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Poaceae ; Secale ; Ribosomal DNA ; spacer subrepeats ; restriction fragment length polymorphism (RFLP) ; phenetic relationships
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Variation in ribosomal DNA spacer length was analysed in 23 populations of 12Secale spp. by restriction enzyme analysis. Digestion of rDNA with Taq I endonuclease enzyme yields spacer fragments that include the subrepeat array and the non-repetitive region downstream of the array. Extensive spacer length variation existed in most species with Taq I fragment lengths ranging from 0.9–3.1 kb. These length variants have been attributed to the differences in number of 134 bp spacer subrepeats within rDNA arrays.S. silvestre was the only species to exhibit a unique spacer length variant of 0.9 kb and this was shown to result from the presence of an extra Taq I site in the spacer. rDNA spacer length frequencies were determined for the species. These frequencies were used to derive phenetic relationships between the species by numerical taxonomic methods. In plots constructed fromGower's distance matrices,S. silvestre appeared well separated from the major cluster consisting of the other species. On the basis of morphological and cytogenetic criteria,S. silvestre is considered the most ancient species. The rDNA data is consistent with this interpretation as it shows a clear differentiation ofS. silvestre from all the other species based on length and nucleotide sequence composition of the spacer region.
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  • 185
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Poaceae ; Sorghum vulgare ; great millet ; DNA hybridization ; repetitive DNA
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The 1.4 kbp Xba I and the 1.3 kbp EcoRI repeat families in great millet were partially characterized with respect to their genomic distribution and their homology with the EcoRI and Xba I families of five other millet DNAs. The digestions of great millet DNA using increasing amounts of the two enzymes show that these two families are disperse in nature. The hybridization of these two families to the genomic digests of great millet indicates that they are arranged in a clustered and scrambled manner. Similarly, the hybridization with the EcoRI and Xba I digests of five other millet DNAs reveals the speciesspecific nature of these two repeat families. The latter also hybridize to the total repetitive fraction of great millet isolated at a highly stringent temperature of 75°C suggesting that the members of these two families are probably largely homogeneous.
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  • 186
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    Plant systematics and evolution 171 (1990), S. 147-155 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Oxalidaceae ; Oxalis violacea ; Andrenidae ; Bombyliidae ; Halictidae ; Megachilidae ; Pollination ecology ; heterostyly
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Vernal grass fires may encourage profuse flowering in clonal, colonies ofOxalis violacea. Long-styled colonies appear to be more floriferous than short-styled colonies and set a greater number of capsules. Individual flowers of both morphs live one or two days, change position on their respective pedicels and advertise nectar concealed at the base of the floral throat. AlthoughDiptera, Hymenoptera, andLepidoptera forage for nectar, bees (Andrenidae,Anthophoridae, Halictidae, andMegachilidae) probably make the only effective pollen transfers between the two morphs. Both male and female bees may transport pollen of both morphs and short-tongued bees (e.g.,Augochlorella spp.,Dialictus spp.) may be more common but as effective as pollinators as long-tongued bees (e.g.,Calliopsis andreniformis andHoplitis spp.). The conversion rate of flowers into capsules is only 13–17%. The spreading style in the short-styled morph is interpreted as an adaptation restricting insect-mediated, self-pollination but encouraging bee-stigma contact during nectar foraging.
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  • 187
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    Plant systematics and evolution 171 (1990), S. 187-197 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Aceraceae ; Acer ; Sympodial and monopodial branching ; evolution ; adaptive strategy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The evolutionary trend and its ecological implications in sympodial and monopodial branching patterns has been investigated in 20 JapaneseAcer spp. through comparison of shoot tip abortion and terminal bud formation. The genus is divided into two species groups according to its branching pattern, one (6 species) predominantly exhibiting sympodial branching with frequent monopodial branching in short shoots (sympodial species), and the other (14 species) exhibiting only monopodial branching (monopodial species). The early ontogeny of leaf and bud scales is described. Despite the difference in branching patterns, the bud scales of terminal buds are essentially the same in having a leaf base developed to function as a protecting organ. In all the sympodial species, during the abortion of a sympodium shoot tip, one or two pairs of primordia were found to occur on the apex, and later wither. These primordia resemble bud scales of terminal buds in their ontogeny and morphology, and appear to be rudimentary. It is suggested that a rudimentary terminal bud develops together with the establishment of sympodial branching, and that sympodial branching has originated from monopodial branching. Based on this proposed evolutionary trend, it is suggested thatAcer has moved from less shady habitats into shady habitats with monopodial branching (advantageous for vertical growth) changing into sympodial branching (advantageous for lateral spread).
    Materialart: Digitale Medien
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  • 188
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 171 (1990), S. 233-248 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Compositae ; Lactuca sativa ; L. serriola ; L. saligna ; L. virosa ; Hybridization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The degree of relationships withinLactuca sativa and three wild relativesL. serriola, L. saligna, andL. virosa was studied by observing the performance, vigour and fertility of the F 1 hybrids obtained from crosses made in and between the four species. The crosses ofL. saligna ×L. virosa and the reciprocal crosses produced no hybrids.L. saligna andL. virosa are the least related of the four species.L. sativa ×L. serriola and the reciprocal crosses were successful and produced fertile hybrids These two species are genetically very closely related.L. saligna is known to produce, as a female parent, hybrids withL. sativa andL. serriola. Now the reciprocal cross was successful for the first time, so the unability to obtain hybrids in the past was based on the choice of accessions and not caused by unilateral incompatibility.L. virosa ×L. sativa and the reciprocal combination produced hybrids. The combinationL. serriola ×L. virosa produced hybrids with very limited fertility. In contrast to earlier reports (sterile hybrids) one combination of the reciprocal cross too produced hybrids with very limited fertility.—Some of theL. saligna ×L. sativa (and reciprocal) hybrids were found to look strikingly likeL. serriola. This adds evidence for the descent ofL. serriola andL. sativa:L. saligna also made part of the ancestral complex of the cultivated lettuce.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 189
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 170 (1990), S. 107-124 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Betulaceae ; Alnus ; Isozymes ; population genetics ; hybridization ; genetic distance ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The actinorhizal genusAlnus contains numerous taxa that have been morphologically classified into different subgenera, species and subspecies. The genetic divergence has been evaluated within subg.Alnobetula between the parapatric taxaAlnus sinuata andA. crispa, using diversity of allozyme markers at 15 structural loci among 20 populations. Evidence for introgressive hybridization at the overlap of their ranges was noted in three populations. However, the width of the hybrid zone appeared tenuous. The average genetic distance derived from the comparisons of conspecific populations was much smaller than the interspecific distance (D = 0.047). This allelic divergence was also paralleled with larger amounts of allelic and genotypic diversity within and among populations ofA. sinuata, which are occupying a more heterogenous ecological niche. It is proposed that the repeated advances and retreats of the ice sheet during the Pleistocene may have promoted the divergence and allopatric evolution of these subspecies, and that secondary contact may have occurred repeatedly during the interglacial periods. The dynamic-equilibrium model would predict in such cases that narrow hybrid zones, formed at the contact of parapatric ranges, would impede gene exchange between parental taxa by selection against hybrids. The results obtained in this study seemed concordant with this hypothesis, as they were also in agreement with the existent taxonomical treatment of these taxa based on morphology.
    Materialart: Digitale Medien
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  • 190
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 170 (1990), S. 151-159 
    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
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  • 191
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 170 (1990), S. 257-263 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Scrophulariaceae ; Striga ; Buchnera ; Seed coat morphology ; systematics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Seeds of the root parasitesStriga (several spp.) andBuchnera americana were examined by means of SEM. The surface patterns of the seeds in both genera resemble each other closely, especially those ofS. angustifolia andB. americana. SomeStriga spp. can be clearly distinguished by their surface characteristics, while this is quite difficult in others. The taxonomic value of the seed surface features ofStriga andBuchnera is discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 192
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 171 (1990), S. 15-26 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Geraniaceae ; Pelargonium sect.Glaucophyllum ; Morphology ; pollen ; chromosome numbers ; flavonoids
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Pelargonium otaviense Knuth andP. spinosum Willd. are excluded from sect.Glaucophyllum, whileP. grandiflorum (Andr.)Willd.,P. patulum Jacq. andP. tabulare (Burm. f.)L'Hérit. of sect.Eumorpha are included. Sect.Glaucophyllum is characterized by green to glaucous vegetative organs and zygomorphic white to pink corolla with five narrow petals. All the species have an identical pollen and chromosome morphology, the same basic chromosome number (x = 11) and similar flavonoid patterns. A close relationship between sect.Glaucophyllum and sect.Pelargonium is indicated by the occurrence of natural hybrids and concordant characters. Isorhamnetin and luteolin have been detected in the genus for the first time.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 193
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 171 (1990), S. 99-115 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Malvaceae ; Gossypium ; Chloroplast DNA ; allozymes ; isozymes ; molecular evolution ; long-distance dispersal
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Molecular divergence betweenGossypium klotzschianum andG. davidsonii was studied. The former is endemic to five of the larger islands of the Galapagos, whileG. davidsonii is restricted to the southern half of Baja California, approximately 2 500 km distant. A substantial body of genetic and taxonomic data suggests that these two species are related as progenitor and derivative. Interspecific hybrids are fully fertile, with no evidence of F2 breakdown and normal segregation of genetic markers. Allozyme analysis of 33 populations for 41 loci indicated that the allelic composition ofG. klotzschianum represents a subset ofG. davidsonii. Although genetic diversity is relatively restricted in both species, calculated measures demonstrate higher levels of genetic variability and greater population structuring inG. davidsonii than inG. klotzschianum. The interspecific genetic identity of 0.87 is typical for progenitor-derivative species pairs. Chloroplast DNAs were surveyed for variation with 25 restriction enzymes using hybridization probes that cover the entire chloroplast genome. No intraspecific and little interspecific variation was detected among 560 cpDNA restriction sites, representing sequence information for approximately 3200 nucleotides. Only 3 mutational differences distinguished the two species, resulting in a sequence divergence estimate of 0.09%. Divergence times were estimated from both the isozyme data and the cpDNA restriction site data. Although these estimates have several sources of error, both molecular data sets were congruent in suggesting that the two lineages diverged between 250000 and 700000 years ago. Accumulated evidence suggests that dispersal was from Baja California to the Galapagos Islands rather than the reverse, and most likely was mediated by trans-oceanic drift.G. klotzschianum may be the only species of the endemic Galapagos flora to have arisen from a northern Mexican progenitor.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 194
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 171 (1990), S. 157-185 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Apocynaceae ; Plumerioideae ; Apocynoideae ; Holarrheninae ; Holarrhena ; Carruthersia ; Spirolobium ; Floral structure ; pollen morphology ; indole alkaloids ; steroidal alkaloids
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The genusHolarrhena, described byRobert Brown in 1811, has had a problematic taxonomic history, in part due to a suite of characters that does not conform with accepted concepts within theApocynaceae. In a number of important taxonomic charactersHolarrhena is typical of subfam.Apocynoideae. But due to the relatively unspecialized structure of the anthers most recent authors have placedHolarrheng, together withCarruthersia andSpirolobium, as the subtribeHolarrheninae in subfam.Plumerioideae. For the present investigation the floral structure and pollen morphology ofHolarrhena, Carruthersia andSpirolobium were analyzed. From the chemical literature reports of the occurrence of steroidal alkaloids in thePlumerioideae were evaluated. Our results indicate that the three genera belong to subfam.Apocynoideae in the tribeNerieae, but that the “Holarrheninae” is an unnatural group, and that the three genera should be accommodated individually within the tribe.
    Materialart: Digitale Medien
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  • 195
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Oleaceae ; Olea europaea ; Endoplasmic reticulum ; stacks cisternae ; pollen grain ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Characteristic features of rough endoplasmic reticulum (rER) distribution and proliferation were noted during olive pollen (Olea europaea L.) development, suggesting the physiological significance of this organelle. Initially scarce in the young microspore, ER increases as cytoplasmic vacuoles form. At the vacuolated microspore stage the cytoplasm contains numberous polysomes and elongated rER cisternae arranged preferentially in stacks, with an average intracisternal width of 0.07 µm. Stacks persist in the bicellular pollen grain but consist of fewer, shorter, dilated cisternae (mean intracisternal width 0.1 µm) containing a considerable electron-dense matrix. Cisternae in the mature grain are fragmented, leaving behind an ER of swollen pockets. Pockets of ER containing a material of greater electron density are evenly deposited along the plasmalemma, in close relation with it. A dense material is seen in the tubules of the apertural region, which was lacking in earlier stages. Our results show that ER may be involved in protein transport to the intine.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 196
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 172 (1990), S. 35-49 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Guttiferae ; Kielmeyera coriacea ; K. speciosa ; “Buzz pollination” ; carpenter bees ; breeding system ; andromonoecy ; self-mimicry ; neotropical savanna
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The pollination biology and breeding systems ofKielmeyera coriacea andK. speciosa, two sympatric woody species common in the cerrado vegetation of C. Brazil, were studied. Both species have similar nectarless, polystemonous “Papaver-type” flowers which are visited by a similar spectrum of insects, though they bloom in different seasons and are thus phenologically isolated. Large carpenter bees seem to be the most important pollinators and these and other bees effect “buzz pollen” retrieval despite the fact that anthers are not poricidal. Both species ofKielmeyera possess strong xenogamous breeding systems. The presence of staminate flowers and andromonoecy inK. coriacea, as well as the longevity ofK. speciosa flowers are discussed as alternative strategies to improve pollination success and reproductive efficacy.
    Materialart: Digitale Medien
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  • 197
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 172 (1990), S. 13-34 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Apocynaceae ; Tabernaemontana ; Indole alkaloids ; chemotaxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract According to their alkaloidal products species of the “new” genusTabernaemontana can be partly differentiated. This differentiation is in agreement with the “old” genera classification. From the chemotaxonomic point of view a subdivision of subfam.Plumerioideae of theApocynaceae is proposed.
    Materialart: Digitale Medien
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  • 198
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 172 (1990), S. 51-63 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Fumariaceae ; Papaveraceae ; Fumaria ; Phenetics ; numerical taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The taxonomy of the genusFumaria has not been considered in detail sincePugsley's work in 1919 ff., and few modern methods have been applied to it. In a phenetic study, 33 populations of 11Fumaria spp. were grown in uniform conditions, and seven morphological characters measured. After re-expression and transformation the data were analysed by cluster analysis and principal components analysis. Alternative analyses did not indicate contradictory taxonomic conclusions. Artificial crosses gave some evidence on interfertility, and suggestedF. occidentalis to be an allopolyploid ofF. bastardii ×F. capreolata. Pugsley's subsectional classification is supported within sect.Parviflora, but not within sect.Grandiflora. His two sections are seen to be meaningful, but not discrete.
    Materialart: Digitale Medien
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  • 199
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 172 (1990), S. 83-97 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Poaceae ; Pooideae ; Phylogenetics ; evolution ; chloroplast DNA ; restriction site variation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A phylogenetic analysis was conducted on chloroplast DNA restriction site variation in 34 genera of grasses (familyPoaceae), including 28 genera from subfam.Pooideae (representing tribesAveneae, Brachypodieae, Bromeae, Meliceae, Poeae, Stipeae, andTriticeae) and representatives of three other subfamilies,Arundinoideae, Oryzoideae, andPanicoideae. Analyses of all 34 genera always distinguishedPooideae as monophyletic, regardless of which nonpooid genus functioned as outgroup; six separate analyses of all 28 pooid genera, each including one of the six nonpooid genera as outgroup, resolved five identically-constituted clades withinPooideae (in four cases), or (in the other two cases) yielded results that were less well resolved, but not in conflict with those of the other four analyses. The four best-resolved analyses distinguishedMeliceae as the earliest diverging lineage withinPooideae, andStipeae as the next. Above the point of divergence ofStipeae is a dichotomy between supertribeTriticodae (including tribesBrachypodieae, Bromeae, andTriticeae), and a clade comprisingPoeae andAveneae. The analysis supports some tribal realignments, specifically the assignment ofBriza, Chascolytrum, Microbriza, andTorreyochloa toAveneae, andArctagrostis, Catabrosa, andSesleria toPoeae. The analysis also suggests that the pooid spikelet (i.e., glumes shorter than lemmas and florets two or more) is plesiomorphic inPooideae, and that spikelets with one floret, and those with glumes longer than the first lemma, each have evolved more than once withinPooideae. Results also indicate that small chromosomes and chromosome numbers based on x=c. 10−12 are plesiomorphic withinPooideae. Alternative states of these characters (chromosomes large, chromosome numbers based on x=7) are interpreted as synapomorphies or parallelisms of clades that includeTriticodae, Aveneae, andPoeae. Lanceolate lodicule shape may be a synapomorphy of the clade that includesStipeae, Triticodae, Aveneae, andPoeae, and loss of lodicule vascularization a synapomorphy of the entirePooideae.
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  • 200
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 172 (1990), S. 99-118 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Myrtaceae ; Eucalyptus ; Rarity ; allozymes ; phylogeny
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Phylogenetic relationships among the 12 species of the “green ash” group of eucalypts were examined using allozyme data, to investigate the causes of rarity in three localized endemics of the group. The relationships suggested by the allozyme data showed both similarities to and differences from those estimated from morphological data byLadiges and coworkers. The phylogenetic relationships suggest that rarity inEucalyptus burgessiana may be related to recent divergence, whileE. paliformis andE. rupicola are relatively old species, more likely to be relicts, and/or restricted to a rare habitat.
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