Molecular systematics of some bifurcate hairy sections in Astragalus L. (Fabaceae) as inferred from nuclear and chloroplast DNA sequences (original) (raw)
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Bangladesh Journal of Plant Taxonomy, 2016
In this study, 38 species belonging to some bifurcate hairy sections of Astragalus L. were analyzed phylogenetically, using nuclear and plastid DNA sequences. Based on our results, Astragalus sect. Dissitiflori DC. with the inclusion of the members of section Erioceras Bunge, formed a monophyletic group. The members of sect. Ornithopodium Bunge and Onobrychoidei DC. were located together within a highly supported monophyletic clade, apart from other sections studied, on the basis of the present molecular data.The positioning of the enigmatic, recently established species, A. juladakensis Maassoumi, within the sect. Dissitiflori was verified. In addition, our results showed that A. pravitzii Podl., which had been already transferred to sect. Ornithopodium, belongs to the section Dissitiflori.
Plant Systematics and Evolution, 2003
Comparative sequencing of internal transcribed spacers (ITS) and 5.8S gene of nuclear ribosomal DNA was carried out to examine phylogenetic relationships among subgenera and sections of Old World Astragalus as well as the recent segregate genera Barnebyella and Ophiocarpus. For a subset of these taxa (43 accessions), the nrDNA ITS data were supplemented by sequences from the chloroplast ndhF gene. Phylogenetic trees resulting from separate analyses of the nrDNA ITS and ndhF sequences were in conflict mainly on the position and relationships of Ophiocarpus aitchisonii, Astragalus hemsleyi, A. grammocalyx, A. coelicolor, A. capito, A. epiglottis and A. annularis. Excluding these taxa, phylogenetic analysis of a combined nrDNA ITS-ndhF data matrix was also conducted, so that in the resulting tree, most clades were more resolved and better statistically supported than those were in the separate analyses. Our results indicate that the monotypic segregate genera Barnebyella (= A. migpo), Ophiocarpus (= A. ophiocarpus) and morphologically isolated annual species A. dipelta (= Didymopelta turkestanica), A. schmalhausenii (= Sewerzowia turkestanica) and A. vicarius (= S. vicaria) are clearly nested within Astragalus. Our results confirm earlier studies that shows A. vogelii is allied with the genera Colutea and Oxytropis rather than with any Astragalus species. It is therefore excluded from Astragalus and elevated to the new generic rank and named as Podlechiella Maassoumi and Kazempour Osaloo. None of the eight traditionally recognized Astragalus subgenera Epiglottis, Trimeniaeus, Phaca, Hypoglottis, Calycophysa, Tragacantha, Cercidothrix and Calycocystis are monophyletic. Similarly, the monophyly of Podlech's new subgenera Trimeniaeus, Astragalus and Cercidothrix is not supported. Among the many speciesrich sections analyzed here, only Cenanthrum, Chronopus, Laxiflori, Lotidium, Incani and Amodendron are monophyletic.
Phylogenetic relationships among 30 species of sect. Onobrychoidei and some related sections are investigated using nrDNA ITS and morphological data. Based on Maximum Parsimony and Bayesian analyses the morphological characters are useful at the sectional level but not at lower taxonomic ranks. Astragalus sect. Onobrychoidei at the current status is not monophyletic. Some members of the section are well intermixed with members of related sections. Another species of the section, A. oligoflorus, is well allied with species of the sect Erioceras at the base of the resulting phylogenetic trees. Analyses confirmed that debatable species A. goktschaicus and A. scapiger are belonging to the sect. Onobrychoidei. A. huthianus (of sect. Craccina) was also placed within sect. Onobrychoidei and it should be classified as a member of latter section.
Morphological cladistic analysis of some bifurcate hairy sections of Astragalus (Fabaceae) in Iran
Turkish Journal of Botany
Th e phylogenetic relationships among some bifurcate hairy sections of Astragalus L. were reconstructed using 38 vegetative and reproductive morphological characters. A data matrix comprising 36 ingroups and 2 outgroups was analysed using the maximum parsimony method. Th e present results revealed that sections Onobrychoidei DC. and Ornithopodium Bunge are interrelated taxa and form a single monophyletic group. Th e current status of section Dissitifl ori DC. is a nonmonophyletic group. Its members form several subclades and unresolved branches across the tree. Sections Erioceras Bunge and Cytisodes Bunge as well as Corethrum Bunge are sister taxa and form weakly to highly supported monophyletic groups, respectively. Astragalus pravitzii Podlech, which was recently transferred to section Ornithopodium from section Dissitifl ori, has no affi nity with that section.
Plant Systematics and Evolution, 2011
We conducted phylogenetic analyses of the sect. Caprini and its closely related sections within Astragalus. Analyses of a combined dataset including nrDNA ETS and three cpDNA markers using maximum parsimony and Bayesian inference from 44 species of sect. Caprini and its allied taxa yielded congruent relationships among several major lineages. These results largely disagree with previously recognized taxonomic groups, most notably in the following ways: (1) subsects. Caprini and Purpurascentes of sect. Caprini are not natural groups; (2) sects. Alopecuroidei and Laxiflori are nested within sect. Astragalus; and (3) subsect. Chronopus constitutes a separate phylogenetic lineage. Representatives of sects. Astragalus, Alopecuroidei, and Laxiflori share a common ancestor with that of sect. Caprini. Our studies indicate that Astragalus annularis is an outlier species for the genus Astragalus and sect. Caraganella is the first-diverging clade within the genus Astragalus. Results of these analyses are supported by morphology and suggest the need for new taxonomic delimitations, which are forthcoming. Key morphological characters were mapped onto the phylogenetic tree and discussed.
Phylogeny of Astragalus Sect. Alopecuroidei Based on the Combined Nrdna Its and Morphology
Rostaniha, 2013
A phylogenetic analysis of Astragalus sect. Alopecuroidei based on nrDNA ITS as well as morphological character data is presented. A total of fifty informative morphological characters were analyzed to reconstruct phylogenetic relationships for 23 taxa of the sect. Alopecuroidei and two species of sect. Laxiflori plus A. sieversianus and A. caryolobus as outgroups. The present analysis revealed that the Alopecuroidei with the inclusion of sect. Laxiflori is monophyletic. This is well consistent with the previous works even with the small taxon sampling. Astragalus alopecias was positioned at the base of the resulting trees. The present study indicates that all six/four informal species groups, except the Kirrindicus (=Obtusifolius) group and Turbinatus group, recognized within the Alopecuroidei were not monophyletic. nrDNA and morphology-based phylogenies were conflicting regarding the position of A. saetiger, A. turbinatus and A. neoassadianus.
Plant Syst Evol DOI 10.1007/s00606-013-0868-9
Comparative molecular phylogenetic study using nrDNA internal transcribed spacer region (ITS) sequences was carried out on species from three Astragalus L. (Fabaceae) sections from Turkey (Old World species) and the New World. A total of 56 taxa (179 accessions) including 30 species from Incani DC., 15 species from Hypoglottidei DC. and 11 species from Dissitiflori DC. section were used in the current study. The total length of the ITS region was 642 bp with 56 (8.7 %) parsimonyinformative and 9 insertion\deletion sites. The constructed phylogenetic tree suggested that the section Incani had the most conserved ITS region among the studied Astragalus sections, evolutionarily separated from other sections and monophyletic. Also, DNA sequences of several New World (Neo-) Astragalus species analyzed comparatively with those from the current study indicated that New World aneuploid species of Astragalus clearly formed a monophyletic group separated from the species of the Old World.
Nordic Journal of Botany, 2009
This study reports maximum parsimony and Bayesian phylogenetic analyses of selected Old World Astragalus using two chloroplast fragments including trnL-F and ndhF and the nuclear ribosomal internal transcribed spacer (nrDNA ITS). A total of 52 taxa including 34 euploid Old World and New World Astragalus, one aneuploid species from the Neo-Astragalus clade as a representative and 14 other Astragalean taxa, plus Cheseneya astragalina and two species of Caragana as outgroups were analyzed for both trnL-F and nrDNA ITS regions. ndhF was analyzed in 30 taxa and the same number for the combination of these three datasets were examined. In general, the trnL-F dataset and the ndhF and nrDNA ITS datasets generated more or less the same clades within Astragalus. However, in the trnL-F and ndhF phylogenies, Astragalus species are not gathered in a single clade, the so-called Astragalus s.s., as indicated by the nrDNA ITS tree. Visual inspection of these three phylogenies revealed that they were inconsistent regarding the position and relationships of Astragalus hemsleyi, A. ophiocarpus, A. annularisÁA. epiglottis/Astragalus pelecinus, A. echinatus and A. arizonicus. Incongruence length difference test suggested that the trnL-F, ndhF and nrDNA ITS datasets were incongruent. In spite of this, phylogenetic analyses of the combined datasets as one unit or as three partitions generated trees that were topologically similar as a mix of the cpDNA and the nrDNA ITS trees. However, the combined dataset provided more resolved and statistically supported clades. The recently described A. memoriosus appeared closely related to A. stocksii (both from sect. Caraganella) based on both trnL-F and nrDNA ITS sequences.
Perspectives in taxonomy and phylogeny of the genus Astragalus (Fabaceae): a review. Prog Biol Sci 3
2012
The genus Astragalus L. (Fabaceae) is reviewed from both phyloenetic and taxonomic points of view. As the largest genus of flowering plants it has attracted many researchers, but much work remains to be done. A short taxonomic history with special focus on infrageneric classification of the genus, a list of phylogenetic studies including the applied markers and sampling strategies as well as a short discussion on evolution of morphological characters are presented.