Molecular Phylogeny Of Clniotnia Udensis Inferred From NrDNA ITS Sequence

Clniotnia udensis Trautv.et Mey.,a perennial herb,belongs to the genus Clintonia Raf in the tribe Polygonateae(Liliaceae).Two ploid levels exist in this species(2n=14 and 2n=48).The diploid C.udensis is distributed from Northwest China's Yunnan Province to Russia's Primorskiy Kray,while the tetraploids are distributed in Yunnan,Himalayas,Japan,Mulinzi in Hubei and a narrow area in the northern hillside of Mt.Hualongshan below 2200 altitude in Shaanxi province.The characters of the shape in leaf,fruit,inflorescence and pollen et.al differentiate greatly in the inner species,but no differences are showed in ploid level,the results infer the species is in the stage of great differentiation.ITS sequences of 13 Clintonia undensis diploid populations and 5 tetraploid populations are reported by cloned sequencing. Sequence analysis shows that the length of ITS1 varies from 171bp to 270 bp;the length of ITS2 is from 205bp to 238 bp and 5.8S is from 162bp to 164bp.Among the 18 ITS sequences 289 sites are informative.The contents of GC of the sequences are between 45.83%～54.13%.Genetic distances are gained by MEGA4.0,the average genetic distance of 18 populations is 0.249,the results indicate that ITS sequences among the 18 populations differentiate significantly.Correlative analysis by SPSS reveals that genetic distances and geographical distances in these populations show positive correlation(r=0.372,P=0.01).Phylogenetic analysis based on the internal transcribed spacers(ITS)of 18-26S rDNA have been conducted,using maximum parsimony method(MP), neighbor-joining method(NJ)and minimum evolution(ME),phylogenetic trees are reconstructed and origin of tetraploids Clintonia undensis and the relationship among the populations are discussed.Phylogenetic analysis of ITS sequences using PAUP4. 0b4a software obtained the MP trees(Length=1056,CI=0.630 and RI=0.684) when the gaps are treated as missing.The results indicate that the diploid populations and tetraploid populations from same region are always clustered.The origin of Clintonia undensis polyploidy is polytopic.