PHYLOGENY OF ASTRAGALUS SECTION DISSITIFLORI BASED ON nrDNA ITS AND MORPHOLOGICAL DATA IN IRAN

Twenty four species belonging mainly to Astragalus L. section Dissitiflori DC. and some related sections were analyzed using maximum parsimony and Bayesian methods on the basis of nrDNA ITS sequences and morphological data. Trees resulted from two datasets were in agreement on their overall topologies. Based on our results, members of the section Dissitiflori didn't constitute a monophyletic group. However, the section with inclusion of the species from the other related ones, considered to be a monophyletic group. Since A. virgatus as the lectotype of the section Dissitiflori was not included in the present study; it is difficult to evaluate the monophyly of the section and to delimit it explicitly. Astragalus juladakensis, shows a basal position in both nrDNA ITS and the combined nrDNA ITS-morphology trees, as a sister to the remaining species of the sect. Dissitiflori. However, according to the present study, the affinity of this species to the section appeared to be questionable. Based on our molecular data, three species belonging to the section Corethrum in Iran, are pertained to the sect. Dissitiflori. In addition, our results revealed that A. pravitzii, which had been transferred to sect. Ornithopodium Bunge, belongs to the section Dissitiflori.

Keywords:

Astragalus sect. Dissitiflori , Bayesian Method , Morphology , nrDNA ITS , parsimony , phylogeny