Molecular Phylogeny Of Oxytropis Dc. Of Qinghai-Tibetan Plateau By Nrdnaits And Trnl-F Sequences

We researched the 19 species (47 sequence accessions) of the genus oxytropis from Qinghai-Tibetan plateau by nrDNA and trnL-F sequences. First , the sequences of the ITS and trnL-F were extracted, amplified, purification and sequenced. Then, the sequences were analysed by Max-parsimony of the MEGA software . The results are:1. The Oxytropis and the Astragalus form the two groups, and the two branches also is formed in the Oxytropis.This supported the view about monophyletic group of Oxytropis,2. ITS sequence contains more phylogenetic information than trnL-F sequence. And the ITS sequence may be more suitable than the trnL-F sequence in the analysis of the subgenus and sections.3. In the tree of ITS sequences, except for O.kansuensis and O.sericopetalal, the different geographic group can form one the branch. This displies the consistency of the ITS sequence.4. On the phylogenetic trees of nrDNA ITS and trnL-F sequences, O.Subgen. Orobia (Bunge) C.W.Chang form a well supported clade (BP=56% and 100% respectively), The results suggested that whether having septum in the carpel or not is a good character for infrageneric classification of Oxytropis. Our study don't support to merge the O. Subgen. Orobia (Bunge) C.W.Chang and O.Subgen. Oxytropis in Flora of China.5. In the level of other subgenus and sections , the two trees contain low phylogenetic information, and the sections can not form monophyletic group. And the low phylogenetic information revealed that species differentiation of Oxytropis may be late, especially in the young floristic region like Qinghai-Tibetan Plateau, circumscription of those species needs further investigation by more data.6. In our research, the two trees have more the differences because the evolution rate of the chloroplasts DNA may be low, and the trnL-F sequence maybe have the low differentiation degree or have rapid evolution. So we should do the further research and increase the species and groups , and we should also choose the more appropriate sequences. We hope that we can more and better illustrate the phylogenetic relationships between the Oxytropis, and provide more detailed informations in the systematization and utilization of Oxytropis.