锦香草及其近缘种的亲缘关系ITS序列分析

为厘清锦香草及其近缘种的亲缘关系,为其杂交育种提供数据基础,收集我国锦香草及其近缘种短毛熊巴掌与长柄熊巴掌等样品46份,对供试样品核糖体基因(nrDNA)的内转录间隔区(internal transcribed spacer,ITS)序列进行分析,并构建系统进化树,对其系统发育关系进行研究。结果表明:供试材料的ITS1、ITS2和5.8S的序列长度分别为246、230、160~161 bp;ITS1与ITS2序列存在变异位点426个,信息位点232个;5.8S序列存在202个变异位点,信息位点84个。根据ITS序列构建进化树:供试材料可分为2支,锦香草与短毛熊巴掌在进化树中聚为一支,分支内部互相嵌入;长柄熊巴掌单独聚成一支。以上结果显示,锦香草、短毛熊巴掌亲缘关系较近,它们与长柄熊巴掌亲缘关系较远,该结果支持《Flora of China》将短毛熊巴掌处理为锦香草的异名,长柄熊巴掌为独立种。

Analysis of inter-species relationship of Phyllagathis cavaleriei and its related species by use of ITS sequences

In oder to clarify the phylogenetic relationship between Phyllagathis cavaleriei and its related species and provide data basis for its cross breeding,46 samples were collected from China, including P. cavaleriei and its related species P. cavaleriei var. tankahkeei and P. cavaleriei var. wilsoniana in China. Sequence of the internal transcribed spacer (ITS) of the ribosomal gene (nrDNA) of the tested samples was analyzed, and phylogenetic tree was constructed to study the phylogenetic relationship. The results showed that length of ITS1, ITS2, and 5.8S sequences of 46 materials were 246, 230, and 160-161 bp, respectively. Total 426 variable sites were found in ITS1 and ITS2 sequences with 232 informative sites. There were 202 mutation sites and 84 informative sites in 5.8S sequence. Based on ITS sequence, an evolutionary tree was constructed, materials could be divided into two branches. P. cavaleriei and P. cavaleriei var. tankahkeei were clustered into one branch in the cluster tree, and the branches were embedded into each other, while P. cavaleriei var. wilsoniana was clustered into a single branch. The above results showed that P. cavaleriei was closely related to P. cavaleriei var. tankahkeei, while P. cavaleriei var. wilsoniana was far related. The results supported Flora of China to deal with P. cavaleriei var. tankahkeei as a different name of P. cavaleriei, P. cavaleriei var. wilsoniana was a separate species.