Species relationships within Diplotaxis (Brassicaceae) and the phylogenetic origin of D . muralis (original) (raw)
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Molecular phylogeny indicates polyphyly in Raphanus L. (Brassicaceae)
Edinburgh Journal of Botany, 2014
We evaluated the systematic relationship of the two sections of Raphanus (Brassicaceae) on the basis of morphological and ITS data. We obtained strong support that Raphanus is a polyphyletic group embedded in the Oleracea lineage of the tribe Brassiceae. Section Raphanis, which includes Raphanus raphanistrum, R. pugioniformis and R. sativus, is a strongly supported monophyletic lineage. Section Hesperidopsis is embedded in a different lineage together with Brassica deflexa and B. aucheri. We propose to reinstate the genus Quidproquo in place of Raphanus sect. Hesperidopsis as reflected by both morphological data and ITS phylogeny.
Plant Systematics and Evolution, 2004
Genetic variation within two closely related Diplotaxis species was studied as indicated by isozymes and RAPDs. These species differ in their mating systems, their life forms, and in their evolutionary history, but both are successful colonisers. The diploid perennial D. tenuifolia is an outbreeder, the allotetraploid annual to biennial D. muralis is predominantly selfing. D. muralis was nearly devoid of genetic variation due to a young phylogenetic age and/or population history. Estimations of genetic variation within D. tenuifolia and F-statistics indicated random mating at the species and population level and confirms obligate outbreeding. However, influence of genetic drift relative to gene flow was high and mirrors colonisation processes as indicated by considerable heterogeneity across populations and the lack of correlation between population divergence and geographic distance.
Chromosomal Phylogeny and Karyotype Evolution in x=7 Crucifer Species (Brassicaceae)
THE PLANT CELL ONLINE, 2008
Karyotype evolution in species with identical chromosome number but belonging to distinct phylogenetic clades is a longstanding question of plant biology, intractable by conventional cytogenetic techniques. Here, we apply comparative chromosome painting (CCP) to reconstruct karyotype evolution in eight species with x=7 (2n=14, 28) chromosomes from six Brassicaceae tribes. CCP data allowed us to reconstruct an ancestral Proto-Calepineae Karyotype (PCK; n=7) shared by all x=7 species analyzed. The PCK has been preserved in the tribes Calepineae, Conringieae, and Noccaeeae, whereas karyotypes of Eutremeae, Isatideae, and Sisymbrieae are characterized by an additional translocation. The inferred chromosomal phylogeny provided compelling evidence for a monophyletic origin of the x=7 tribes. Moreover, chromosomal data along with previously published gene phylogenies strongly suggest the PCK to represent an ancestral karyotype of the tribe Brassiceae prior to its tribe-specific whole-genome triplication. As the PCK shares five chromosomes and conserved associations of genomic blocks with the putative Ancestral Crucifer Karyotype (n=8) of crucifer Lineage I, we propose that both karyotypes descended from a common ancestor. A tentative origin of the PCK via chromosome number reduction from n=8 to n=7 is outlined. Comparative chromosome maps of two important model species, Noccaea caerulescens and Thellungiella halophila, and complete karyotypes of two purported autotetraploid Calepineae species (2n=4x=28) were reconstructed by CCP.
Plant Systematics and Evolution, 1990
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.39) and its subunits (large subunits = LSU, small subunits = SSU) were isolated from three Capsella spp. by gel electrophoresis and polypeptide composition was analyzed by isoelectric focusing (IEF) in the presence of 8 M urea. The described techniques are recommended for large scale systematic studies. Multiple IEF banding patterns of the SSU are probably the outcome of a heterogenous multigene family. The two diploid species C. rubella and C. grandiflora show an identical IEF pattern and could be differentiated from the putative allotetraploid C. bursa-pastoris only by the SSU banding pattern. Uniqueness of some SSU bands in the tetraploid and in the two diploid species, respectively, may indicate an ancient alloploid origin of tetraploid C. bursa-pastoris followed by events leading to divergences in the genomes of the allotetraploid and its presumed diploid progenitors after the hybridization event (SSU gene elimination, acquisition of new SSU genes). 206 K. MUMMENHOFF & H. HURKA: prior to IEF. The origin of multiple IEF patterns of LSU and SSU is discussed in detail. The genus Capsella MED. is recognized here as comprising three species (HURKA 1983): The two diploid species (2n= 2x = 16) C. rubella REUTER from the Mediterranean region, C. grandiflora (FAucHI~ & CHAUB.) Bolss. from western Greece and northern Italy and the tetraploid (2 n= 4x = 32) C. bursa-pastoris (L.) MED. The latter is among the most common plants on earth and has a worldwide distribution except for the hot and wet tropics. The duplicate genomic state may contribute to its colonizing ability (HURKA & al. 1989). Little is known about interrelationships of the three taxa. A matter of special interest is the evolution of the tetraploid the C. bursa-pastoris. Recently it was suggested by HURKA & al. (1989) that this species may be of an ancient alloploid origin. In this study IEF patterns of Rubisco have been used to gain further information on the evolution of the tetraploid C. bursa-pastoris and to provide new insights upon relationships within the genus. Rubisco data presented in this paper seem to support an ancient alloploid origin of C. bursa-pastoris. Material and methods A. Plant material. Provenances of the three Capsella spp. under study are listed below. Seeds were collected from individual plants in the field and progeny was raised under greenhouse conditions. Voucher specimens are kept at the herbarium of the University of Osnabrfick.
Seed image analysis and taxonomy of Diplotaxis DC. (Brassicaceae, Brassiceae)
2012
The genus Diplotaxis, comprising 32 or 34 species, plus several additional infraspecific taxa, displays a considerable degree of heterogeneity in the morphology, molecular markers, chromosome numbers and geographical amplitude of the species. The taxonomic relationships within the genus Diplotaxis were investigated by phenetic characterisation of germplasm belonging to 27 taxa of the genus, because there is an increasing interest in Diplotaxis, since some of its species (D. tenuifolia, D. muralis) are gathered or cultivated for human consumption, whereas others are frequent arable weeds (D. erucoides) in many European vineyards. Using a computer-aided vision system, 33 morpho-colorimetric features of seeds were electronically measured. The data were used to implement a statistical classifier, which is able to discriminate the taxa within the genus Diplotaxis, in order to compare the resulting species grouping with the current infrageneric systematics of this genus. Despite the high heterogeneity of the samples, due to the great intra-population variability, the stepwise Linear Discriminant Analysis method, applied to distinguish the groups, was able to reach over 80% correct identification. The results obtained allowed us to confirm the current taxonomic position of most taxa and suggested the taxonomic position of others for reconsideration.
Annals of Botany, 2004
d Background and Aims Diploid representatives from the related polyploid complexes of Cardamine amara, C. pratensis and C. raphanifolia (Brassicaceae), were studied to elucidate phylogenetic relationships among the complexes and among the individual taxa included. d Methods Two independent molecular data sets were used: nucleotide sequences from the internal transcribed spacers (ITS) of nrDNA, and ampli®ed fragment length polymorphism (AFLP) markers. Seventeen diploid taxa from the studied groups were sampled. d Key Results Both ITS and AFLP analyses provided congruent results in inferred relationships, and revealed two main lineages. While the C. amara group, consisting of C. wiedemanniana and four subspecies of C. amara, was resolved as a well-supported monophyletic group, taxa from the C. pratensis and C. tenera groups (the latter representing diploid taxa of the complex of C. raphanifolia) all appeared together in a single clade/cluster with no support for the recognition of either of the groups. Intra-individual polymorphisms and patterns of nucleotide variation in the ITS region in C. uliginosa and C. tenera, together with the distribution of AFLP bands, indicate ancient hybridization and introgression among these Caucasian diploids. d Conclusions The lack of supported hierarchical structure suggests that extensive reticulate evolution between these groups, even at the diploid level, has occurred (although an alternative explanation, namely ancestral polymorphism in ITS data, cannot be completely excluded). Several implications for the investigation of the polyploid complexes of concern are drawn. When tracing origins of polyploid taxa, a much more complex scenario should be expected, taking into account all relatives as potential parents, irrespective of the group in which they are classi®ed.
Plant Systematics and Evolution, 2010
Sequence data from the nuclear encoded ribosomal internal transcribed spacer (ITS) region were used to determine monophyly of tribes, tribal limits, and tribal relationships of 96 so far unassigned or tentatively assigned genera (represented by 101 taxa/accessions) within the Brassicaceae. Maximum-parsimony and maximumlikelihood analyses of 185 ITS Brassicaceae sequences, which also included representatives of each of the 34 currently recognized tribes, supported the separate phylogenetic distinctness of these tribes and permitted the tribal assignment of all but 12 of the unassigned genera into tribal clades.
Plant Systematics and Evolution, 2015
Database of published chromosome numbers and ploidy-level estimates of the tribe Alysseae is presented, together with the revised generic concept and the list of accepted names, to reflect the most recent taxonomic and phylogenetic studies in Alysseae. It is available on-line at www.alysseae.sav.sk. The tribe encompasses 24 genera and 277 species. Chromosome numbers and/or ploidy levels are known for 171 out of 297 recognized taxa. Of these, 95 (55.6 %) taxa are diploids, 43 (25.1 %) are polyploids, and 33 (19.3 %) involve both diploids and polyploids. The most common base chromosome number in the tribe is x = 8 and less frequent is x = 7. The highest variation in base chromosome numbers (x = 7, 8, 11, 15) is found in the genus Hormathophylla. A key to all genera and descriptions of the two new genera Cuprella and Resetnikia are presented. Many new nomenclatural combinations, mainly in the re-established Odontarrhena (77), are proposed.