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  • Angiosperms  (680)
  • Springer  (680)
  • 1
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    Plant systematics and evolution 222 (2000), S. 1-17 
    ISSN: 1615-6110
    Keywords: Angiosperms ; pollen ; pollen wall ; pollination ; exine ; intine ; aperture ; ornamentation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Qualities of the stratified pollen walls were evaluated for their possible role in pollination (pollination modes, and pollen tube formation). The importance of studying pollen grains in their respective natural state is noted. Examples of pollen morphological features specific to pollination vectors are rare and difficult to demonstrate. However, some complex, but significant correlations are reported.
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  • 2
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    Plant systematics and evolution 222 (2000), S. 281-292 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Echium ; Esterhazya ; pollination ecology ; anthers ; pollen ; secondary pollen presentation ; sporopollenin ; viscin threads
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This paper reviews the origin, nature, systematic distribution, and the respective function of the highly variable and diverse thread-forming structures in angiosperm anthers (including somewhat similar, rare features in ferns and gymnosperms). On one hand, such threads may function as pollen-connecting vectors in forming pollen dispersal units, as sporopollenin threads (viscin threads), e.g. in Onagraceae, or sporopollenin-less threads in surprisingly many other angiosperm families. On the other hand, as is known from theImpatiens — “pollen basket”, threads or ropes may be involved in pollen presentation. In addition, for the first time two new examples of “pollen baskets” in Boraginaceae and Scrophulariaceae are reported. InEchium the basket is formed by cellular elements from the modified septal regions, whereas inEsterhazya a similar effect is achieved in an analogous manner by trichomes of the epidermal layer of the thecal wall. There is obviously a different function of these seemingly very similar baskets: inEchium the feature acts preferably as a pollen presentation agent, whereas inEsterhazya the primary function is to prevent all the pollen from being dispersed too soon.
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  • 3
    ISSN: 1615-6110
    Keywords: Angiosperms ; Campanulaceae ; Wahlenbergia ; Breeding system ; pollination ; pollen collecting hairs ; autogamy ; self-compatibility ; nectar ; island biology ; Juan Fernández Islands
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The reproductive biology ofW. berteroi, W. fernandeziana, and a putative hybrid betweenW. fernandeziana andW. grahamiae, endemic to Robinson Crusoe Island (Juan Fernández archipelago, Chile) was studied. Flowers are hermaphroditic, protandrous, offer nectar, and exhibit secondary pollen presentation involving pollen collecting hairs on the style. These features imply allogamy and biotic pollination. However, male and female phases overlap and no effective pollinators were observed. Experimental data indicate these taxa are self-compatible and facultatively autogamous, a conclusion also suggested by the pollen/ovule ratios. Selfing is accomplished when the stigmatic lobes reflex and touch the style, except forW. berteroi where they do not reflex completely. Autogamy is accomplished in the latter when pollen grains deposited on the inner surface of the corolla throat by the “pollen brush” are gathered by stigmatic lobes when shaken by wind. The degree of autogamy, and perhaps self-compatibility, seems to be inconstant, as implied by the variable natural seed set (overall range 21–188 seeds per fruit). A mixed mating system — primarily outcrossing/entomophilous, but also autogamous — must have been present in the continental ancestors of these taxa. Autogamy promoting self-fertilization is important now — on an island with scarce pollinators — and in the past — when the first founders arrived.
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  • 4
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    Plant systematics and evolution 217 (1999), S. 43-53 
    ISSN: 1615-6110
    Keywords: Leguminosae ; Caesalpinia ; Angiosperms ; bee-pollination ; andromonoecy ; late-acting self-incompatibility ; fruiting success
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The pollination biology, breeding system and fruiting success ofCaesalpinia calycina andC. pluviosa var.sanfranciscana were studied in caatinga vegetation in Bahia, NE Brazil. The principal pollinators for both species were carpenter bees.Caesalpinia calycina is andromonoecious but inC. pluviosa all flowers are hermaphrodite. InC. calycina all selfed flowers were abscised within 72 h despite rapid self-pollen tube growth to the ovary and ovule penetration. Prevention of selfing therefore seems to be controlled by a post-zygotic mechanism. Both species had very low fruit-set and it is suggested that this is at least in part due to geitonogamous pollinations with ovule penetration by self pollen tubes.
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  • 5
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    Plant systematics and evolution 214 (1999), S. 161-186 
    ISSN: 1615-6110
    Keywords: Rubiaceae ; Rubioideae ; Angiosperms ; cladistics ; DNA sequences ; phylogeny ; rps16 intron ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The phylogeny of the subfamilyRubioideae (Rubiaceae) was estimated from sequence variation in therps16 intron (cpDNA) in 143 ingroup and 5 outgroup taxa. The analysis largely confirms a recent one based onrbcL sequences, but branch support is often much stronger. Three of the traditional subfamilies are supported,Rubioideae, Cinchonoideae s. str., andIxoroideae s. l. while there is no support forAntirheoideae. TheRubioideae are the sister group of all otherRubiaceae and comprise the tribesAnthospermeae, Coccocypseleae, Cruckshanksieae, Coussareeae, Gaertnereae, Hedyotideae, Knoxieae, Morindeae, Ophiorrhizeae, Paederieae, Pauridiantheae, Perameae, Psychotrieae, Rubieae, Spermacoceae, Theligoneae, andUrophylleae. TheHamelieae andHillieae belong to theCinchonoideae. Rachicallis andSiemensia should be transferred from theHedyotideae to theCinchonoideae. ThePauridiantheae, Urophylleae, Ophiorrhizeae, andRaritebe form the basalmost subclade of theRubioideae. The second basalmost clade consists of the generaLasianthus andPerama. The third basalmost clade consists of the tribesCoussareeae, Coccocypseleae andCruckshanksieae, and the generaDeclieuxia andHindsia. The tribesKnoxieae, Anthospermeae, Argostemmateae, Paederieae, Theligoneae, Rubieae, Hedyotideae, andSpermacoceae are members of one clade. TheKnoxieae are monophyletic ifOtiophora, Otomeria, andPentas are included. The tribeAnthospermeae is supported as monophyletic, but its subtribes are not. ThePaederieae, together withTheligonum, form a paraphyletic grade basal to theRubieae. TheHedyotideae, includingSchismatoclada, form a grade at the base of theSpermacoceae. TheGaertnereae are monophyletic and distinct from thePsychotrieae. TheMorindeae are monophyletic and includeDamnacanthus andMitchella. Schradera is the sister group of theMorindeae. ThePsychotrieae are monophyletic when theGaertnereae, Lasianthus, andDeclieuxia are excluded. The recognition of a subtribeHydnophytineae leaves the rest of thePsychotrieae paraphyletic.Psychotria is paraphyletic with respect to all other genera of the tribe. Approximately 50 genera are here classified for the first time based on molecular data.
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  • 6
    ISSN: 1615-6110
    Keywords: Campanulaceae ; Lobelia ; Angiosperms ; in situ hybridization ; karyotype evolution ; rDNA ; telomere
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Three repeated DNA sequences (rDNA 5S, 18S-5.8S-26S and telomeric repeats) were localised in the genomes ofLobelia brasiliensis andL. imperialis var.kanitzii (subg.Tupa), both with 2n = 28, by fluorescence in situ hybridization (FISH). The results were used to analyse the genomic relationship between the species. With probe pTa71, the karyotypes of these species showed only one NOR site. Probe pTa794, which contains 5S rDNA, demonstrated differences between the species. Telomeric sequences, studied with probe pLT11, were not detected in ectopic sites, but different telomeres showed signals of varying intensity. Based on the results obtained, considerations are made on karyotype evolution inLobelia.
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  • 7
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    Plant systematics and evolution 216 (1999), S. 265-288 
    ISSN: 1615-6110
    Keywords: Illiciaceae ; Illiciospermum ; Liriodendroidea ; Magnoliaceae ; Angiosperms ; Cretaceous ; fossil seeds ; Kazakhstan
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cenomanian-Turonian sediments from the Sarbay locality in north-western Kazakhstan have yielded a rich assemblage of plant fossils including well preserved flowers, fruits, and seeds of angiosperms. This work describes fossil seeds assigned to theMagnoliaceae and theIlliciaceae. Three new species of the extinct magnoliaceous genusLiriodendroidea, L. asiatica, L. costata, andL. tenuitesta, are established and new information on the previously described species,L. alata, is provided. TheLiriodendroidea seeds are closely similar to seeds of extantLiriodendron, but are distinguished in being much smaller and winged. A new genus and species,Illiciospermum pusillum, is established based on seeds with close similarity to those of the extant genusIllicium. The seeds are small, anatropous and exotestal with outer epidermis of testa forming a palisade layer. The facets of the palisade cells have deeply undulate anticlinal walls. The micropyle area is seen on the outer integument as a transverse slit placed on a raised strophiole-like structure close to the hilum. TheIlliciospermum seeds represent the first unequivocal record of theIlliciaceae in the Cretaceous. Another seed of possible illiciaceous affinity is described as aff.Illiciospermum sp.
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  • 8
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    Plant cell reports 18 (1998), S. 143-147 
    ISSN: 1432-203X
    Keywords: Key wordsNicotiana tabacum ; Male germ unit ; Scanning electron microscopy ; Sperm isolation ; Angiosperms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Sperm cells are released from pollen tubes of tobacco as linked cells, associated with the vegetative nucleus in an assemblage known as the male germ unit (MGU). Using light microscopy, the MGU assemblage appears to be ensheathed by cytoplasmic material of the pollen tube, which may stabilize their association. Following their release, the shape of the sperm cells and vegetative nucleus changes from an ellipsoidal to a more spheroidal morphology. When most of the cytoplasmic material is dispersed, a boundary remains around the two sperm cells. Using scanning electron microscopy, the cytoplasmic material surrounding the MGU appears filamentous, sometimes twisted and rope-like. Based on these observations, the function of the MGU of tobacco is discussed.
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  • 9
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    Plant systematics and evolution 207 (1997), S. 13-42 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Magnoliidae ; Chloranthaceae ; Chloranthistemon ; Palaeobotany ; Cretaceous fossils ; floral evolution ; flower morphology ; pollen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract New chloranthaceous floral structures from the Late Cretaceous (Late Santonian/Early Campanian) of Scania, southern Sweden, have provided important new information on theChloranthistemon plants. The material includes well preserved fragments of inflorescence axes with flowers in situ documenting thatChloranthistemon flowers were bisexual and closely resembled those of extantChloranthus (Chloranthaceae). An emended diagnosis is given for the type species of the genus,Chloranthistemon endressii, and a new species,C. alatus, is described. The flowers ofChloranthistemon are small, perianthless and strongly zygomorphic, consisting of a tripartite and broadened androecium borne in an abaxial to lateral position on the monocarpellate ovary, and arranged in the axils of decussate bracts. Stamens are either completely free (C. alatus), or free at the base and coherent at the apex (C. endressii). The apical connective is extensive in both species; elaborated into conspicuous wing-like structures inC. alatus, or into a massive and shield-like structure inC. endressii. Pollen grains ofC. endressii are spheroidal, and reticulate and spiraperturate, while those ofC. alatus are ellipsoidal, tectate and foveolate with a unique combination of a distal colpus and a proximal furrow (colpus?) perpendicular to each other. Ovaries observed in well preserved flowers of both species are small and undifferentiated. Larger, dispersed fruits of chloranthaceous affinity are abundant and distinct, and probably represent at least two or three species, but cannot be linked with certainty to any of theChloranthistemon species described here.
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  • 10
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    Journal of molecular evolution 43 (1996), S. 399-404 
    ISSN: 1432-1432
    Keywords: Asarum ; Dioscorea ; Angiosperms ; Evolution ; Legumins ; Seed proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Analysis of legumin-encoding cDNAs fromDioscorea caucasica Lipsky (Dioscoreaceae) and fromAsarum europaeum L. (Aristolochiaceae) shows that there is an especially methionine-rich legumin subfamily present in the lower angiosperm clades including the Monocotyledoneae. It is characterized by a methionine content of 3–4 mol% which is roughly triple the methionine proportion of most other legumins. These “MetR” legumins, if present, still have to be detected in the higher angiosperms including the important seed crops. Evolutionary analysis suggests that the MetR legumins are the result of a gene duplication allowing the differentiation of legumin genes according to their sulfur content. The duplication event must have taken place before the split into mono- and dicotyledonous plants but probably after the separation of angiosperms and gymnosperms.
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  • 11
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    Plant systematics and evolution 199 (1996), S. 121-152 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Leaf development ; organismal approach ; blastozone ; organogenetic competence ; primary morphogenesis ; marginal meristems ; topography ; eumeristem ; cytohistological gradients
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A new term — the “blastozone” — is proposed to designate regions of the shoot competent for organogenesis. It is argued that the notion of “marginal meristems” is based on the cell theory and thus may not be appropriate to elucidate the process of organ formation. For instance, with respect to the occurrence of initials and of an elevated cell division rate marginal meristems have been shown to be doubtful structures. Furthermore, organogenetic competent regions form only parts of the meristems of the shoot. The study of blastozones from an organismic perspective reveals primary morphogenetic events such as initiation, incorporation, and fusion processes. Loss of morphogenetic competence is associated with histogenetic events, e.g., trichome outgrowth, and indicates the onset of processes leading to maturation. The marginal blastozone of the leaf is then used up although meristem features continue to be expressed. A series of SEM studies in several genera exemplifies the proposed viewpoint, demonstrating some of the morphogenetic potentialities of angiosperm leaf marginal blastozones.
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  • 12
    ISSN: 1615-6102
    Keywords: Fertilization ; Pollen tube ; Embryo sac ; Gametes ; Angiosperms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Since its discovery at the end of the last century, double fertilization remains of central interest in plant reproductive biology research. Although the sequence of events leading to fertilization is well known from cytological studies, the underlying mechanisms remain to be elucidated. This now seems feasible by the diversification and refinement of recently developed technologies presented in this review. The progress made during the last five years in understanding pollen tube guidance, discharge into the embryo sac, and gametic fusion are described. Future directions are also discussed.
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  • 13
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    Plant systematics and evolution 202 (1996), S. 211-218 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Cunoniaceae ; rbcL sequence ; cladistic analysis ; identification ; New Zealand ; Gondwana
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We report the first example of identification of an unknown flowering plant to family level using comparison of DNA sequences. The newly-discovered New Zealand plant had not been identified by traditional methods, but has been placed in the Gondwanic familyCunoniaceae on the basis of the sequence of its chloroplastrbcL gene. It has not flowered, but its vegetative characters are typical of the family. However, it is clearly unusual in several morphological and anatomical features and appears to match no known genus. We consider that, although it probably represents an unnamed new genus, it could possibly be a mutant dwarf form ofWeinmannia racemosa, so it is not prudent to name it at this time.
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  • 14
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    Plant systematics and evolution 200 (1996), S. 125-140 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Colour change ; floral colour phase ; innate flower detection ; colour preference ; pollination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Many angiosperms have arranged their flowers in inflorescences forming a distinct signalling unit to flower visitors. In some species, the flowers of inflorescences undergo a temporal colour change corresponding exactly to a change in the reward status. Based on information obtained from the spectral reflection curves of pre-change and postchage colours of flower corollas and/or floral guides, it was possible to demonstrate that the colour phase associated with reward closely corresponds to the visual stimuli which trigger behavioural responses of inexperienced flower visitors, and that the colour phase associated with less reward corresponds to visual stimuli less attractive to naïve flower visitors. Reciprocal colour changes were not observed. It is to be assumed that the unidirectionality of floral colour changes is an adaptation of angiosperms aimed at the guidance of first-time flower visitors. Signalling reward to inexperienced flower visitors is an additional function of floral colour changes. The main function of floral colour changes, however, is to provide cues with which the flower visitors can learn to associate one colour phase with reward.
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  • 15
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    Plant systematics and evolution 196 (1995), S. 227-241 
    ISSN: 1615-6110
    Keywords: Angiosperms ; gymnosperms ; bryophytes ; Telomeres ; fluorescent in situ hybridization ; karyotype evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Data for chromosomal localization of theArabidopsis-type of telomeric sequence repeats (TTTAGGG)n are compiled for 44 species belonging to 14 families of angiosperms, gymnosperms and bryophytes. For 23 species and seven families this is the first report. Species of all families, except theAlliaceae, revealed these sequences at their chromosome termini. This indicates thatArabidopsis-type telomeric repeats are highly conserved. It is inferred that they represent the basic telomere sequence of higher plant phyla. In theAlliaceae, a deviating sequence (and mechanism?) for the stabilization of chromosome termini has possibly evolved secondarily. Nine species revealed interstitial telomeric sequences in addition to the terminal ones, in three species (Vicia faba, Pinus elliottii, P. sylvestris) also at centromeric positions. Interstitial telomeric sequences may indicate karyotype reconstructions, in particular alterations of chromosome numbers by chromosome fusion — or inversions with one breakpoint within the terminal array of repeats. They may contribute to stabilization of chromosome breaks, especially centric fissions, and increase the frequency of meiotic and illegitimate recombination.
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  • 16
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    Plant systematics and evolution 197 (1995), S. 59-69 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Lemnaceae ; Wolffia ; Allozymes ; genetic divergence ; electrophoresis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The genusWolffia was surveyed electrophoretically at 14 allozyme loci. A total of 133 clones representing 10 of the 11 recognized species was examined. Genetic identities among most pairs of species are zero, with non-zero values ranging from 0.14 to 0.40.Wolffia angusta and the newly describedW. neglecta show the highest similarity, and the former species has an identity of 0.14 withW. australiana. The next highest similarity (0.34) occurs betweenW. globosa of Southeast Asia andW. cylindracea of southern Africa, which until recently, had generally been viewed as members of the same species. Other species showing some common alleles are members of a complex involvingW. arrhiza, W. columbiana, W. cylindracea, andW. globosa. WithinW. arrhiza, plants from South Africa and Europe are easily distinguished electrophoretically because each contains unique alleles at two loci. Strains from other parts of Africa vary at these loci and are not totally distinct from either the plants from South Africa or from Europe. Species ofWolffia are much more divergent at allozyme loci than the majority of congeners of flowering plants. This suggests that the species are quite old and that the difficulties in distinguishing taxa morphologically are the result of reduction rather than lack of divergence due to recent speciation. Because of the lack of shared alleles between the majority of species pairs inWolffia, enzyme electrophoresis provides limited resolution of species relationships in the genus.
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  • 17
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    Plant systematics and evolution 198 (1995), S. 235-252 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Pollen ; pollen colour ; pollen signal ; spectral reflection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The spectral reflection of pollen in 67 plant species out of 28 families was measured by means of mass recording of pollen grains. Various types of spectral reflection curves were found, but 75% belonged to two categories: 1. Human-yellow pollen with strong reflection in the green and red, and low reflection in the ultraviolet and blue range of wavelengths. 2. Human-whitish pollen with strong reflection in the green and red and additional reflection of shorter wavelengths. It is shown that it is important to have information about the mode of the visual pollen display — crypsis or colour contrast against the corolla, pollen advertisement, or concealment — and the visual capabilities of the presumed pollinators in order to be able to discuss the signalling function of pollen colours.
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  • 18
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    Plant systematics and evolution 198 (1995), S. 253-265 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Asteraceae ; Lactuceae ; Microseris ; Chloroplast DNA ; Nuclear ribosomal DNA ; hybridization ; polyploidy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Seventy populations of North American annualMicroseris, Stebbinsoseris, andUropappus species were examined for chloroplast and nuclear ribosomal DNA restriction site variability to determine the origin of the allotetraploid speciesS. heterocarpa andS. decipiens. Previously identified chloroplast DNA restriction site variants were used in concert with restriction site variation forNco I in the nuclear-encoded ribosomal DNA repeat. The presence of two, mutually exclusive restriction site gains were observed in diploid populations ofM. douglasii; these same variants were also found in populations of allotetraploidS. heterocarpa, indicating mutiple origins of this species from different maternal diploid populations ofM. douglasii. Variation in the rDNA repeat between the diploid annual species and the putative paternal genome ofU. lindleyi was found to be additive inS. heterocarpa. A similar relationship was observed for the origin ofS. decipiens; cpDNA restriction site variants found inM. bigelovii andM. douglasii were present inS. decipiens. The rDNANco I variants also were additive in this purported allotetraploid. These results confirm the reticulate evolutionary pattern inStebbinsoseris and provide another example of multiple origins of intergeneric allopolyploids.
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  • 19
    ISSN: 1432-1432
    Keywords: CpG suppression ; GC content ; Angiosperms ; Isochores ; GC bias ; Mutational pressure ; Error-prone repair ; Transcriptionally coupled repair
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Nuclear protein coding sequences from gymnosperms are currently scarce. We have determined 4 kb of nuclear protein coding sequences from gymnosperms and have collected and analyzed 〉60 kb of nuclear sequences from gymnosperms and nonspermatophytes in order to better understand processes influencing genome evolution in plants. We show that conifers possess both biased and nonbiased genes with respect to GC content, as found in monocots, suggesting that the common ancestor of conifers and monocots may have possessed both biased and nonbiased genes. The lack of biased genes in dicots is suggested to be a derived character for this lineage. We present a simple but speculative model of land-plant genome evolution which considers changes in GC bias and CpG frequency, respectively, as independent processes and which can account for several puzzling aspects of observed nucleotide frequencies in plant genes.
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    Plant systematics and evolution 191 (1994), S. 83-104 
    ISSN: 1615-6110
    Keywords: Angiosperms ; androecium ; Merosity ; phyllotaxis ; pseudowhorl ; zygomorphy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The term merosity stands for the number of parts within whorls of floral organs, leaves, or stems. Trimery is considered to be a basic condition that arose through the cyclisation of a spiral flower. Pentamery is mostly derived from trimery by the repetitive fusion of two different whorls. Dimery is either directly derived from trimery, or through pentamery as an intermediate stage. Tetramery is linked with pentamery and should not be confused with dimery. Possible causes for a change in merosity are the reduction of the number of carpels and zygomorphy in flowers. Derivations of different merosities have important consequences for the arrangement of the androecium (the insertion of stamen whorls, their identifications, and their number). It is concluded that two main groups can be identified within the angiosperms: magnolialean and monocotyledonean taxa are mostly trimerous or dimerous; non-magnolialean dicots are mostly pentamerous or tetramerous.
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  • 21
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    Plant systematics and evolution 189 (1994), S. 165-191 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Rutaceae ; Zanthoxylum ; Fagara ; Flower morphology ; perianth ; gynoecium ; acrostylous and anacrostylous-basistylous carpels ; compitum ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The question whether the uniseriate perianth ofZanthoxylum L. s. str. is homologous with the calyx or the corolla of taxa included inFagara, or of an independent origin, has been controversial for a long time, but the arguments mostly have remained theoretical. The present investigation of floral structures indicates that there are two different types of uniseriate perianth inZanthoxylum s. str. Therefore, this taxon does not represent a natural group and should be united withFagara asZanthoxylum s.l. The infrageneric taxonomy of this genus is still very ambiguous. It is shown that differences in indumentum, number of sepals and petals (5-4-3) resp. perianth segments (4–9), stamens (3–6), and free carpels (1–5) are of systematic relevance. Particularly important but so far neglected is carpel shape, where an acrostylous and an anacrostylous-basistylous type can be recognized. Stigmata of 2 or more carpels mostly fuse to form a compitum. 4–5-merous flowers with calyx and corolla, and acrostylous carpels are considered as plesiomorphic character states in the genus. On the basis of ± corresponding morphological and phytochemical progressions a working hypothesis about the relationships withinZanthoxylum s.l. is presented in graphical form (Fig. 9).
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    Plant systematics and evolution 192 (1994), S. 177-197 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Leguminosae ; Leucaena esculenta ; L. leucocephala ; Hybridization ; sterile triploid ; morphometric analysis ; DNA characters ; restriction site analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Phytogeographical, morphological, and molecular evidence for the widespread but sporadic occurrence of sterile hybrids betweenLeucaena leucocephala subsp.glabrata andL. esculenta subsp.esculenta in South-Central Mexico is presented. Most morphological and DNA characters studied in the putative hybrids showed states intermediate between the proposed parental taxa. The occurrence of non-additive nuclear ribosomal DNA phenotypes is discussed and the need to use a suite of nuclear taxon-specific markers to determine hybridity is emphasized. The origin of the hybrid is discussed in relation to the disruption of the distributions of both parental taxa through use by man as minor food plants, providing another example of the important influence of human interference on the evolution ofLeucaena. The successful use of dried leaf material as a source of DNA is highlighted as an efficient way to identify sterile hybrids at the molecular level.
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    Plant systematics and evolution 193 (1994), S. 115-123 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Strelitzia ; Heliconia ; Typha ; Benincasa ; Epicuticular wax ; wax ultrastructure ; wax chemistry ; systematics ; taxonomy
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    Notes: Abstract Certain non-liliiflorous taxa within the monocotyledons (e.g.,Strelitzia, Heliconia, Typha) are characterized by compound epicuticular wax rodlets (Strelitzia type). Similar rodlets are also encountered on the surface of the dicotyledonous plantBenincasa hispida (Thunb.)Cogn. Chemical analysis of the surface wax from both sources showed that the rodlets are chemically distinct. The rodlets of the monocotyledons consist exclusively of aliphatic wax lipids, mainly wax esters. In contrast, the rodlets ofBenincasa are cheifly composed of triterpenol acetates and triterpenols. Formation of rodlets is therefore interpreted as ultrastructural convergency. It is concluded that taxonomical studies on wax crystalloids can be misleading when interpreted in terms of micromorphology of crystalloids only.
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    Plant systematics and evolution 190 (1994), S. 245-248 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Rubiaceae ; Chloroplast DNA ; atpB-rbcL intergene region ; phylogeny
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    Notes: Abstract Representatives of seven genera from five tribes ofRubiaceae have been compared in respect to a non-coding intergene cpDNA region of about 1000 bp, situated between the atpB and the rbcL genes. The resulting most parsimonious PAUP cladogram corresponds very well with one based on total cpDNA restriction site data obtained byBremer & Jansen (1991). The two different molecular analyses thus corroborate each other and contribute to an improved systematic arrangement of the large family, e.g., in respect to placing the tribeHedyotideae clearly into the subfamilyRubioideae, closer toRubieae than toPsychotrieae.
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    Plant systematics and evolution 192 (1994), S. 79-97 
    ISSN: 1615-6110
    Keywords: Angiosperms ; paleoherbs ; Magnoliidae ; Gnetales ; Floral evolution
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    Topics: Biology
    Notes: Abstract Concepts of primitive angiosperm flowers have changed in recent years due to new studies on relic archaic groups, new paleobotanical finds and the addition of molecular biological techniques to the study of angiosperm systematics and evolution.Magnoliidae are still the hot group, but emphasis is now on small primitive flowers with few organs and also on the great lability of organ number. Of the extant groups, a potential basal position of the paleoherbs has been discussed by some authors. Although some paleoherbs have a simple gynoecium with a single orthotropous ovule, anatropous ovules may still be seen as plesiomorphic in angiosperms. Anatropy is not necessarily a consequence of the advent of closed carpels. It may also exhibit biological advantages under other circumstances as is the case in podocarps among gymnosperms. Valvate anthers have now been found in most larger subgroups of theMagnoliidae (recently also in paleoherbs) and in some Cretaceous fossils. Nevertheless, as seen from its systematic distribution, valvate dehiscence is not necessarily plesiomorphic for the angiosperms, but may be a facultative by-product of the thick connectives and comparatively undifferentiated anther shape inMagnoliidae and lowerHamamelididae. A perianth is relatively simple in extantMagnoliidae or even wanting in some families. In groups with naked flowers the perianth may have been easily lost because integration in the floral architecture was less pronounced than in more advanced angiosperm groups. Problems with the comparison of paleoherb flowers with those ofGnetales are discussed. The rapid growth of information from paleobotany and molecular systematics requires an especially open attitude towards the evaluation of various hypotheses on early flower evolution in the coming years.
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    Plant systematics and evolution 187 (1993), S. 1-28 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Rutaceae ; Cytoevolution ; chromosome base numbers ; dysploidy ; polyploidy ; cladistics ; gondwanan forests ; heathlands
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    Notes: Abstract Chromosome numbers for 9 tribes and 73 genera ofRutaceae are examined for the probable chromosome base numbers in these taxa. There is abundant dysploidy and infrageneric polyploidy in the largeRutoideae/Toddalioideae complex. We found that x = 18 was typical for the tribesZanthoxyleae andToddalieae; probably ancestral in theBoronieae and perhaps in theRuteae, Diosmieae, andCusparieae; and characteristic of subfamilyFlindersioideae. Considering the basic position of elements ofZanthoxyleae andToddalieae in the family it appears that diploid x = 18 is ancestral in theRutaceae. The morphologically advancedCitroideae are invariant for x = 9 and may be a product of dysploid reduction.
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    Plant systematics and evolution 188 (1993), S. 115-123 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Polygonaceae ; Rumex acetosella ; R. acetosella subsp.angiocarpus ; Vegetative growth ; seed size ; population differentiation ; phenotypic plasticity
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    Notes: Abstract Vegetative growth patterns ofRumex acetosella L. were investigated both in experimental conditions and in the field. Plants originating from geographically and ecologically contrasting areas expressed significant differentiation in height, weight, and leaf production, even at early stages. The plants belonging to subsp.angiocarpus grew thaller than other plants. The differences among populations grown in a uniform environment provide evidence for genetic differentiation in morphology. Plants in natural populations were considerably lighter than experimental plants, which intensively produced a large number of rosette leaves. These differences can be attributed to substantial phenotypic plasticity. When the correlation structure among the growth traits was analyzed, seed weight and early plant size appeared to influence future plant size.
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    Plant systematics and evolution 187 (1993), S. 29-49 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Ranunculaceae ; Chloroplast DNA ; rearrangements ; mutation frequency ; phylogeny
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    Notes: Abstract Restriction site mapping of chloroplast DNA from 31 species representing 26 genera of theRanunculaceae was performed using eleven restriction endonucleases. The chloroplast genome varies in length from approximately 152 to 160 kb. Length variants are frequent in theRanunculaceae and range from usually less than 300 bp to rarely 1.5 kb. The inverted repeat is extended into the large single copy (LSC) region by 4–4.5 kb inAnemone, Clematis, Clematopsis, Hepatica, Knowltonia, andPulsatilla. Several inversions are present in the LSC-region of the cpDNA in all these genera and inAdonis. The frequency of restriction site mutations varies within the chloroplast genome in theRanunculaceae between 4 and 32 mutations per kilobase, and is lowest in the inverted repeat and the regions containing the ATPase-genes and the genespsaA, psaB, psbA, rpoB, andrbcL. A total of 547 phylogenetically informative restriction sites was utilized in cladistic analyses of the family using Wagner, Dollo, and weighted parsimony. These three parsimony analyses result in different tree topologies. Four, six, and one equally most parsimonious trees were obtained with Wagner, Dollo, and weighted parsimony, respectively. The amount of support for the monophyletic groups was evaluated using bootstrapping and decay analysis. All three parsimony methods suggest thatHydrastis is the sister group to the remainder of theRanunculaceae, and that theAnemone-Clematis group, which shares several derived cpDNA rearrangements, is monophyletic. Only a few of the traditional groups in theRanunculaceae are supported by cpDNA restriction side data. Only Dollo parsimony provides support for the hypothesis thatThalictroideae andRanunculoideae are monophyletic.
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    Plant systematics and evolution 184 (1993), S. 207-231 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Ericales ; Cladistics ; phylogeny ; taxonomy
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    Notes: Abstract A cladistic analysis of theEricales based on morphological, anatomical, embryological, and phytochemical data has been undertaken. Resulting from the analysis, 56 equally parsimonious cladograms were obtained. The tribeEnkiantheae was found to be the sister-group of the rest of theEricaceae, in which theEmpetraceae, theEpacridaceae, Pyrolaceae, andMonotropaceae are forming derived ingroups. It is thus concluded that theEricaceae are a paraphyletic assemblage as presently circumscribed, and thatEmpetraceae andEpacridaceae are better treated as members of theEricaceae.
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    Plant systematics and evolution 184 (1993), S. 41-76 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Steroids ; sterols ; ecdysones ; brassicanolides ; sapogenins ; saponins ; withanolides ; pregnanes ; cardenolides ; bufodienolides ; oxidation state ; skeletal specialization ; Sporne indices ; herbacity indices ; evolutionary steroid indices
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    Notes: Abstract The use of steroids as taxonomic markers of the angiosperms was evaluated. To this end evolutionary advancement parameters, based on oxidation state and skeletal specialization of each steroid were calculated. The averages of these values for the steroids registered for a particular plant group were assumed to represent the evolutionary parameters of the plant group. Positive correlations of these chemical parameters and of morphological Sporne indices, as well as of herbacity indices, were observed to constitute a general trend. Furthermore, steroids are not uniformly distributed within a morphologically homogeneous plant group, but are replacement characters. Thus, in spite of their functional importance, steroids can be considered, analogously to many other classes of secondary metabolites, for chemosystematic purposes.
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    ISSN: 1615-6110
    Keywords: Angiosperms ; Asteraceae ; Robinsonia ; Adaptive radiation ; chloroplast DNA ; ribosomal DNA
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    Notes: Abstract Restriction site mutations in the chloroplast (cpDNA) and ribosomal DNA (rDNA) were examined in 41 populations representing five of the seven recognized species of the genusRobinsonia, which is endemic to the Juan Fernandez Islands. No intraspecific variation was detected for cpDNA but one population of one of the species (R. evenia) had a restriction site mutation in rDNA not detected elsewhere. No restriction site mutations were unique to all species ofRobinsonia relative to the species ofSenecio used as outgroups. All 13 mutations (eight from cpDNA and five from rDNA) are restricted to single species, and thus provide no cladistically useful information within the genus. The distribution of mutations is concordant with the hypothesis of a rapid adaptive radiation ofRobinsonia subsequent to the dispersal of its ancestor to Masatierra.
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    Plant systematics and evolution 184 (1993), S. 259-283 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Asteraceae ; Astereae ; Cladistics ; evolution ; phylogeny ; classification
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    Notes: Abstract TheAstereae were surveyed and the genera arranged in 23 informal groups. The generic groups were used to sample representative genera for a cladistic analysis based on morphological characters. The resulting cladogram was used for discussion of evolution and subtribal classification within the tribe. The lower basic chromosome numbers x = 4, 5, 6, and 8 are interpreted as reductions from a primitive x = 9. The subtribeGrangeinae occupies a phylogenetically basal position as sister group to the rest of the tribe. This may be divided into two large groups, largely corresponding to the homochromousSolidagininae and to the heterochromousAsterinae sensu lato, i.e. including theBellidinae, Hinterhuberinae, Conyzinae, andBaccharidinae. The latter four subtribes are derived within theAsterinae, and hence reduced to synonymy. Several intercontinental relationships indicate that a geographical subdivision of the tribe should be avoided, although in our analysis most of the groups proved to be restricted to one of five major regions.
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    Plant systematics and evolution 185 (1993), S. 99-122 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Asclepiadaceae ; Periplocaceae ; Translator ultrastructure ; translator ontogenesis ; floral evolution
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    Description / Table of Contents: Zusammenfassung Ein wesentlicher Unterschied zwischen den beiden FamilienPeriplocaceae undAsclepiadaceae besteht in der Ausbildung der Translatoren, mit deren Hilfe der Pollen von Insekten übertragen wird. Bei denPeriplocaceae kleben die Pollentetraden an dem Translator, dieser selbst haftet mit einer basalen Klebscheibe am Kopf des Pollinators. DieAsclepiadaceae verzichten demgegenüber auf den Klebstoff, die Pollinien sind durch zwei Caudiculae mit einem Klemmkörper verbunden, der am Insekt klemmt. Im Zentrum dieser Arbeit steht die Frage, ob sich zwischen beiden Translatorformen Homologien finden lassen, die eine gemeinsame stammesgeschichtliche Herkunft begründen. Der Translator derPeriplocaceae besteht aus den drei Elementen Klebscheibe (adhesive disc), Stipes (stipe) und Pollenschaufel (spoon). Im typischen Fall sitzt der Stipes dorsal der Klebscheibe an, wodurch die Klebfläche selbst wie ein Stempel nach unten bzw. schräg nach außen gerichtet ist. Demgegenüber ist die geradlinige Anordnung von Stipes und Klebscheibe beiPeriploca graeca eine Ausnahme, die nicht als Basis für den Vergleich mit dem Asclepiadaceen-Translator dienen kann. In der Ontogenese wird der feste Teil der Klebscheibe, das Scutellum, zuerst angelegt und durch basale Sekretaddition als etwa rechtwinklig zur Griffelkopfoberfläche stehende Scheibe hinausgeschoben. Die Bildung des Scutellums erfolgt also von seiner Schmalseite aus. Im nächsten Schritt wird der Stipes-Ansatz am Scutellumrücken gebildet, auf diese Weise entsteht die gewinkelte Verbindung von Klebscheibe und Stipes. Der Anschluß der Pollenschaufel erfolgt etwas später ebenso wie die basale Verlängerung der Klebscheibe. Die Ontogenese zeigt, daß das primäre Element des Periplocaceen-Translators der obere Teil der Klebscheibe mit dem ihm dorsal ansitzenden basalen Stipesabschnitt ist. Innerhalb derAsclepiadaceae bilden die GattungenSecamone undFockea von den übrigen Gattungen abweichend gestaltete Translatoren aus, bei denen die Pollinien nicht an seitlichen Caudiculae, sondern an einer dorsalen Platte befestigt sind. Der morphologische Vergleich ergibt, daß die Translatoren beider Gattungen ausgeprägt plesiomorphe Züge tragen und als Zwischenformen zwischen dem Periplocaceen-Translator und dem elaborierten Asclepiadaceen-Translator angesehen werden können. Der Translator vonSecamone läßt sich mit dem primären Scutellum-Stipes-Komplex derPeriplocaceae homologisieren. Der Klemmkörper selbst entspricht einem nach vorn zusammengeschlagenen Scutellum, der die Pollinien tragende Dorsalfortsatz dem basalen Stipes. Für diese Homologisierung spricht nicht nur die relative Lage der Elemente der verglichenen Translatoren, sondern insbesondere ihre in den Grundzügen übereinstimmende Ontogenese. Von ausschlaggebender Bedeutung ist dabei die von der Schmalseite her erfolgende Bildung des Scutellums, die in der von der Basis aus fortschreitenden Anlegung desSecamone-Klemmkörpers ihre Entsprechung findet. Der Translator der GattungFockea stellt im Sinn des Stetigkeitskriteriums eine Zwischenform zwischen denSecamoneae und den elaboriertenAsclepiadaceae dar. Ohne diese Zwischenform wäre der morphologische Zusammenhang der Translatoren beider Taxa kaum zu belegen.Fockea stimmt mitSecamone in der Ausbildung des dorsalen Fortsatzes zur Pollinienanheftung wie auch in der Anheftung des adulten Translators an die Leitschiene mit Hilfe basaler Klebflächen überein. Eine Weiterentwicklung zeigtFockea in der Verlängerung des Translators parallel zur Griffelkopfoberfläche, die mit einer anfänglichen neuen Bodenbildung einhergeht. Diese neue Längsachse wie auch eine ausgeprägte Bodenstruktur sind charakteristisch für die Translatoren höher entwickelter Asclepiadaceen. Als auffälligstes Unterscheidungsmerkmal kommt bei ihnen die Befestigung der Pollinien mit Hilfe zweier Caudiculae hinzu. Aufgrund fehlender Zwischenstufen ist die phylogenetische Herkunft der Caudiculae bisher nur hypothetisch lösbar. Eine Ableitung von basalen Klebflächen wie etwa beiFockea wird für wahrscheinlich gehalten. Damit sind im elaborierten Asclepiadaceen-Translator nur noch Andeutungen von Elementen zu finden, die mit dem Translator vonSecamone homologisiert werden könnten. Nach den vorliegenden Untersuchungen erscheint der Entwicklungsschritt von der Periplocaceen-Stufe zum einfachsten Klemmkörper derAsclepiadaceae beiSecamone wesentlich geringer als die Evolution des Translators innerhalb derAsclepiadaceae selbst.
    Notes: Abstract This paper deals with the problem of homology between the translators inPeriplocaceae andAsclepiadaceae. Since most differences between the flowers in both families are based on the functional differences in the pollination process, it seems that the question of common ancestry can best be solved by clarifying the problem of the evolution of the translator itself. Ontogenetic investigation has revealed that the central element of the periplocoid translator is the adhesive disc together with the base of the stipe. The translator inSecamoneae (the most primitive tribe inAsclepiadaceae) is homologous to this element, and inSecamone the adhesive disc is transformed into the corpusculum while the stipe is represented by the dorsal process to which the pollinia are attached. The translator in the genusFockea represents an intermediate stage in the further phylogenetic elaboration of the asclepiad translator. It corresponds toSecamone in the development of a dorsal process for the attachment of the pollinia and in the special mode by which the corpusculum is attached to the anther wings. On the other hand, the elongated shape and the formation of a floor in the corpusculum are derived traits pointing to the more highly evolvedAsclepiadaceae, such as theAsclepiadeae. The question of the derivation of the caudicles is discussed and a hypothesis concerning their development from pre-adaptive elements inFockea is put forward. General conclusions are 1. thatPeriplocaceae andAsclepiadaceae are sister groups and that the common ancestor possessed a primitive translator composed of at least the two elements adhesive disc and stipe; 2. that the morphological difference of the translators betweenPeriplocaceae andSecamone is smaller than betweenSecamone and the more advancedAsclepiadaceae.
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    ISSN: 1432-2242
    Keywords: DNA fingerprinting ; Repetitive DNA ; Genotype identification ; Angiosperms
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    Notes: Summary Oligonucleotides hybridizing to simple repetitive DNA patterns are highly informative as probes for DNA fingerprinting in all investigated animal species, including man. Here we demonstrate the applicability of this technique in higher plants. The oligonucleotide probes (GTG)5 and (GATA)4 were used to investigate the differences in DNA fingerprint patterns of the following angiosperm species: Triticum aestivum, Secale cereale, Hordeum vulgare, Beta vulgaris, Petunia hybrida, Brassica oleracea, and Nicotiana tabacum. Two species, Hordeum vulgare as a monocot and Beta vulgaris as a dicot, were analyzed in more detail. Their genomes differ considerably in both amount and organization of the simple repetitive sequences (GATA)n, (GACA)n, (GTG)n, and (CT)n due to the evolutionary distance of these two species. Furthermore, several lines and cultivars of Beta vulgaris and Hordeum vulgare can clearly be distinguished on the basis of their highly polymorphic patterns of these repetitive sequences.
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    Sexual plant reproduction 5 (1992), S. 86-88 
    ISSN: 1432-2145
    Keywords: Sex chromosome markers ; Y-chromosome ; Angiosperms ; Silene latifolia ; Melandrium album
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    Notes: Summary In order to obtain markers for the Y chromosome ofSilene latifolia, we pooled equal weights of leaf tissue from 18 female siblings into one sample and repeated the process with 18 male siblings. Pooling was intended to provide a common genetic background for each sample, leaving the absence or presence of the Y chromosome as the primary difference between the two samples. DNA was extracted from each sample and subjected to polymerase chain reaction (PCR) amplification with arbitrary 10 bp primers. Four of 60 primers used gave an amplification with the male DNA not found among those from the female DNA. Each of these was subsequently shown to provide a reliable marker for the Y chromosome.
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    Plant systematics and evolution 182 (1992), S. 107-119 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Piperaceae ; Peperomia ; Flavonoids ; cytology ; phenetics ; cladistics ; Flora of the Juan Fernandez Islands ; Chile
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    Notes: Abstract Four species ofPeperomia (Piperaceae) occur in the Juan Fernandez Islands, Chile:P. berteroana, P. margaritifera, P. skottsbergii, andP. fernandeziana. The last species is found also in continental Chile, whereas the other three are endemic to the archipelago.Peperomia margaritifera is found only on the older island of Masatierra, whereasP. skottsbergii is confined to the younger island of Masafuera, andP. berteroana occurs on both islands. Phenetic analyses of mainland taxa suggest thatP. fernandeziana belongs to subg.Sphaerocarpidium whereas the endemic taxa form their own subg.Tildenidium connecting to subg.Tildenia. Cladistic analyses indicate thatP. margaritifera is the most primitive species in the archipelago and thatP. berteroana is the most derived, especially patristically. Chromosomally, the four species are all n = 22, which may be tetraploid on a base of x = 11. Sulfated flavones occur only inP. berteroana andP. skottsbergii, which are otherwise unknown for the family. Dispersal of propagules to the islands from the continent and between islands is believed to have been accomplished by birds.
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    Plant systematics and evolution 179 (1992), S. 43-58 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Orchidaceae ; Orchis morio subsp.morio ; O. morio subsp.picta ; O. longicornu ; Multilocus electrophoresis ; genetic variation ; gene flow ; morphology ; Flora of Italy
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    Notes: Abstract Data are presented on genetic variation at 27 enzyme loci of the Green-Winged orchid,Orchis morio, in 18 population samples from Italy. The existence in Italy of two subspecies, i.e. subspp.morio andpicta, is not supported by allozyme data. No genetic heterogeneity was found betweenmorio-like andpicta-like samples and specimens. Moreover, morphological transition between the two forms was observed in different Italian populations. The parameters of genetic variability estimated forO. morio populations are consistent with those found among monocotyledon plants, and among those outcrossing, animal-pollinated and with wind-dispersed seeds. Genetic diversity of ItalianO. morio is mostly within populations. Correspondingly, low values of interpopulational genetic distance were found. This appears to be due to high levels of gene flow, which were estimated with different methods. The lack ofO. longicornu from Italian samples, as well as of any hybrid withO. morio (F1, backcrossed or recombinant individuals) is demonstrated on the basis of genetic data. It is concluded that recurrent reports ofO. longicornu from Italy are due to confusion withO. morio or with otherOrchis species.
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    Plant systematics and evolution 179 (1992), S. 95-105 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Orchidaceae ; Epidendreae ; Malaxidinae ; Malaxis saprophyta ; Embryology ; systematics
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    Notes: Abstract InMalaxis saprophyta, anther wall development corresponds to the Monocotyledonous type. The uninucleate tapetum is of secretory type and the endothecium develops U- and V-shaped thickenings on the inner tangential and radial walls. Cytokinesis is simultaneous; tetrahedral, isobilateral and T-shaped tetrads are formed which are compactly aggregated in pollinia. At anthesis the microspore tetrads are 2-celled. The ovule is anatropous, bitegmic and both integuments are dermal in origin. A single hypodermal cell develops directly into a megaspore mother cell. Embryo sac development is predominantly monosporic and less often bisporic. Irrespective of the type of development, the mature embryo sac is 6-nucleate. Although double fertilization occurs, the primary endosperm nucleus degenerates. Embryogeny is of the Onagrad type. The mature embryo lacks differentiation into cotyledon, plumule and radicle. The reticulate seed coat is formed entirely by the outer layer of outer integument. There are three sterile and three fertile valves in the ovary. Although initially parenchymatous, the entire three sterile valves in the ovary and the upper half of the three fertile valves become sclerified after fertilization. The embryological characters support the disputed systematic position ofMalaxis within subtribeMalaxidinae ofEpidendreae.
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    ISSN: 1615-6110
    Keywords: Angiosperms ; Poaceae ; Aegilops ; Genome D cluster ; alpha-gliadins ; storage proteins ; phylogeny ; introgression ; electrophoresis ; restriction enzyme analysis
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    Notes: Abstract The D genome cluster includes six allopolyploidAegilops species having as pivotal genome that ofAegilops squarrosa. Alpha-gliadins, endosperm proteins coded by multigenic families, have been analyzed in the D genome species cluster and in their putative progenitors. They can be present or weakly expressed when analyzed in acid polyacrylamide gel electrophoresis. Molecular analysis has shown the possibility to distinguish subsp.strangulata from subsp.eusquarrosa and to confirm the presence ofAe. caudata and ofAe. umbellulata in the polyploidsAe. cylindrica andAe. juvenalis, respectively. Finally, introgression fromAe. longissima orAe. searsii in tetraploid and hexaploidAe. crassa, Ae. juvenalis, andAe. vavilovii is supposed.
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    ISSN: 1615-6110
    Keywords: Angiosperms ; Eriotheca ; Bombacaceae ; Anthophoridae ; Neotropical savanna ; bee pollination ; polyembryony ; apomixis ; polyploidy
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    Notes: Abstract The pollination biology and breeding systems ofEriotheca pubescens andE. gracilipes have been studied. These two species occur as trees in cerrado vegetation, the neotropical savannas of Central Brazil, with partially sympatric distributions. They have similar phenology and floral structure, although the flowers ofE. pubescens are larger. Both species have nectar flowers pollinated by largeAnthophoridae bees but the main pollinators of each species differ in size. The species have markedly different breeding systems: late-acting self-incompatibility inE. gracilipes and apomixis stimulated by pollination inE. pubescens.
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    Plant systematics and evolution 180 (1992), S. 1-13 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Poaceae ; Triticeae ; Elymus ; Genome analysis ; morphology ; taxonomy
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    Notes: Abstract Seven tetraploid species ofElymus, viz.E. sibiricus, E. caninus, E. gmelinii, E. semicostatus, E. caucasicus, E. parviglume, andE. longearistatus subsp.canaliculatus, representing five sections were studied morphologically and used in interspecific hybridizations. The aim was to investigate whether the present sectional delimitation of the genus was in agreement with genomic data and if there was a correlation between genome constitution and morphology. The study revealed: (i) further information on the genomic affinities between the different species, (ii) that there is no congruence between genome constitution of the species and current sectional delimitation, and (iii) that there is a correlation between genome constitution and morphology in the palea apex shape and in the size of cilia of the palea.
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    Plant systematics and evolution 179 (1992), S. 175-185 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Gramineae ; Deschampsia cespitosa ; Zinc tolerance ; heavy metal ; tolerant populations ; genetic basis ; heritability
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    Notes: Abstract Patterns of zinc tolerance were examined in eightDeschampsia cespitosa (L.)Beauv. populations from normal and zinc-contaminated soils, using solution culture methods. Zinc-tolerant populations have evolved beneath pylons, and their tolerance patterns (degree, variance, heritability) vary. Tolerance is genetically based in all of them. In contrast to the cases of other species previously reported, some within-population differences are considerable, and may be due to both heterogeneity of the soils zinc contents, various gene combinations and gene recombinations between genotypes. One control population contains many tolerant plants, an original result which is discussed.
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    Plant systematics and evolution 180 (1992), S. 15-28 
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    Keywords: Angiosperms ; Cruciferae ; Erysimum ; Multivariate analysis ; cladistics
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    Notes: Abstract A taxonomically difficult purple-flowered group within the genusErysimum, restricted to the Iberian Peninsula, is analyzed by multivariate and cladistic analyses. 51 specimens have been scored for 14 characters. Both principal components and discriminant analyses provide support to the recognition of the five species considered by the author, namelyE. linifolium, E. lagascae, E. baeticum, E. popovii, andE. cazorlense. Cladistic analysis, using 7 characters resulted in a single most parsimonious cladogram containing no homoplasies. The pattern of morphologic divergence follows a clear NW.-SE. trend, which is congruent with the topology of the cladogram. This trend significantly affects growth-form as well as fruit characters, both providing the main grounds for species recognition. The different behavior and significance of several characters in both kinds of analysis is discussed. The co-occurrence of morphologically similar individuals differing in the flower color is discussed, too. Possible explanations for this phenomenon involve hybridization in a wide sense or, alternatively, rejecting the assumption of monophyly for the group.
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    Plant systematics and evolution 180 (1992), S. 137-156 
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    Keywords: Angiosperms ; evolution ; origin ; ancestral angiosperm ; morphology
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    Notes: Abstract The ancestral angiosperm is commonly interpreted as an arborescent to shrubby magnolialean with large, multiparted, complex flowers. We examined this hypothesis using a phylogenetic analysis of new and reevaluated characters polarizabled with outgroup comparison. Our cladistic analysis of basal angiosperms placed the nonmagnolialeanChloranthaceae andPiperaceae at the bottom of the tree. We further inferred the probable ancestral states of characters not polarizable with outgroup comparison by examining their distribution among taxa at the base of our cladogram. The sum of ancestral character states suggests that the protoangiosperm was a diminutive, rhizomatous to scrambling perennial herb, with small, simple flowers.
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    Plant systematics and evolution 181 (1992), S. 97-108 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Campanula ; Pollination biology ; pollen germinability ; pollen collecting hairs ; self-compatibility
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    Notes: Abstract Pollination mechanisms within the genusCampanula were studied. Tests were undertaken to examine whether in vitro culture of pollen grains can serve as a useful tool for understanding the self- and cross-pollination mechanisms among species. Characteristics of pollen germination were interpreted in relation to mating system and floral biology. Four annual species (Campanula kremeri, C. dichotoma, C. afra, C. lusitanica), and two perennial species (C. rotundifolia andC. persicifolia) were investigated. In the annual species pollen germinability is controlled by (1) the age of pollen and/or (2) in what position pollen is deposited around the style. Correlations were found between pollen germinability and mating system in three of the four annual species. No correlations were found either between germinability and age of pollen or position on the style in the perennial species. Pollen germinability reached its maximum in the middle of the male phase in all species, except forC. dichotoma, which had a decreasing germinability throughout anthesis. The germinability was lowest at the time of stigma receptivity for all species except forC. persicifolia, where the stigma did not develop as long as pollen remained on the style. The pollen collecting hairs and pollen removal have been found to play an important role controlling the stigma development, thus affecting self-pollination. This was especially pronounced inC. persicifolia. Further studies will be undertaken to elucidate factors influencing pollination within the genusCampanula.
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    Plant systematics and evolution 181 (1992), S. 133-141 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Thymelaeaceae ; Thymelaea hirsuta ; Dioecy ; heterodichogamy ; sex ratio ; breeding system
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    Notes: Abstract The sex expression inThymelaea hirsuta was assessed in five habitats in the western Mediterranean desert of Egypt. The survey over two main flowering periods indicated that the sexual expression of this plant is complex and labile. Beside the dioecious male and female states, five monoecious states were detected. The dioecious states are more abundant and less labile. There is a clear shift from monoecious towards dioecious states and in general favour of males from the first (late autumn) to the second (late winter) flowering period. These results are discussed in view of the adaptive theories and evolution.
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    Plant systematics and evolution 183 (1992), S. 51-65 
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    Keywords: Angiosperms ; Melittophily ; flower colour ; colour signal ; UV-pattern ; spectral purity ; colour saturation
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    Topics: Biology
    Notes: Abstract In melittophilous plants the colour pattern of the flowers, as perceived by bumblebees, is a gradient of centripetally increasing spectral purity. This pattern serves as a signal for innate flower recognition in naive bumblebees permitting orientation to flowers and landing on flowers. Structures which make up the total signal pattern can include the background (e.g., green leaves), corollas, and stamens or floral guides. How various colour parameters, such as dominant wavelength, intensity, and spectral purity influence the colour signal pattern of flowers is analyzed. The process of strong absorption of ultraviolet light is shown to be a mechanism for the enhancement of spectral purity in flower guides. The importance of other mechanisms is also demonstrated. The presence of a gradient of centripetally increasing spectral purity in floral colour patterns as perceived by a bumblebee's eyes is demonstrated by a comparison of the spectral reflectance in different parts of the flower and a representation of colour loci in the colour triangle.
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    Plant systematics and evolution 183 (1992), S. 169-181 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Plant 5S DNA ; spacer variation ; sequence conservation
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    Notes: Abstract The DNA sequence properties of 5S DNA (5S RNA gene plus spacer) from a wide range of families of plants is reviewed with particular reference to the possibility of using the information for phylogenetic inference. Although the data-base is extremely limited, the available evidence suggests that within a subclass or tribe phylogenetic inference can be made, provided that a knowledge about the number of chromosomal locations of the gene loci (5S Dna loci) is available. The evidence suggests little, if any, exchange occurs between the 5S DNA units at different chromosomal loci and the available data favour a mechanism involving amplification/deletion processes for creating structural changes at the5S Dna loci. Sequences originating from species in the familiesRosaceae, Poaceae, andBrassicaceae tended to group together in cladistic analyses but with low confidence limits. Surprisingly little of the spacer region showed conservation of sequence that may relate to a function in the control of transcription by RNA polymerase III.
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    Plant systematics and evolution 180 (1992), S. 105-114 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Poaceae ; Aegilops comosa subsp.comosa var.comosa ; C-banding pattern polymorphism
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    Notes: Abstract The Giemsa C-banding pattern of the chromosomes of the native self-pollinatedAegilops comosa subsp.comosa var.comosa was studied. Six of the seven chromosomes of the haploid genome were found to be polymorphic for C-banding patterns. Chromosome A had four variants, chromosome E three variants and each of the chromosomes B, D, and F two variants. Chromosomes E and G were polymorphic for arm length and arm ratio.
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    Plant systematics and evolution 179 (1992), S. 19-25 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Fabaceae ; Ulex ; Isoenzymes ; crossed immunoelectrophoresis ; seed proteins ; hybridization
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    Notes: Abstract Prostrate ecotypes ofUlex gallii, an atlantic species with autumnal flowering, grow on capes in Brittany (France).U. europaeus, a widespread species, has winter and spring flowering, but some plants can precociously flower in autumn, so that hybridization can be possible between these two species in areas where their ranges overlap. By using different isoenzyme systems and crossed immunoelectrophoresis obtained with seed proteins, it is possible to consider plants with intermediate morphological characters betweenU. gallii andU. europaeus as natural hybrids.
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    Plant systematics and evolution 179 (1992), S. 59-71 
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    Keywords: Angiosperms ; Scrophulariaceae ; Rhinanthoideae ; Rhinantheae—Euphrasinae ; Nothobartsia aspera ; N. spicata ; Bartsia ; Odontites ; Euphrasia ; Cladistics ; taxonomy
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    Notes: Abstract Recent systematic studies ofBartsia andOdontites showed the necessity to exclude the closely related perennial speciesBartsia aspera (Portugal and northern Morocco) andBartsia spicata (Central Pyrenees) from the genusBartsia as a segregate genus namedNothobartsia. Morphologically this new genus combines characteristic features ofBartsia and ofOdontites. Its autonomous systematic position is supported by the cladistic analysis, showing thatNothobartsia represents a relatively primitive genus standing close to the common ancestral root ofBartsia, Euphrasia, andOdontites.
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    Plant systematics and evolution 179 (1992), S. 89-93 
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    Keywords: Angiosperms ; Rhamnaceae ; Condalia microphylla f.melanocarpa ; C. microphylla f.erythrocarpa ; C. microphylla f.xanthocarpa ; C. buxifolia ; C. montana ; Fatty acids ; alkanes ; chemotaxonomy
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    Notes: Abstract The alkane and fatty acid composition of the lipid extracts from leaves of 14 populations ofCondalia: C. microphylla f.xanthocarpa, C. microphylla f.erythrocarpa, C. microphylla f.melanocarpa, C. montana, andC. buxifolia, were determined by gas chromatography. Seventeen alkanes and 14 fatty acids were investigated and a predominance of nonacosane, hentriacontane, palmitic and linoleic acids in all species was found.
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    Plant systematics and evolution 179 (1992), S. 155-165 
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    Keywords: Angiosperms ; Poaceae ; millets ; Homogeneous/heterogeneous repeat families ; fossil repeats ; genome turnover
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    Notes: Abstract Based on optical reassociation studies of total nuclear DNAs at 55°C, 62°C, 69°C, and 75°C, it is concluded that repeat families in great millet, little millet, barn yard millet and finger millet are heterogeneous while those of fox tail millet are homogeneous. In great millet, almost one third of the sequences that behave as single copy at standard conditions are actually fossil repeats. Such “fossil” repeats are not a prominent feature of the genomes of the other four millets. The ratios of sequence complexities of repeats isolated at 75°C to those isolated at 55°C are 2.2, 3.5, 81, and 0.3 in case of little millet, finger millet, fox tail millet, and great millet respectively. On the basis of the above three observations, it is suggested that among these millets, the rate of turnover of the genome of fox tail millet is the slowest while that of great millet is the fastest. Such comparative estimates of differences in the turnover rates of genomes of related species are expected to generate useful data about the evolution of genomes.
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    Keywords: Angiosperms ; Ericaceae ; Arctostaphylos ; Meiotic pairing patterns ; polyphyletic allopolyploidy ; morphometrics
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    Notes: Abstract The central Sierran tetraploidArctostaphylos mewukka Merriam has been reported to be an allopolyploid originating from the diploid species,A. patula Greene and eitherA. viscida subsp.viscida Parry orA. viscida subsp.mariposa (Dudley)P. V. Wells, although without conclusive evidence. Morphometrics and the verification and determination of chromosome numbers were used to substantiate the evolutionary relationships among these species. A closely related species,Arctostaphylos truei Knight, was also examined using these methods to determine its separability fromA. mewukka. The morphometric analyses support a hypothesis for a polyphyletic origin ofA. mewukka from different races ofA. viscida andA. patula. The chromosomal data, although inclusive, also support this hypothesis. The data do not support the recognition ofA. truei as a taxonomic entity separate fromA. mewukka at the species level.
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    Plant systematics and evolution 179 (1992), S. 167-174 
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    Keywords: Angiosperms ; Compositae ; Senecio vulgaris ; S. vernalis ; S. squalidus ; Ancestry ; autopolyploidy ; allopolyploidy ; isozyme variation
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    Notes: Abstract An electrophoretic survey of isozyme variation was conducted to test the hypothesis thatSenecio vulgaris L. (2n = 40) is of autotetraploid origin fromS. vernalis Waldst. & Kit. (2n = 20). It was established thatS. vulgaris exhibited fixed heterozygosity at three loci examined, showed disomic inheritance at all polymorphic loci, and contained a gene (αEst-1) and an allele (Aat-3b) which were not present in the single population ofS. vernalis surveyed. From this it is concluded thatS. vulgaris is not of autotetraploid origin. Instead, the genetic evidence is in keeping with an allopolyploid origin ofS. vulgaris with the possibility thatS. vernalis acted as one of its two parents.
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    Plant systematics and evolution 181 (1992), S. 45-55 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Alliaceae ; Allium ; Chloroplast DNA ; ribosomal DNA ; phylogeny ; bulb onion ; bunching onion ; chive ; garlic ; leek
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    Notes: Abstract Estimates of the phylogenetic relationships among cultivated and wildAllium species would benefit from identification of objective molecular characters. Restriction fragment length polymorphisms in the nuclear 45s ribosomal DNA (rDNA) were identified among two of five accessions of each of six cultivated Alliums. Restriction enzyme sites forBamHI,DraI,EcoRI,EcoRV,SacI, andXbaI were mapped. Different lengths of the rDNA repeat unit among the cultivated Alliums were due to sizes of the intergenic spacer. Nineteen polymorphic restriction enzyme sites were discovered and used to estimate phylogenetic relationships. Cladistic analyses based on Wagner parsimony were completed without an outgroup and resulted in two equally most parsimonious trees of 22 steps. A combined analysis of differences at RE sites in the ribosomal (19 characters) and chloroplast (15 characters) DNA generated a single most parsimonious tree of 39 steps. Single trichotomies were observed at 40 and 41 steps. Strict consensus of the three trees of 41 or fewer steps consisted of a lineage forA. tuberosum, a second forA. ampeloprasum andA. sativum, and a third forA. cepa, A. fistulosum, andA. schoenoprasum. Estimates of phylogenetic relationships based on variability at restriction enzyme sites in the rDNA and chloroplast DNA agree with the classification scheme ofTraub. Because of the predominance of autapomorphies, restriction enzyme analysis of the nuclear 45s rDNA is of limited use in estimating phylogenies amongAllium sections. However it is useful in the establishment of interspecific hybridity.
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    Plant systematics and evolution 180 (1992), S. 227-233 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Menyanthaceae ; Villarsia lasiosperma ; Breeding system ; heterostyly ; distyly
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    Notes: Abstract The restricted perennial diploid herb,Villarsia lasiosperma, of southwestern Western Australia has distylous flowers with dimorphism in style and stamen length, stigma morphology, and pollen size. In order to assess the presence and nature of an incompatibility system in this species, a crossing program was carried out using 17 plants grown from seeds collected in two field populations. Pollen stainabilities of these plants mostly exceeded 95%. Mean seed-set of Longs following intermorph pollinations was c. 24 seeds per pollination and for Shorts was c. 16 seeds per pollination. Approximately three-quarters of the Longs and Shorts produced no seeds after self-pollination; the remainder produced very few seeds following such pollinations. No Shorts produced seeds after intramorph cross-pollinations. However, about half the Longs exhibited various levels of weakened intramorph incompatibility, with mean seed-sets following intramorph cross-pollinations up to half the mean seed-sets following intermorph pollinations. In the behavior of Longs, the incompatibility system ofV. lasiosperma differs from the idealized distylous breeding system, but resembles that of a purported close relative,V. exaltata of eastern and southeastern Australia.
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    Plant systematics and evolution 180 (1992), S. 29-52 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Polygonaceae ; Fallopia ; Reynoutria ; Chromosome number ; microdensitometry ; meiosis ; hybridisation ; dioecism ; alien plants
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    Notes: Abstract The taxa in this study have in the past been treated together in sect.Tiniaria Meissner ofPolygonum L. s.l., and more recently the large erect rhizomatous herbaceous perennials have been separated from the twining annuals and perennials as the generaReynoutria andFallopia respectively. These taxa range in ploidy level from diploid to octoploid, with base numbers of both 10 and 11 present. The plants are primarily Asiatic in distribution, although many of the large erect perennials are now naturalized in many parts of Europe. Cytological examination has revealed the presence of a number of previously unknown hybrid taxa in the British Isles. The readiness with which hybridisation occurs between taxa of differing base number and ploidy level, and similarities revealed in chromosome morphology, meiotic pairing and in DNA C-value, suggest to the authors that these two genera are best amalgamated underFallopia.
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    Plant systematics and evolution 180 (1992), S. 53-64 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Euphorbiaceae ; Macaranga ; Ant-plant interactions ; domatia ; evolution ; myrmecophytism ; Flora of Malaysia
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    Notes: Abstract The paleotropical tree genusMacaranga (Euphorbiaceae) comprises all stages of interaction with ants, from facultative associations to obligate myrmecophytes. In SE.-Asia food availability does not seem to be the limiting factor for the development of a close relationship since all species provide food for ants in form of extrafloral nectar and/or food bodies. Only myrmecophyticMacaranga species offer nesting space for ants (domatia) inside internodes which become hollow due to degeneration of the pith. Non-myrmecophytic species have a solid stem with a compact and wet pith and many resin ducts. The stem interior of some transitional species remains solid, but the soft pith can be excavated. The role of different ant-attracting attributes for the development of obligate ant-plant interactions is discussed. In the genusMacaranga, the provision of nesting space seems to be the most important factor for the evolution of obligate myrmecophytism.
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    Plant systematics and evolution 180 (1992), S. 221-225 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Acanthaceae ; Ruellia ; Speciation over short distances ; endemism ; taxonomy ; Flora of Mexico
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    Notes: Abstract A new section in MexicanRuellia, R. sect.Urceolata comprising three species (includingR. cedilloi, spec. nova), endemic to Mexico, is described and illustrated. The taxonomic relationship and differentiation of the species are discussed. Evolution in Mexican Ruellas seems to be occurring at the diploid level.
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    Plant systematics and evolution 181 (1992), S. 143-169 
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    Keywords: Angiosperms ; Rubiaceae ; Tocoyena ; Hybridization ; differentiation ; speciation ; homogamic complex ; tropical woody plants ; taxonomy ; Flora of South America
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    Notes: Abstract The variation pattern of a large population ofTocoyena formosa in Botucatu, state of São Paulo, Brazil, and of other samples throughout the species area was analysed by morphometrical, statistical, ecological, and phytogeographical methods. Excessive variation and the remarkable coherence of two different character syndromes within this species strongly suggest that it has originated as a homogamic (diploid) hybrid complex. Possible parental species areT. brasiliensis, mainly from the Amazon region, andT. viscidula from the dry caatinga region of NE. Brazil.T. formosa has a much more extensive geographical range and greater ecological plasticity, ranging from the Amazon basin and the Guyanas throughout the Central Brazilian Plateau and from NE. to S. Brazil and Paraguay. Three (partly sympatric) varieties are distinguished withinT. formosa, i.e. var.formosa, var.pseudobrasiliensis (var. nov.), and var.microdon (comb. et stat. nov.). A provisional taxonomic revision, key, and conspectus covers the 12 accepted species ofTocoyena with blunt flower buds and ovate obtuse corolla lobes (group A, includingT. formosa); their distribution is shown in a map.
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    Plant systematics and evolution 181 (1992), S. 203-216 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Saxifragaceae ; Tiarella trifoliata ; Intraspecific cpDNA variation ; biogeography ; phylogeography
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    Notes: Abstract Tiarella trifoliata comprises varietieslaciniata, trifoliata, andunifoliata, and is distributed from southeastern Alaska to northern California. We analyzed restriction site variation of chloroplast DNA (cpDNA) using 23 endonucleases in 76 populations representing the entire geographic range of the species and the three recognized varieties. We also employed comparative restriction site mapping of PCR-amplified chloroplast DNA fragments using 16 restriction endonucleases. This species exhibits low cpDNA restriction site variation. No differentiation is evident among varieties of this species based on cpDNA data; some plants of each variety were characterized by each of the two major cpDNA types detected. The two major cpDNA clades, which differ by only a single restriction site mutation, are geographically structured. A northern clade comprises populations from Alaska to central Oregon; most populations analyzed from southern Oregon and California form a southern clade. Populations that possess the typical northern cpDNA type also occur disjunctly to the south at high elevations in the Siskiyou—Klamath Mountain area of southern Oregon and northern California. Conversely, the southern cpDNA type is found disjunctly to the north in the Olympic Peninsula of Washington. Both geographic areas characterized by disjunct cytoplasms are considered glacial refugia.Tiarella trifoliata joins two other species,Tolmiea menziesii andTellima grandiflora, in having well-demarcated northern and southern cpDNA lineages. All three species have similar life-history traits and geographic distributions. We suggest that glaciation may have played a major role in the formation of the cpDNA discontinuities present in these three taxa. The pronounced relationship between cpDNA variation and geographic distribution suggests the potential applicability of “intraspecific phylogeography” to plants via the analysis of intraspecific cpDNA variation. These three examples also join a rapidly growing data base which indicates that cytoplasms are often geographically structured within species and species complexes.
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    Plant systematics and evolution 179 (1992), S. 245-256 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Cistaceae ; Cistus ; Halimium ; Helianthemum ; Fumana ; Tuberaria ; Outcrossing ; autogamy ; cleistogamy ; shrublands ; Flora of Spain
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    Notes: Abstract Fourteen common southern Spanish species in theCistaceae were examined for quantitative variations in floral traits. These included the diameter of the corolla, number and size of anthers, number of ovules, and the size and shape of the gynoecium. The variables were in most instances positively correlated, species with larger flowers having more and larger anthers, more ovules, etc. Shrubs were observed to possess the largest, annuals the smallest, and subshrubs medium-sized flowers. Detailed observations of flower structure and function in a shrub (Cistus salvifolius), a spring-annual (Tuberaria guttata) and a winter-annual (T. inconspicua), revealed substantial variations in the breeding system. WhileC. salvifolius (and probably most woody species in this family) presents self-incompatibility, annual species ofTuberaria are self-compatible. In the studied population,T. inconspicua plants bore only reduced, cleistogamous flowers with no sign of a corolla.T. guttata has chasmogamous flowers that can facultatively self-pollinate.
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    Plant systematics and evolution 179 (1992), S. 1-18 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Asteraceae ; Centaurea ; Acrocentron ; Karyology ; biogeography
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    Notes: Abstract The karyology ofCentaurea sect.Acrocentron is surveyed. 19 chromosome counts on 8 species are reported; those onC. acaulis, C. crocata, C. galianoi, C. pubescens, andC. malinvaldiana are new. The basic chromosome numbers of the section are x = 11 and x = 10. Karyological arguments have been used to show that evolution was from x = 11 to x = 10. This is supported by biogeographical data. Two main centres of diversification of sect.Acrocentron were studied from that point of view: the East and the Southwest Mediterranean region.
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    Plant systematics and evolution 179 (1992), S. 27-41 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Liliaceae ; Tulipa ; sect.Eriostemones ; subsect.Australes ; Biflores ; Saxatiles ; Morphology ; crossability ; chromosome numbers ; numerical taxonomy ; phylogeny ; biogeography
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    Notes: Abstract Evolutionary relationships and infra- and interspecific variability within the species ofTulipa sect.Eriostemones Boissier were studied. Measurements of 35 morphological characters were used for principal component and canonical variate analyses. Crossing experiments and chromosome counts were carried out. Two axes of morphological variation were encountered within the principal component plot. Variation of subsect.Biflores was traced along one axis, the species of subsect.Australes as well asSaxatiles were found along the other axis. The nomenclature of names of subsect.Biflores was considered on the basis of their geography, specific morphological characteristics and polyploidy. Conspecificity of names of all species was tested based on both morphology and crossability.
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    Plant systematics and evolution 179 (1992), S. 107-113 
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    Keywords: Angiosperms ; Plantago sect.Coronopus ; Hair morphology ; bottle-like hairs
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    Notes: Abstract The presence of bottle-like hairs has been described in four hitherto uninvestigated taxa ofPlantago sect.Coronopus sensuDietrich. This hair type is a feature characteristic of sect.Coronopus.
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    Plant systematics and evolution 180 (1992), S. 205-219 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Lemnaceae ; Lemna minor ; Phenotypic plasticity ; clonal plant ; genotypic variation ; fitness ; origin effect ; duckweed
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    Notes: Abstract Eight genotypes ofLemna minor, originating from four continents, were grown for 15 days in eight different environmental treatments. Fronds under each treatment were then transferred into each of the eight environmental conditions for 15 days. The rate of frond production (relative growth rate) and mean frond biomass were recorded for each pre- and post-transfer treatment and root length was measured for each pre-transfer treatment. For all the traits, the levels of response varied significantly between genotypes (G) and between environmental conditions (E). G × E interaction effect was significant for all traits under pre-transfer treatments and some post-transfer treatments. Both pattern and amount of plasticity were genotypically variable but the amount of variation depended on the trait. The trait representing the best estimate of fitness, growth rate, exhibited the least amount of plasticity and on average, showed the most conservative pattern of plasticity. In contrast, the trait least related to fitness, root length, was the most plastic and showed the most divergent pattern of plasticity. Under some post-transfer treatments, growth rate and mean frond biomass were affected by origin (initial treatment) effect. Pattern and amount of plasticity were also influenced by initial treatments. Since some genotypes may be more affected than others by environmental conditions, origin effect may accentuate G × E interaction and therefore, modify the pattern and amount of plasticity. Comparison between dendrograms based on genetic and phenotypic similarities suggested that there is no relationship between genetic and phenotypic divergence. This lack of relationship may be due to the fact that plasticity is not necessarily adaptive.
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    Plant systematics and evolution 180 (1992), S. 235-242 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Geraniales ; Irvingiaceae ; Desbordesia ; Irvingia ; Klainedoxa ; diptera ; Floral disc nectaries ; secretory tissue ; stomata ; pollination
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    Notes: Abstract TheIrvingiaceae generally possess large intrastaminal receptacular disc nectaries of the mesenchymatic histo-type, which receive numerous small phloematic bundles directly from the central stele. The non-glandular epidermis bears some 10 to 15 strictly localized stomata that are deeply sunken in the parenchyma. The nectar is assumed to be exposed on the disc surface. Flowers are of simple construction, lacking specialized organs to attract pollinators. A wide range of pollinators is thus expected. TheIrvingiaceae have more characters in common withSimaroubaceae thanIxonanthaceae and should therefore be retransferred as a family of their own next toSimaroubaceae.
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    Plant systematics and evolution 181 (1992), S. 1-9 
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    Keywords: Angiosperms ; Plantaginaceae ; Plantago ; Breeding system ; floral features ; male and female investment ; meiotic system
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    Notes: Abstract Investigation of the genetic system of six species ofPlantago has revealed striking differences in their breeding and meiotic systems.Plantago patagonica is an inbreeder on account of preanthesis cleistogamy, whereasP. lanceolata is an obligate outbreeder, as it is self-incompatible.Plantago drummondii, P. lagopus, P. ovata, andP. major show mixed mating but in varying proportions. In terms of their energy budgets, outbreeding species invest more in floral advertisement and male function, while inbreeders invest more in female function. The contribution of the meiotic system to genetic variability, as revealed through recombination index, is more important in the inbreeding species.
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    Plant systematics and evolution 181 (1992), S. 121-132 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Datiscaceae ; Datisca ; Chloroplast DNA ; polymerase chain reaction ; restriction-site variation ; interspecific variation ; disjunct distributions ; biogeography
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    Notes: Abstract Datisca (Datiscaceae) is a ditypic genus with an intercontinentally disjunct distribution. Chloroplast DNA restriction site data was obtained from 23 populations and four 10–20 year old herbarium specimens ofD. glomerata and three populations ofD. cannabina from throughout their geographic ranges in western North America and southwest-central Asia, respectively. InD. glomerata, plastome diversity is partitioned geographically. All populations from southern California have a common plastome, while most populations north of this region share a relatively divergent plastome (0.49% sequence divergence). Likewise, these plastomes are highly divergent (0.87% mean sequence divergence) from those found inD. cannabina. Biogeographic processes dating to the Pleistocene and Late Miocene may be responsible for these intra- and interspecific patterns of chloroplast DNA divergence.
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    Plant systematics and evolution 181 (1992), S. 171-178 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Palynology ; pollen grain wall ; cell wall strength ; functional morphology
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    Notes: Abstract 50% breaking point pressures of pollen grain walls of eleven species were determined. The breaking point pressures of most pollen grain walls are equivalent to those reported in the literature for other types of living cell walls such as bacterial spore coats, algal cell walls, mold sporophyte cells, and dicot suspension culture cells. The strongest pollen grain walls are two or three orders of magnitude stronger, however. Pollen grain walls are proportionately very thick in comparison to other types of cell walls. It is this thickness, not the construction or physical properties of the pollen grain wall, that most probably accounts for their strength.
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    Plant systematics and evolution 181 (1992), S. 227-232 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Magnoliidae ; Monimiaceae ; Daphnandra ; Hortonia ; Protogyny
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    Notes: Abstract Among theMonimiaceae only five relatively primitive genera belonging toHortonioideae andAtherospermoideae have regularly bisexual flowers. Three species of two genera (Hortonia, Daphnandra), one of each subfamily, were studied for the occurrence of dichogamy. In all of them protogyny occurs.Monimiaceae are, thus, a further example for the preponderant protogyny inMagnoliidae.
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    Plant systematics and evolution 181 (1992), S. 245-254 
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    Keywords: Angiosperms ; Brassicaceae ; Goodeniaceae ; Melastomataceae ; Pentadiplandraceae ; Resedaceae ; Salvadoraceae ; Computerized image analysis ; numerical key ; multivariate analysis ; pollen sculpture ; pollen terminology ; systematics
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    Notes: Abstract We present a key synthesizing pollen-sculpture terminology for grains having perforations or lumina of any size and spatial distribution. The key uses quantitative criteria to distinguish five non-overlapping qualitative terms (reticulate, microreticulate, foveolate, scrobiculate, and punctate). In addition, the range of quantitative variation encompassed by these qualitative terms is highlighted, including ways to express and compare that variation using computerized image analysis of SEM micrographs. Finally, a mathematical analysis combined with image-analysis measurements is used to explore the relationships between the terms outlined above and two closely related terms, tectate and semitectate.
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    Plant systematics and evolution 180 (1992), S. 243-259 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Convolvulaceae ; Systematics ; phylogeny ; chloroplast DNA ; homoplasy
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    Notes: Abstract Chloroplast DNA restriction site variation was studied in 31 New World species ofIpomoea, representing a majority of the New World sections and series within the genus. Using 14 endonucleases, a total of 124 phylogenetically informative restriction sites was detected. Dollo parsimony, Wagner parsimony, and bootstrap methods were employed to construct phylogenetic trees and evaluate confidence intervals of monophyletic groups. With a few exceptions, groups circumscribed on the basis of morphological variation are in agreement with groupings based on restriction site variation. Relationships between subgeneric groupings, however, disagree substantially with those proposed in the past. Although conflicting hypotheses for some intersectional relationships are not presently resolvable, cpDNA restriction site analyses propose the following refinements of existing classification schemes.Ipomoea ser.Setosae is divided into distantly related groups, as is sect.Pharbitis. SeriesTyrianthinae, a proposed segregate of sect.Pharbitis, is associated with sect.Calonyction and the Tricolor complex (subg.Quamoclit).Ipomoea sect.Batatas is segregated from other herbaceous groups of the heterogeneous subg.Quamoclit sensu lato and aligned as a derivative ofI. setosa, subg.Eriospermum. To test for homology of key characters weighted in traditional schemes, morphological features were studied with respect to their distribution on lineages defined by restriction site data. Characters such as setose sepals, foliose-pubescent sepals, and erect growth habit, among others, are interpreted as having multiple origins, while 3-locular ovaries, 4-locular ovaries, and long-haired seeds have evolved only once.
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    Plant systematics and evolution 183 (1992), S. 235-247 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Mimosaceae ; Acacia ; 5S DNA ; evolution ; phylogeny ; chromosomal lineages
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    Notes: Abstract The DNA sequence structure of 5S DNA units inAcacia species, including representatives from the three subgenera ofAcacia, have been determined. The data was interpreted to suggest that at least three lineages of 5S DNA sequences exist inAcacia and the proposal was made that the lineages be named5S Dna-1, 5S Dna-2, and5S Dna-3. The5S Dna-1 lineage was represented by units fromA. boliviana andA. bidwilli, the5S Dna-2 lineage by units fromA. melanoxylon, A. pycnantha, A. ulicifolia, A. boliviana, A. bidwillii, andA. albida, and the5S Dna-3 lineage by units fromA. bidwillii, A. boliviana, andA. senegal. Based on this interpretation of the sequence data, the Australian species of subg.Phyllodineae grouped together as a cluster, quite separate from the subgeneraAculeiferum andAcacia. As expected from the analyses of morphological characters, the 5S DNA units fromAcacia albida (syn.Faidherbia albida) were quite separate from the otherAcacia spp.
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  • 76
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    Keywords: Angiosperms ; Labiatae ; Teucrium marum ; Teucrium subspinosum ; Trichomes ; volatile compounds ; Flora of Italy ; Flora of the Balearic Islands
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    Notes: Abstract Micromorphology and distribution of trichomes in different plant parts ofTeucrium marum andTeucrium subspinosum from Sardinia and the Balearic Islands are described. The composition of volatile compounds in the same plants has also been studied. The occurrence in Sardinia of two differentT. marum entities is evidenced. One of them, growing in the NW. part of the island, is very similar toT. marum from Minorca.T. subspinosum from Sardinia and Majorca differ for the presence in the last one of short capitate hairs and for a higher ratio of dolichodial/teucrein. While the degree of variability of all the characters is very high, there is a good homogeneity between all the taxa, due to the presence of monoterpene cyclopentanoids not found until now in other species.
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    Plant systematics and evolution 179 (1992), S. 221-233 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Asteraceae ; Microseris ; Phylogeny ; RAPDs ; DNA fingerprinting ; isoenzymes ; dispersal ; distribution
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    Notes: Abstract The genetic relationships among 10 inbred lines representing 10 populations of the autogamous annualMicroseris elegans from throughout California has been determined using random amplified polymorphic DNAs (RAPDs). Seventeen arbitrary 10 base pair primers produced 134 amplification products; 81 of these were shared by two or more strains. The 3 genotypes from Northern California are closely related as are 3 genotypes from Middle Californian populations which are not nearest neighbors. DNA fingerprinting with the oligonucleotide (GATA)4 gave compatible results, but the comparison was limited to samples run on one gel. Isoenzyme patterns are compatible with the DNA results, but limited by the very low number of informative polymorphisms. The clustered relationship among genotypes within a species and their geographic distribution suggests very restricted genetic recombination and an origin of new populations from randomly dispersed achenes within the range of the species.
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    Plant systematics and evolution 179 (1992), S. 257-276 
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    Keywords: Angiosperms ; Geraniaceae ; Pelargonium ; Chromosome numbers ; karyotypes ; hybridization ; taxonomy
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    Notes: Abstract A study of 33 species ofPelargonium sect.Ligularia reveals four basic chromosome numbers, x = 8, 9, 10, and 11, and variation in chromosome size. From evidence of karyology and hybridization attempts, proposals are made to divide the section into smaller groups and to transfer some species to other sections.
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    Plant systematics and evolution 179 (1992), S. 235-243 
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    Keywords: Angiosperms ; Geraniales ; Limnanthaceae ; Caryophyllaceae ; Floerkea ; Limnanthes ; Floral nectaries ; secretory tissue ; stomata ; diplostemony ; pollination ; bees
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    Notes: Abstract Floral nectaries in theLimnanthaceae are established as exoscopic basal bulges of the episepalous stamens. Their nectariferous tissues include the epidermis and hypodermal parenchyma and inLimnanthes are vascularized by phloematic branches of the staminal bundles. Secretion occurs mainly through anomocytic stomata but, in addition, probably through the outer cuticularized thin walls of the epidermal cells. The flower structure is comparatively simple. The nectar is often slightly concealed. A wide range of pollinators can be expected, but bees are observed to be the dominant ones. The systematic position of the family is still obscure. Taxonomic placement near to any other geranialian families or to theCaryophyllaceae is only weakly justified.
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    Plant systematics and evolution 181 (1992), S. 33-43 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Fabaceae ; Medicago murex ; M. lesinsii ; Systematics ; evolution ; isozymes ; chromosomes
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    Notes: Abstract Chromosomal studies ofMedicago lesinsii (n = 8) and its close relativeM. murex (n = 7) have led to the competing hypotheses that the latter is derived directly from the former, or that both originated from a common ancestor. In contrast to the relatively variableM. murex, M. lesinsii proved to be almost uniform isozymically, except that most populations of Greece differed by one allele from plants of the remainder of the range. This Greek variant ofM. lesinsii was indistinguishable from one of the isozyme variants ofM. murex. The greater level of allozyme variation inM. murex was consistent with its greater ecological amplitude and competitive ability. Also, this suggests thatM. murex is unlikely to have originated directly from the less variableM. lesinsii. The data suggest that either both species originated from a common ancestor, or that the n = 8 species evolved from the n = 7 species, a mode of chromosome evolution not previously hypothesized for the genus.
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    Plant systematics and evolution 180 (1992), S. 157-180 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Caryophyllaceae ; Scleranthus annuus ; Floral morphology ; numerical analysis
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    Notes: Abstract The variation in two sets of morphological characters of the flowers of the highly inbreedingScleranthus annuus (Caryophyllaceae) was assessed using 15–20 plants from each of 20 natural populations from the southernmost region of Sweden. The stamen fertility data set consisted of 10 characters describing the degree of fertility of the ten stamens/staminoids, while the sepal/gynoecium data set comprised 10 sepal characters, together with style and stigma length. Substantial variation was found in both the degree of development and the fertility of the stamens, the degree of variability in stamen fertility being related to stamen position within the flower. Considerable variation was found in the characters of the sepal and the gynoecium. Hierarchical analyses of variance indicated that 29% of the variation in total male reproductive effort was distributed among populations, 28% among plants within populations and 43% represented within-plant variation. The corresponding averages for the characters from the sepal/gynoecium data set are 26, 38, and 35%: a greater proportion of the total variance in female reproductive characters is accounted for by among individual variation than is the case with the male reproductive characters. Significance tests of Mahalanobis’ distances derived by canonical variate analyses indicated that all populations were significantly separated using the sepal/gynoecium data set, while only 50% of the pairwise comparisons on the basis of the stamen fertility data set were significant. Cluster analysis did not reveal any aggregation of the populations. The incongruence of the two data sets and their ability to discriminate between the populations is discussed.
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  • 82
    ISSN: 1615-6110
    Keywords: Angiosperms ; Asteraceae ; Artemisia norvegica ; Populations ; chemometry ; lipids ; morphometry ; principal component analysis
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    Notes: Abstract Specimens from Scotland, S. and C. Norway were grown in the botanical garden of Bergen, Norway. Some of the Scottish specimens came from a meristem tissue culture. The specimens were compared by a principal component analysis of lipids and related compounds, and of morphological characters from leaves and flowers. The populations differed from each other, but some overlap was found in leaf characters. The results are discussed in relation to distribution and immigration history, and it is argued that the differences among the populations may have evolved in postglacial time.
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    Plant systematics and evolution 181 (1992), S. 57-76 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Poaceae ; Poa labradorica ; Poa eminens ; Dupontia fisheri ; Hybridization ; isozymes ; DNA characters ; restriction site analysis
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    Notes: Abstract Phytogeographic, ecological, morphological, anatomical, cytological, isozyme, and endonuclease restriction site evidence is presented demonstrating thatPoa labradorica is of intergeneric hybrid origin betweenDupontia fisheri subsp.psilosantha (pistillate parent) andPoa eminens (staminate parent).Poa labradorica is endemic to recently deglaciated areas of northern Quebec and Labrador which are within the overlapping range of the putative parents. Incapable of sexual reproduction,P. labradorica dominates large areas of coastal marsh through vigorous production of rhizomes. Most morphological, anatomical, cytological, isozyme, and DNA characters studied inP. labradorica showed states intermediate or additive to those of the putative parents.
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    Plant systematics and evolution 182 (1992), S. 71-106 
    ISSN: 1615-6110
    Keywords: Angiosperms ; dicotyledons ; Polygonaceae ; Polygonum ; Crystals ; extrafloral nectaries ; leaf anatomy ; secretory structures ; stomata ; subepidermal fibers ; trichomes
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    Notes: Abstract Several anatomical characters in leaves were described, and their distribution determined, for 153 species ofPolygonum, mostly from herbarium specimens. Structures surveyed were epidermal (glandular and nonglandular trichomes, nodules, specialized parenchyma, stomatal apparatus) and internal (cavities, crystals, laticifer-like cells, nodules, subepidermal fibers). Cleared leaves were supplemented by resin-embedded sections and SEM preparations of selected species. No feature defines any taxonomic section, but some features occur only within one section. Laticifer-like cells, epidermal and internal nodules, resin cups, and unique epidermal and subepidermal cavities seem to be unknown elsewhere; other features (invaginated epidermal cells; enlarged crystal cells confined to paraveinal layer) are rare among angiosperms.
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  • 85
    ISSN: 1432-1432
    Keywords: Chloroplast 4.5S rRNA ; Cytosolic and chloroplast 5S rRNAs ; 5.8S rRNA ; 18S rRNA ; Nucleotide sequences ; Phylogenetic trees ; Angiosperms ; Gymnosperms ; Monocotyledons ; Dicotyledons
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    Notes: Summary Complete or partial nucleotide sequences of five different rRNA species, coded by nuclear (18S, 5.8S, and 5S) or chloroplast genomes (5S, 4.5S) from a number of seed plants were determined. Based on the sequence data, the phylogenetic dendrograms were built by two methods, maximum parsimony and compatibility. The topologies of the trees for different rRNA species are not fully congruent, but they share some common features. It may be concluded that both gymnosperms and angiosperms are monophyletic groups. The data obtained suggest that the divergence of all the main groups of extant gymnosperms occurred after the branching off of the angiosperm lineage. As the time of divergence of at least some of these gymnosperm taxa is traceable back to the early Carboniferous, it may be concluded that the genealogical splitting of gymnosperm and angiosperm lineages occurred before this event, at least 360 million years ago, i.e., much earlier than the first angiosperm fossils were dated. Ancestral forms of angiosperms ought to be searched for among Progymnospermopsida. Genealogical relationships among gymnosperm taxa cannot be deduced unambiguously on the basis of rRNA data. The only inference may be that the taxon Gnetopsida is an artificial one, andGnetum andEphedra belong to quite different lineages of gymnosperms. As to the phylogenetic position of the two Angiospermae classes, extant monocotyledons seem to be a paraphyletic group located near the root of the angiosperm branch; it emerged at the earliest stages of angiosperm evolution. We may conclude that either monocotyledonous characters arose independently more than once in different groups of ancient Magnoliales or that monocotyledonous forms rather than dicotyledonous Magnoliales were the earliest angiosperms. Judging by the rRNA trees, Magnoliales are the most ancient group among dicotyledons. The most ancient lineage among monocotyledons leads to modern Liliaceae.
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    Pharmacy world & science 13 (1991), S. 70-73 
    ISSN: 1573-739X
    Keywords: Algae ; Angiosperms ; Arthropods ; Bacteria ; Fungi ; Lichens ; Marine animals ; Quinones, naturally occurring
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    Topics: Chemistry and Pharmacology
    Notes: Abstract Angiosperms, fungi (including lichens), and bacteria are the main sources of natural quinones. Small numbers are present in algae, ferns, conifers, sponges, echinoderms, other marine animals, and arthropods. In angiosperms quinones have some chemotaxonomic value at the genus and family level but more surveys are required.
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    Plant systematics and evolution 174 (1991), S. 1-4 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Zingiberaceae ; Globba ; Taxonomy ; Flora of Malesia and Malaysia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Based on personal collections ofGlobba unifolia Ridl. andG. unifolia var.sessiliflora Holtt., the latter is recognized as a distinct species. As the nameG. sessiliflora is already occupied, the nomen novumG. corneri is proposed in honour of Prof. DrE. J. H. Corner, who was the first collector of the plant.
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    Plant systematics and evolution 174 (1991), S. 17-35 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Solanaceae ; Nierembergia ; Tapinotaspis ; Centris ; Lanthanomelissa ; Paratetrapedia ; Pollination biology ; oil-flowers
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    Notes: 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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    Plant systematics and evolution 174 (1991), S. 115-123 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Orchidaceae ; Anacamptis pyramidalis ; A. urvilleana ; Polyploidy ; isolation mechanisms ; speciation ; Flora of the Mediterranean ; Malta
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    Notes: 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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    Plant systematics and evolution 174 (1991), S. 5-16 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Caryophyllaceae ; Scleranthus ; Floral morphology ; within-population crosses
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    Topics: Biology
    Notes: Abstract I used a discontinuous population ofScleranthus annuus (Caryophyllaceae) to study the effect of crossing distances on flower morphology of the progeny. Four types of progeny were produced by artificial selfing, crossing with pollen-donors from the same patch in the population, crossing with pollen from donors from other patches in the population and inter-population crosses. The size of gynoecium parts and 12 sepal characters in this petal-lacking species were significantly influenced by the type of cross and the patch in the population from where the seed-parents originated. All comparisons of progeny types except selfed vs progeny produced by within-patch crosses were significantly separated from each other, while all four seed-parent patches used were significantly separated in a multidimensional space.
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  • 91
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    Plant systematics and evolution 175 (1991), S. 11-21 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Leguminosae ; Cicer ; Allozymes ; isozyme gene duplication ; phylogenetic relations ; polymorphism
    Source: Springer Online Journal Archives 1860-2000
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    Notes: 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.
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  • 92
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    Plant systematics and evolution 175 (1991), S. 87-92 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Compositae ; Eupatorieae ; Mikania ; Mikania swartziana complex ; Dioecy ; Flora of the Greater Antilles
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    Notes: 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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  • 93
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    Keywords: Angiosperms ; Salicaceae ; Populus tremuloides ; Alpine community ecology ; clonal organisms ; DNA fingerprinting ; population genetics ; rflp analysis
    Source: Springer Online Journal Archives 1860-2000
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    Notes: 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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  • 94
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    Plant systematics and evolution 175 (1991), S. 161-223 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Orchidaceae ; Coryciinae ; Ceratandra ; Evota ; Evotella ; Ommatodium ; Pterygodium ; Anochilus ; Corycium ; Morphology ; phylogeny ; cladistics ; phytogeography ; speciation ; classification ; Flora of southern Africa
    Source: Springer Online Journal Archives 1860-2000
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    Notes: 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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  • 95
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    Plant systematics and evolution 176 (1991), S. 53-61 
    ISSN: 1615-6110
    Keywords: Angiosperms ; monocotyledons ; Orchidaceae ; Cephalanthera ; Allozymes ; electrophoresis ; genetic variation ; breeding type
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: 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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  • 96
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    Plant systematics and evolution 176 (1991), S. 145-177 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Asteraceae ; Plucheeae ; Cladistics ; phylogeny ; taxonomy
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    Notes: 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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  • 97
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    Plant systematics and evolution 175 (1991), S. 1-10 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Iridaceae ; Tigridieae ; Leaf anatomy ; systematics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: 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.
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  • 98
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    Plant systematics and evolution 177 (1991), S. 53-69 
    ISSN: 1615-6110
    Keywords: 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
    Source: Springer Online Journal Archives 1860-2000
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    Notes: 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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  • 99
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    Plant systematics and evolution 176 (1991), S. 63-74 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Bromeliaceae ; Tillandsia pallidoflavens ; Microsporogenesis ; organelle ultrastructure ; plastids ; periodic acid-thiocarbohydrazine-silver proteinate staining
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: 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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  • 100
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    Plant systematics and evolution 176 (1991), S. 125-131 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Polygonaceae Aconogonon campanulatum ; Heterostyly ; floral dimorphism ; pollination ; dioecy ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: 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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