A Preliminary Phylogenetic Study of the Subgenus Pogonophace (Astragalus) in China Based on ITS Sequence Data

摘要

The internal transcribed spacers (ITS) (including ITS1, 5.8S rRNA gene and ITS2) of Cara-gana roborovskyi and eight species of subgenus Pogonophace ( Astragalus) were sequenced, and analyzed together with other ITS data (from GenBank) of 48 species representing Astragalus and 12 related genera. The results of phylogenetic analyses suggest that the subgenus Pogonophace is not a monophyletic group. Sect. Sesbanella ( Astragalus hoantchy and A. dshimensis ) and other species of Pogonophace are nested within different major clades in the phylogenetic tree. The species of sections Bibracteola, Phyllolobium and Trichosty-lus compose a monophyletic group with a close relationship to subtribe Coluteinae instead of Astragalus . Astragalus tribidifolius and A. tanguticus might be a vicariant species pair as inferred by the ITS data.