ITS2序列鉴定大蓟、小蓟药材及其近缘混伪品

Identification of Cirsium japonicum,Cirsium setosum and Their Adulterants Based on ITS2 Sequence

目的:应用ITS2序列鉴别大蓟、小蓟药材及其近缘混伪品,以保障临床用药准确。方法:收集大蓟、小蓟药材的基原物种蓟和刺儿菜及其近缘混伪品,经DNA提取、PCR扩增、测序和序列拼接等步骤,获得ITS2序列,结合Gen Bank载序列共14个物种54条序列,用MEGA6.0对序列进行比对分析,计算种内种间K2P(Kimura 2-Parameter)遗传距离,构建系统邻接(NJ)树。结果:ITS2序列分析表明,蓟和刺儿菜种内变异位点数均远小于其与混伪品种间变异位点,以上2个物种种内最大(平均)K2P距离均小于其与混伪品种间最小(平均)K2P距离;基于ITS2序列的系统NJ树可以将蓟和刺儿菜及其近缘混伪品很好地区分开,且各物种均单独成支。结论:ITS2序列可以很好地鉴定大蓟、小蓟药材及其近缘混伪品。

Objective： To identify C. japonicum,C. setosum and their adulterants through ITS2 Sequence method to ensure clinical medication safety. Methods： DNA was extracted from C. japonicum and C. setosum,which were the original plant samples of Cirsii Japonici Herba and Cirsii Herba together with their adulterant and ITS2 sequences were obtained by PCR,sequencing,and sequence assembly. Totally,54 sequences of 14 species were downloaded from the Gen Bank,using MEGA 6. 0 to align all sequences,calculating the intraspecific and interspecific Kimura-2-Parameter（K2P） genetic distance and constructing NJ tree. Results： It suggested that the intraspecific variation locis between C. japonicum and C. setosum were much less than that between adulterants. The maximum（average） intraspecific distance of C. japonicum and C. setosum was lower than the minimum（average）interspecific distance of adulterants. Based on ITS2 sequences,this identification method of NJ Tree were effective and clearly distinguished C. japonicum and C. setosum from their adulterant. Also,all species showed obvious monophyly. Conclusion： The sequence of ITS2 identified the herbal materials of C. japonicum,C. setosum and their Adulterants.