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  • 101
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 174 (1991), S. 17-35 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Solanaceae ; Nierembergia ; Tapinotaspis ; Centris ; Lanthanomelissa ; Paratetrapedia ; Pollination biology ; oil-flowers
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A morphological and anatomical description of the floral syndrome ofNierembergia is given, including a survey of the presence of elaiophores in most of its species, chromatography of the floral oils and observations on the pollinator behaviour. The principal pollinators areTapinotaspis spp. includingT. chalybaea which is endowed with oil collectors on the middle legs. Other exomalopsines (Lanthanomelissa andParatetrapedia) and centridines (Centris) also visitNierembergia for pollen and oil. Based on these observations and on a morphological study of the fertile parts, different pollination modes are recognized and the biogeography and evolution of the genus is discussed.
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  • 102
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Leguminosae ; Medicago truncatula f.laxicycla ; M. laxispira ; Evolution ; adaptation ; seed germination ; chromosome number ; Flora of Libya
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Medicago truncatula is a member ofMedicago sect.Spirocarpos, in which all 34 species have coiled fruit, usually tightly coiled, that permanently retain the seeds. A variant ofM. truncatula from Libya is unique for the species in possessing very loosely coiled fruits, and is here recognized as a new forma,M. truncatula f.laxicycla E. Small. In germination tests of a number of species ofMedicago, the unusual Libyan variant proved to be the only one in which rapid and simultaneous germination of most of the seeds occurred while still within a fruit. The loose coiling of the fruit of the Libyan variety appears to facilitate water entry and seedling escape. Its rapid germination might adapt it to respond quickly to intermittently available moisture, but at the cost of abandoning the strategy of intermittent germination adopted by other populations ofMedicago sect.Spirocarpos.
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  • 103
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 174 (1991), S. 47-66 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Poaceae ; Hordeum patagonicum complex ; barley ; Classification ; numerical methods ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Seeds of theHordeum patagonicum complex were collected from the field and grown in the greenhouse. The aim was to take a sample of members of the complex, and on the basis of the phenotypic similarities in some morphological and physiological characters, determine whether distinct groups exist. When cluster analyses, to generate hypotheses, and orthodox statistical procedures, for hypotheses obtained a priori, were applied to the reproductive morphology, germination and flowering patterns, onlyH. patagonicum subsp.magellanicum, out of the five recognized taxa, could be distinguished consistently. The remaining four taxa, which overlapped considerably, could be re-formed into three groups whose centroids were different but whose ranges of variation were not distinct from each other. We conclude that the highly cross-compatible members of theH. patagonicum complex, first defined as species and later redefined as subspecies are probably no more than biotypes.
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  • 104
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 174 (1991), S. 75-82 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Poaceae ; Triticeae ; Elymus ; Hordeum ; Intergeneric hybrids ; genome analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The results of genome analysis of five hybrids, viz.Elymus patagonicus ×Hordeum procerum, E. patagonicus ×H. tetraploidum, E. angulatus ×H. jubatum, E. angulatus ×H. lechleri, andE. angulatus ×H. parodii, are reported. The genomic constitution ofHordeum tetraploidum andH. jubatum is best given as H1H1H2H2, ofH. lechleri andH. parodii as H1H1H2H2H4H4, ofH. procerum as H1H1H2H2H3H3, and ofElymus patagonicus andE. angulatus as SSH1H1H2H2.
    Materialart: Digitale Medien
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  • 105
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 174 (1991), S. 67-73 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Campanulaceae ; Campanula isophylla ; C. elatines ; C. elatinoides ; C. fragilis subsp.fragilis and subsp.cavolinii ; C. garganica ; C. fenestrellata subsp.istriaca ; C. portenschlagiana ; Allozyme variation ; heterozygosity ; Flora of Italy and W. Jugoslavia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Variability and genetic divergence of 11 field populations of seven species of theCampanula elatines andC. fragilis rock-plants group from the Mediterranean and pre-Alpine areas have been studied by starch-gel electrophoretic techniques.Campanula isophylla, C. elatines, C. elatinoides, C. fragilis subsp.fragilis and subs.cavolinii, C. garganica were collected in Italy, whilstC. fenestrellata subsp.istriaca andC. portenschlagiana came from W. Jugoslavia. Twelve enzymatic loci for each population were genetically analysed: PGI-1 and 2, PGM-2, IDH-1 and -2, SKDH, ME, ADH, GOT-2, MPI-1 and -2, SOD-1. The genetic distances among the above mentioned entities have been calculated by Nei's index and depicted in a dendrogram.
    Materialart: Digitale Medien
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  • 106
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 174 (1991), S. 83-91 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Labiatae ; Teucrium sect.Chamaedrys ; Taxonomy ; trichomes ; Flora of Italy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Micromorphology and distribution of trichomes (both secretory and not) in different parts of plants of the five Italian species belonging toTeucrium sect.Chamaedrys have been studied. These characters neatly evidence the differences between the taxa considered; of particular interest are the observations concerning the dense coverage of peltate hairs on the abaxial face of the leaves ofT. flavum subsp.glaucum and the characters contributing to a better identification ofT. marum andT. subspinosum. The importance of the calyx indumentum as distinctive taxonomical character of the genusTeucrium is confirmed, stressing at the same time the necessity of completing the observations at micromorphological level.
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  • 107
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 174 (1991), S. 93-101 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Orchidaceae ; Myrosmodes cochleare ; Pollination ; breeding system ; Andes of Venezuela
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Myrosmodes cochleare is a terrestrial orchid restricted to high elevations of the northern Andes. It is self-compatible but not autogamous. Flowering begins at the apex of the inflorescence, but flower size increases steadily towards the base. Fruit set of selfed flowers was found to increase significantly from the apex to the base of the inflorescence. Open-pollinated fruit set was significantly lower than hand-pollinated fruit set overall, but the highest levels occurred in the middle of the inflorescence. Eumenid wasps and a calliphorid fly were observed to pollinate the flowers, but visits were rare and occurred only during infrequent warm periods.
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  • 108
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 174 (1991), S. 103-108 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Poaceae ; Triticeae ; Kengyilia habahenensis ; spec. nova ; Taxonomy ; genome analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Kengyilia habahenensis, spec. nova, from the Altai mountains, China, is described morphologically and cytologically. It has 2n = 42 chromosomes, and the genome formula PYS.
    Materialart: Digitale Medien
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  • 109
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 174 (1991), S. 109-114 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Rhamnaceae ; Condalia ; Lipid analysis ; seed protein electrophoresis ; chemical variation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Seed oil composition (sterol esters and sterols) and seed protein profiles ofCondalia microphylla were investigated. The chemical differences observed may be attributed to genotypic changes and could support the existence of infraspecific taxa.
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  • 110
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 174 (1991), S. 115-123 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Orchidaceae ; Anacamptis pyramidalis ; A. urvilleana ; Polyploidy ; isolation mechanisms ; speciation ; Flora of the Mediterranean ; Malta
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Anacamptis pyramidalis is a variable and wide-spread European-Mediterranean taxon. Beside a dominant cytotype with 2n = 36 it includes cytotypes with 2n = 54 and 63 in northern Tuscany (and the Eastern Pyrenees) and one with 2n = 72 on Malta. In contrast,A. urvilleana, formerly often misidentified and included inA. pyramidalis, is a monomorphic and distinct species, endemic to the Maltese Islands. It has 2n = 36, can be clearly separated by morphological and anatomical features and is isolated from partly sympatric populations ofA. pyramidalis with 2n = 72 by differences in chromosome number, flowering time and habitat preference.
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  • 111
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 174 (1991), S. 125-137 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Liliaceae ; Allium schœnoprasum ; C-banding ; karyotype polymorphism ; geographical variation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Variation in C-banding was studied in seven populations ofAllium schœnoprasum from eastern N. America, including populations referable to var.sibiricum, var.laurentianum, and ± intermediate. 23 bands were recognized on five pairs of chromosomes, and were treated as 23 loci. No banding site was monomorphic throughout the plants studied. The level of polymorphism per population was 〉60%, and the average heterozygosity values varied from 0.21 to 0.27. The various “banding patterns” of chromosomes were shown to depend on the random combination of individual bands. Nei's genetic distances between populations varied from 0 to 0.070 (mean: 0.033). The matrix of genetic distances was analysed by non-metric multidimensional scaling, and the results showed a significant relationship between longitude and population scores on the ordination. The chromosomal data did not clearly discriminate between the two native varieties ofA. schœnoprasum, but were interpreted as a longitudinal cline. It is suggested that studies of C-banding variation in vascular plants should focus on individual banding sites, rather than on whole chromosome banding patterns.
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  • 112
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 174 (1991), S. 139-158 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Gentianaceae ; Gentianella germanica ; Gentianella campestris ; Seasonal dimorphism ; seasonal differentiation ; seasonal ecotypes ; flowering time ; aestival and autumnal vicariads ; grazing
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Plant samples were collected from 13 populations of the two speciesGentianella germanica andG. campestris. In addition, two samples from populations of grazed plants lacking their main stems were collected. A number of relevant morphological characters were measured, the flowering time, and the habitats of each population were studied. Some ecotypes ofG. germanica with clear differences in flowering time were recognized. Differences in flowering time and morphology between populations ofG. campestris seem to be clinal. The generally accepted theory of seasonal dimorphism with the assumption of separate aestival and autumnal vicariads proves to be inadequate. A hypothesis based upon the effect of human influences on the origin of this ecotypes is suggested.
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  • 113
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 174 (1991), S. 159-169 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Fabaceae ; Arachis batizocoi ; A. hypogaea ; Genome analysis ; phylogenetic relationships
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Arachis batizocoi Krap. & Greg. is a suggested B genome donor to the cultivated peanut,A. hypogaea L. Until recently, only one accession of this species was available in U.S.A. germplasm collections for analyses and species variability had not been documented. The objective of this study was to determine the intraspecific variability ofA. batizocoi to better understand phylogenetic relationships in sect.Arachis. Five accessions of the species were used for morphological and cytological studies and then F1 intraspecific hybrids analyzed. Some variation was observed among accessions—for example, differences in seed size, plant height and branch length. The somatic chromosomes of accessions 9484, 30079, and 30082 were nearly identical, whereas, the karyotypes of accessions 30081 and 30097 have several distinct differences. For example, 30081 had significantly more asymmetrical chromosomes 2 and 6 and more median chromosomes 7 and 10, and 30097 had significantly more asymmetrical chromosomes 3 and 10 and more median chromosomes 1 and 5 than accessions 9484, 30079, and 30082. All F1 hybrids among accessions were highly fertile. Meiotic observations indicated that hybrids among accessions 9484, 30079, or 30082 had mostly bivalents. However, quadrivalents were observed when either 30081 or 30097 was crossed with the above three accessions and 30081 × 30097 had quadrivalents, hexavalents and octavalents. The presence of translocations is the most likely cause of multivalent formation inA. batizocoi hybrids. Cytological evolution via translocations has apparently been an important mechanism for differentiation in the species.
    Materialart: Digitale Medien
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  • 114
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 174 (1991), S. 183-195 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Polygonaceae ; Rumex acetosa ; R. acetosella ; Sex ratios ; spatial segregation of the sexes ; environmental correlations ; density effects
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Populations ofRumex acetosa andR. acetosella were studied during two growth seasons. The ramet sex ratios ofR. acetosa were always female-biased. InR. acetosella the sex ratios expressed more variation but were mostly female-biased. In both species the sex ratios commonly varied between subpopulations reflecting a partial spatial segregation of the sexes. No marked differences between sexes in vegetative vigour were detected in either species. Interactions between sex ratios, various soil characteristics and population densities were determined. Possible mechanisms for causing biased sex ratios and partial spatial segregation of the sexes are discussed.
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  • 115
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 174 (1991), S. 197-211 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Rubiaceae ; Rubieae ; Asperula sect.Oppositifoliae ; sect. nova ; spec. novae:A. rezaiyensis ; A. rechingeri ; Galium spec. novae:G. anguineum ; G. azerbayjanicum ; G. plurifolium ; G. pseudomegalanthum ; G. kandavanense ; G. wendelboi ; G. sojakii ; G. subvelutinum var.oligotrichum ; var. nova ; G. decumbens ; G. problematicum ; stat. nov ; Flora of Iran
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Asperula sect.Oppositifoliae is validated. 2 new species ofAsperula and 7 new species and 1 variety ofGalium from Iran are described, discussed in respect to their affinities and illustrated. 2 subspecies are raised to species rank.
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  • 116
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 175 (1991), S. 1-10 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Iridaceae ; Tigridieae ; Leaf anatomy ; systematics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Leaf anatomy is described in 32 species of 16 genera of the New World tribeTigridieae (Iridaceae, Iridoideae), including examples from both subtribesCipurinae andTigridiinae. Both plicate (pleated) and foliated (with flanges, or keel extensions) leaf types occur in both subtribes. However, amongTigridiinae, foliated leaves are restricted toTigridia and differ from the foliated leaves ofCipurinae in that they lack subepidermal marginal sclerenchyma, which is present in all the foliated species ofCipurinae. This indicates that the foliated leaf type has evolved at least twice in the tribe, since the plicate leaf, which most closely resembles the equitant leaf typical ofIridaceae, is probably plesiomorphic.
    Materialart: Digitale Medien
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  • 117
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 174 (1991), S. 213-220 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Orchidaceae ; Platanthera bifolia ; Embryology ; embryo sac ; megasporogenesis ; megagametogenesis ; confocal scanning laser microscopy (CSLM)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Flowers ofPlatanthera bifolia were hand-pollinated and fixed in FPA50 after 2, 5, 7, 14, and 21 days. Ovules, made transparent in Herr's clearing fluid, were investigated using confocal scanning laser microscopy. Pollination initiates the megasporogenesis. Two days after pollination dyads are frequent. Three days later most embryo sacs contain two nuclei. Seven days after pollination the embryo sacs are 4–8-nucleate and some are organized, and a week later all embryo sacs are organized and fertilization takes place. The embryo sac development follows thePolygonum type. Twenty-one days after pollination the egg nuclei have been fertilized and the embryo sacs contain 2- to many-celled embryos. A suspensor is formed during early stages of embryo development but degenerates later. Fertilization of the central nucleus does not lead to endosperm development.
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  • 118
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 175 (1991), S. 11-21 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Leguminosae ; Cicer ; Allozymes ; isozyme gene duplication ; phylogenetic relations ; polymorphism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Allozymic variation at 30 isozyme loci was examined electrophoretically in nine annual and one perennial species ofCicer. While most of the accessions examined were monomorphic, species can be differentiated on the basis of their enzyme phenotypes. Several groups of species were identified based upon genetic distance values. For example,C. arietinum, C. reticulatum, andC. echinospermum shared the same alleles for most of the loci exmained. PerennialC. anatolicum is also closely related to this group. Similarly,C. judaicum, C. bijugum, andC. pinnatifidum formed another group. Two annual species,C. chorassanicum andC. yamashitae clustered together, whereasC. cuneatum was the most distantly related species. Correlations were found between genetic distances and geographic distribution. Results from enzyme electrophoresis tend to support the previously reported taxonomic treatments based upon crossability and morphological similarity. However,C. yamashitae, which has been classified in the second crossability group, is quite distinct genetically and morphologically from the remaining species of the group. An isozyme gene duplication observed in the genus suggested the monophyletic origin of the species examined in the present study.
    Materialart: Digitale Medien
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  • 119
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 175 (1991), S. 39-54 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Rubiaceae ; Chloroplast DNA ; fragment analysis ; restriction analysis ; site analysis ; Wagner parsimony
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Information from the same restriction analysis of chloroplast DNA of 33 taxa ofRubiaceae was scored in four different ways, two of which were based on fragments, and two on restriction sites, and they were subsequently analysed with Wagner parsimony. The methods resulted in different phylogenetic trees. The inherent differences between the methods relate to the amount of non-homologous characters and dependent characters, but none of the methods will systematically bias the resulting cladograms. The fragment analyses are much less time-consuming, but probably less accurate, than the site analyses. The choice of method is dependent on a trade-off between accuracy and resources (time). One important recommendation is made: all phylogenetic analyses of chloroplast DNA data should be accompanied by a data matrix and contain information on how the matrix was compiled.
    Materialart: Digitale Medien
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  • 120
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 175 (1991), S. 55-72 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Orchidaceae ; Dactylorhiza ; D. maculata ; D. fuchsii ; D. saccifera ; D. caramulensis ; Biostatistics ; multivariate analysis ; taxonomy ; morphology ; Flora of Western-Europe
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Multivariate analysis tools are exploited on a data set composed of quantitative characteristics collected on 35 populations of plants of theDactylorhiza maculata (L.)Soó group from Western-Europe. These samples lead to four well-defined clusters; this, together with qualitative, cytological and ecological arguments, allows for the recognition of four specific entities:D. maculata s.str.,D. fuchsii (Druce)Soó,D. saccifera (Brongn.)Soó andD. caramulensis (Vermeulen)Tyteca. It is concluded that the floral characters play an essential role in the taxonomical distinction. It also appears that the set of characters measured, as well as the methods exploited, are especially well-suited and valuable tools for the morphological study of the genusDactylorhiza.
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  • 121
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 175 (1991), S. 73-86 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Hyacinthaceae ; Ornithogalum subg.Heliocharmos ; O. angustifolium ; O. divergens ; O. monticolum ; O. tenuifolium ; O. umbellatum ; Numerical taxonomy ; systematics ; evolution ; Flora of France
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Macromorphological variation within theOrnithogalum umbellatum L. (Hyacinthaceae) complex in France was studied. The resulting data were treated by numerical taxonomy methods. Three morphs can be identified: one corresponding to diploid plants, another made up of triploids and a third which encompasses plants having ploidy level above 3x (4x, 5x, and 6x). A systematic interpretation of the complex is proposed wherein only one species,O. umbellatum, is retained. This species corresponds to a polyploid complex undergoing evolution.
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  • 122
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 175 (1991), S. 87-92 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Compositae ; Eupatorieae ; Mikania ; Mikania swartziana complex ; Dioecy ; Flora of the Greater Antilles
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract For the first time dioecy inMikania and in the tribeEupatorieae is described and discussed. The condition is known only in members of theMikania swartziana Griseb. complex, a group of eight species, all endemic to the Greater Antillean Islands of Cuba, Hispaniola, and Jamaica.
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  • 123
    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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  • 124
    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.
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  • 125
    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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  • 126
    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.
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  • 127
    Digitale Medien
    Digitale Medien
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    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.
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  • 128
    Digitale Medien
    Digitale Medien
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    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.
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  • 129
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    Digitale Medien
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    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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  • 130
    Digitale Medien
    Digitale Medien
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    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.
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  • 131
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    Digitale Medien
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    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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  • 132
    Digitale Medien
    Digitale Medien
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    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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  • 133
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    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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  • 134
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    Digitale Medien
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    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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  • 135
    Digitale Medien
    Digitale Medien
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    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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  • 136
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    Digitale Medien
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    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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  • 137
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    Digitale Medien
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    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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  • 138
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    Digitale Medien
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    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.
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  • 139
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    Digitale Medien
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    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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  • 140
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    Digitale Medien
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    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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  • 141
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    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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  • 142
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    Digitale Medien
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    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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  • 143
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    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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  • 144
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    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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  • 145
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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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  • 146
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    Digitale Medien
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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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  • 147
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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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  • 148
    Digitale Medien
    Digitale Medien
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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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  • 149
    Digitale Medien
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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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  • 150
    Digitale Medien
    Digitale Medien
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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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  • 151
    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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  • 152
    Digitale Medien
    Digitale Medien
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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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  • 153
    Digitale Medien
    Digitale Medien
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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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  • 154
    Digitale Medien
    Digitale Medien
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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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  • 155
    Digitale Medien
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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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  • 156
    Digitale Medien
    Digitale Medien
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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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  • 157
    Digitale Medien
    Digitale Medien
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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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  • 158
    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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  • 159
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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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  • 160
    Digitale Medien
    Digitale Medien
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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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  • 161
    Digitale Medien
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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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  • 162
    Digitale Medien
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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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  • 163
    Digitale Medien
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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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  • 164
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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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  • 165
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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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  • 166
    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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  • 167
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    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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  • 168
    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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  • 169
    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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  • 170
    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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  • 171
    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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  • 172
    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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  • 173
    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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  • 174
    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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  • 175
    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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  • 176
    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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  • 177
    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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  • 178
    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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  • 179
    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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  • 180
    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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  • 181
    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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  • 182
    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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  • 183
    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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  • 184
    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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  • 185
    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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  • 186
    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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  • 187
    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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  • 188
    Digitale Medien
    Digitale Medien
    Springer
    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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  • 189
    Digitale Medien
    Digitale Medien
    Springer
    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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  • 190
    Digitale Medien
    Digitale Medien
    Springer
    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.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 191
    Digitale Medien
    Digitale Medien
    Springer
    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.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 192
    Digitale Medien
    Digitale Medien
    Springer
    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.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 193
    Digitale Medien
    Digitale Medien
    Springer
    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.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 194
    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.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 195
    Digitale Medien
    Digitale Medien
    Springer
    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.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 196
    Digitale Medien
    Digitale Medien
    Springer
    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.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 197
    Digitale Medien
    Digitale Medien
    Springer
    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.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 198
    Digitale Medien
    Digitale Medien
    Springer
    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.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 199
    Digitale Medien
    Digitale Medien
    Springer
    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.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 200
    Digitale Medien
    Digitale Medien
    Springer
    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.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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