ITS2序列鉴定筋骨草及其近缘种

Authentication of Ajuga ciliate and Its Close Species Using ITS2 Sequence

本研究对筋骨草ITS2区段测序,探讨该片段用于中药筋骨草、白苞筋骨草、白毛夏枯草和夏枯草种间分子鉴别和系统学研究中的意义,我们对核基因ITS2区段进行PCR扩增并测序,获得了该区间的完整序列,所得序列用软件MEGA4.0进行相关分析。测得筋骨草、白苞筋骨草、夏枯草和白毛夏枯草的ITS2片段长度分别为312bp,304bp,303bp,304bp。四个物种ITS2片段序列的遗传距离(Kimura2)为0.010～0.175,各个筋骨草种内的不同产地该序列无差异。用MP法根据ITS2序列的遗传距离建立系统发生树,聚类结果和形态分类相符。根据ITS2序列特征,能有效区分筋骨草和其他易混中药材。ITS2具有做为鉴定的条形码序列的潜力。应用该序列可以有效鉴定筋骨草及其近缘种。

This is an article to discuss the value of the fragments used in molecular identity and systematics of four species （Ajuga ciliata Ajuga lupulina, Prunella vulgaris, Ajuga decumbens）. The ITS2 fragments of the three species were amplified and sequenced, and were analyzed using software MEGA4.0.The length of Ajuga ciliata Ajuga lupulina, Prunella vulgaris, Ajuga decumbens fragments was 312 bp, 304 bp, 303bp and 304bp, respectively. The interspecific genetic distance （Kimura-distance） of the three species was 0.010-0.175. There was no intraspecific diversity. According to the genetic distance, phylogenetic tree was built by MP （parsimony method）, and the result showed by the phylogenetic tree was the same as morphological classification.Results indicated that the ITS2 fragments were highly conservative at an intraspecific level, and obviously diversified at the interspecific level.The ITS2 sequence could identify the Ajuga ciliata and its close species effectively.