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目的构建鬼针草Bidens pilosa及其与近缘种之间系统发育关系,准确鉴别鬼针草及其近缘种。方法提取鬼针草及其近缘种DNA,对核基因ITS片段和叶绿体基因psbA-trnH序列扩增和测序,计算物种种内、种间Kimura 2-parameter(K2P)遗传距离。采用最近距离、相似性搜索、构建Neighbor-joining(NJ)系统聚类树3种方法进行鉴定分析。结果 ITS和psbA-trnH分子系统树支持鬼针草不同居群样本聚为一单系分支,支持率为79%和87%;其中,鬼针草与白花鬼针草构成一单系分支,金盏银盘与婆婆针构成姐妹群分支,上述两分支ITS和联合数据支持率均为100%;狼把草与柳叶鬼针草、大狼把草构成一单系分支(ITS和联合数据支持率为100%,psbA-trnH数据支持率为96%)。鬼针草及其近缘种种间ITS和psbA-trnH序列的遗传距离为0.007 94~0.128 80和0.005 18~0.074 52,均远大于鬼针草种内遗传距离0~0.001 59和0~0.002 52。结论鬼针草与白花鬼针草亲缘关系最近,金盏银盘与婆婆针构成姐妹群关系,狼把草与柳叶鬼针草、大狼把草亲缘关系较近。ITS和psbA-trnH序列可以准确鉴别鬼针草及其近缘种。
Objective To construct the phylogenetic relationship between Bidens pilosa and its related species, and to accurately identify Bidens pilosa and its related species. Methods DNA from Bidens steppe and its related species was extracted and the psbA-trnH sequence of nucleus gene and chloroplast gene were amplified and sequenced. The genetic distances between species and inter-species Kimura 2-parameter (K2P) were calculated. Neighbor-joining (NJ) phylogenetic tree was constructed based on nearest distance and similarity search. Results The phylogenetic tree of ITS and psbA-trnH supported different populations of Bidens bipinnata as a single branch with the support rate of 79% and 87%, respectively. Among them, Bidens bipinnata formed a single branch with gold Silver plate and mother-in-law constitute a sister group branch, the two branch ITS and joint data support rate was 100%; Wolf grass and willow grass, Wolf wolf grass constitute a single branch (ITS and joint data support Rate of 100%, psbA-trnH data support rate of 96%). The genetic distances between ITS and psbA-trnH sequences of Bidens bipinnata and its neighboring species ranged from 0.007 94 to 0.128 80 and from 0.005 18 to 0.074 52, both of which were far greater than the genetic distances 0 to 0.001 59 and 0 to 0.002 52 . Conclusion The relationship between Bidens officinalis and C. przewalskii is relatively recent. The relation between the golden silver plate and the mother-in-law constitutes a sister group, and the wolf grass and the willow grass and the wolf grass are close relatives. ITS and psbA-trnH sequences can accurately identify Bidens grass and its related species.