Low isozyme diversity in Nordic and central European populations of Vicia pisiformis and V. dumetorum (Fabaceae)

Vicia pisiformis and V. dumetorum are closely related perennial species occurring in small, disjunct populations throughout Europe. In Sweden, they are classified as "vulnerable" and "care-demanding", respectively. They possess low variation in RAPD (Random Amplified Polymorphic DNA) markers but relatively high morphological variation. We estimated the amount and distribution of isozyme diversity within and among marginal (Sweden, Norway) and central (Czech Republic) populations. Vicia dumetorum was monomorphic for all 14 isozyme loci in the 22 populations investigated, whereas V. pisiformis had 2.94 % polymorphic loci and a mean of 1.02 alleles per loci. The differentiation (F_sr) of populations of V pisiformis were 0.848, but no clear geographical pattern was found. Preliminary results from artificial pollination experiments suggests self-compatibility in V. dumetorum . The low overall polymorphism in Swedish and Czech localities in both species is explained in terms of common postglacial colonization events, recent anthropogenic activity, selfing and clonal reproduction. Finally, the implications of the data for conservation genetics is discussed.     

Cladistic and phenetic analysis of relationships in Vicia subgenus Vicia (Fabaceae) by morphology and isozymes

 Variation of 80 multistate morphological characters and isozymes encoded by 13 loci among 23 vetch species of the type subgenus of the genus Vicia in comparison with V. dumetorum, V. pisiformis and V. sylvatica of the subgenus Cracca is described and analyzed with cladistic parsimony and phenetic neighbour-joining methods by using two different ways of coding. Morphological analyses showed the subgenus Vicia monophyletic and revealed subgroups in a general agreement with traditionally recognized sections, except showing V. faba nested within section Narbonensis and ambiguity in the position of V. lathyroides and V. bithynica. Parsimony analysis of orthozymes as presence/absence characters revealed in the subgenus two basic monophyletic clades: 1) V. faba and three species of the section Peregrinae, V. michauxii, V. aintabensis and V. peregrina, in one subclade linked with species of the Narbonensis and Hyperchusa sections together with V. pisiformis of subgenus Cracca in a second subclade; 2) species belonging to sections Vicia, Sepium, Pseudolathyrus and Lathyroides together with V. sylvatica of the subgenus Cracca. Neighbour-joining analysis of orthozymes revealed the same two basic groups, differing only in the relative position of some species in subclusters. Both isozyme analyses showed paraphyly of the subgenera Vicia and Cracca. Parsimony analysis of orthozymes as character states of isozymes yielded a largely unresolved strict consensus cladogram of 209 most parsimonious trees, and reweighting of characters failed to produce a stable tree. Phylogenetic congruence and discordance among morphological and isozyme analyses, coding ways, homoplasy and weighting of characters are discussed. Received November 20, 2001 Accepted January 31, 2002     

Unravelling the phylogeny of tetraploid Vicia amoena (Fabaceae) and its diploid relatives using chromosomal landmarks

The chromosomal sites of 5S and 45S rDNA genes were revealed by fluorescence in situ hybridisation, and used as landmarks to resolve the ambiguous taxonomic status of the tetraploid Vicia amoena var. amoena (Fabaceae). Comparisons of the number and location of rDNA loci in V. amoena var. sericea, V. pseudorobus, V. dumetorum, V. pisiformis and V. cracca confirmed that V. amoena var sericea, or a closely related diploid, was a likely progenitor of the tetraploid. However, the tetraploid contains chromosomes bearing rDNA loci which are probably derived from another species, such as V. pseudorobus, suggesting that it is an allotetraploid and the product of an interspecific hybridisation event. This was corroborated by fluorescence in situ hybridisation with genomic DNA from V. amoena var sericea, which not only showed that the tetraploid contains more than one chromosome set, but also that its constituent sets have undergone considerable reorganisation.     

Infrageneric variation of the low molecular weight carbohydrate composition of the seeds of the genusVicia (Leguminosae)

The low molecular weight carbohydrate compositions of the seeds of 29 species ofVicia, namelyV. amoena, V. amurensis, V. bifolia, V. dumetorum, V. fauriei, V. japonica, V. nipponica, V. pisiformis, V. pseudo-orobus, V. sylvatica, V. unijuga, V. venosa, V. cassubica, V. orobus, V. cracca agg.,V. hirsuta, V. villosa agg.,V. tetrasperma,V. oroboides, V. sepium, V. cuspidata, V. grandiflora, V. lathyloides, V. sativa agg.,V. bithynica, V. faba, V. narbonensis, V. hybrida andV. lutea were determined by gas liquid chromatography. The carbohydrate compositions were found to be species-specific. Principal component analysis of the carbohydrate composition data showed that these species can be divided into three groups. Although, as far as the examined species were concerned, these groups were not correlated with the known subgenera, significant correlation between the groups and the known sections was detected in the subgenusVicia. The carbohydrate composition character would be important to clarify the relationships among closely related taxa of the genusVicia.     

Isozyme evidence on the specific distinctness and phylogenetic position of <Emphasis Type="Italic">Vicia incisa</Emphasis> (Fabaceae)

Vicia incisa is a taxonomically controversial species that has been also treated as a subspecies of V. sativa because of a great morphological similarity. The phylogenetic position of V. incisa is uncertain because various DNA markers have provided contradictory results. Isozymes of V. incisa encoded by 15 loci and resolved with the use of polyacrylamide gel electrophoresis (PAGE) are described and compared with those of seven related species belonging to sections Vicia, Sepium, Lathyroides and Pseudolathyrus in order to get new evidence about its taxonomic rank and phylogenetic position. Phylogenetic relationships are analyzed with maximum parsimony and neighbour joining methods. Vicia incisa is shown to differ from all three subspecies of V. sativa including, sativa, cordata and nigra, by alternate variants of ten isozymes out of 15 analysed. Instead, V. incisa has much more similarity to V. grandiflora and V. sepium by sharing eight isozyme variants which differ from the subspecies of V. sativa. The most parsimony and neighbour joining analyses of the isozyme variation placed V. incisa as basally linked to the V. grandiflora and V. sepium species couple in the clade of section Sepium (= sect. Atossa), while the subspecies of V. sativa together with V. lathyroides formed a separate clade of section Vicia. The isozyme data provide further support to the species status of V. incisa.     

Genomes,multiple origins,and lineage recombination in the Glycine tomentella (Leguminosae) polyploid complex: histone H3-D gene sequences

Relationships among the various diploid and polyploid taxa that comprise Glycine tomentella have been hypothesized from crossing studies, isozyme data, and repeat length variation for the 5S nuclear ribosomal gene loci. However, several key questions have persisted, and detailed phylogenetic evidence from homoeologous nuclear genes has been lacking. The histone H3-D locus is single copy in diploid Glycine species and has been used to elucidate relationships among diploid races of G. tomentella, providing a framework for testing genome origins in the polyploid complex. For all six G. tomentella polyploid races (T1-T6), alleles at two homoeologous histone H3-D loci were isolated and analyzed phylogenetically with alleles from diploid Glycine species, permitting the identification of all of the homoeologous genomes of the complex. Allele networks were constructed to subdivide groups of homoeologous alleles further, and two-locus genotypes were constructed using these allele classes. Results suggest that some races have more than one origin and that interfertility within races has led to lineage recombination. Most alleles in polyploids are identical or closely related to alleles in diploids, suggesting recency of polyploid origins and spread beyond Australia. These features parallel the other component of the Glycine subgenus Glycine polyploid complex, G. tabacina, one of whose races shares a diploid genome with a G. tomentella polyploid race.     

Isoenzyme diversity and phylogenetic relationships among the American beans of the genus Vigna Savi (Fabaceae)

Electrophoretic variation of 13 isoenzyme systems encoded by 25 gene loci has been studied among the 12 American bean species of the genus Vigna, subgenera Sigmoidotropis and Lasiospron, in comparison with the two pantropical species Vigna luteola and V. vexillata of the subgenera Vigna and Plectrotropis, respectively. Of the 202 electromorphs (putative allozymes) discovered, 106 were phylogenetically informative, i.e. shared by at least two taxa, and 96 were taxon-specific. Parsimony, neighbour-joining and UPGMA analyses of the isozyme data as unordered presence–absence characters revealed the division of the American Vigna species into six clades which mostly correspond to the grouping of species into subgenera and sections in the traditional morphology-based systems, except in the placement of species V. gentryi and V. caracalla. The type species of the section Caracallae, V. caracalla, appears on the cladogram as basally paraphyletic in the subgenus Sigmoidotropis, but apart from the V. linearis group of the same section which forms a separate subclade. Vigna gentryi is not linked to other species of the section Sigmoidotropis, but appears in a distant subclade as a sister species to V. adenantha s. l. of the section Leptospron. The subgenus Lasiospron is sister to the pantropical V. vexillata of the African subgenus Plectrotropis.     

Convergence and divergence between morphology and karyology in related species of the genus Vicia]

Karyological polymorphism is generally the rule in related species of genus Vicia, as has been frequently shown in many entities of its comprehensive species; therefore a correspondence of phenotypic and karyotypic characters is rather rare. Two cases are described here, in which both external morphological and internal karyological features, are correlated. These data have been obtained through biometric and karyotypic studies, carried out both on the perennials V. onobrychioides and V. altissima, and on the annuals V. villosa ssp. varia and V. benghalensis. In both perennials the chromosomes were rather long, the nucleolar constriction was on the longest couple of chromosomes, and even the satellite was of the same type; in both annuals the chromosomes were short, the nucleolar constriction was on the shortest couple of chromosomes, and the satellite was large in comparison to the arm to which it was connected. These similarities of the karyotypes are important because they may make easier a possible experimental cross-breed of the abovementioned entities.     

Phylogenetic relationships within Plantago (Plantaginaceae): evidence from nuclear ribosomal ITS and plastid trnL-F sequence data

A molecular phylogenetic study of Plantago L. (Plantaginaceae) analysed nucleotide variation in the internal transcribed spacers (ITS) of nuclear ribosomal and plastid trnL-F regions. Included are 57 Plantago species, with two Aragoa species as the ingroup and three Veronica species as the outgroup. Phylogenetic analysis using maximum parsimony identified five major clades, corresponding to the taxonomic groups Plantago subgenera Plantago, Coronopus, Psyllium, Littorella and Bougueria . Aragoa is sister to genus Plantago . Plantago subgenus Littorella is sister to the other subgenera of Plantago . The results are in general correlated with a morphological phylogenetic study and iridoid glucoside patterns, but Plantago subgenus Albicans is paraphyletic and should be included in Plantago subgenus Psyllium sensu lato to obtain a monophyletic clade with six sections. Plantago section Hymenopsyllium is more closely related to section Gnaphaloides than to section Albicans . Plantago subgenus Bougueria is sister to subgenus Psyllium s.l. section Coronopus in Plantago subgenus Coronopus is subdivided in two series. Only some of the sections can be resolved into series. DNA variation within genus Plantago is high, a result that would not have been predicted on the basis of morphology, which is relatively stereotyped. If we calibrate a molecular clock based on the divergence of P. stauntoni , endemic to New Amsterdam in the southern Indian Ocean, we calculate the time of the split between Plantago and Aragoa to be 7.1 million years ago, which is congruent with the fossil record.  © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 139 , 323–338.     

Phylogenetic relationships in family Magnoliaceae inferred from ndhF sequences

The ndhF sequences of 99 taxa, representing all sections in extant Magnoliaceae, were analyzed to address phylogenetic questions in the family. Magnolia macrophylla and M. dealbata, North American species of Magnolia section Rytidospermum, are placed at the base in the subfamily Magnolioideae although its supporting value is low. In the remaining taxa, several distinctive lineages are recognized: (1) Magnolia, the biggest genus in the family, is not monophyletic; (2) Michelia, including section Maingola of Magnolia subgenus Magnolia, is closely related with Elmerrillia and sections Alcimandra and Aromadendron of Magnolia subgenus Magnolia; (3) the associates of Michelia are grouped with Magnolia subgenus Yulania and section Gynopodium of Magnolia subgenus Magnolia; (4) Pachylarnax forms a clade with sections Manglietiastrum and Gynopodium of Magnolia; (5) a well-supported Manglietia clade is recognized; (6) Caribbean species of section Theorhodon of Magnolia subgenus Magnolia, which are section Splendentes sensu Vázquez-Garcia, are closely allied with New World members of Magnolia subgenus Talauma; and (7) section Rytidospermum of Magnolia subgenus Magnolia and subgenus Talauma are polyphyletic. The separated clades in the molecular tree are considerably different from traditional taxonomic dispositions in the family. The molecular data strongly suggest that a taxonomic realignment of infrafamilial delimitations and compositions should be considered.