应用ITS2序列鉴定垂盆草及其混伪品

Authentication of Sedum sarmentosum and Its Adulterants by Application of ITS2 Sequences

目的:通过对药食同源植物垂盆草及其混伪品进行分子鉴定,以保证该植物的临床药效及食用安全。方法:通过对样品DNA进行PCR扩增,获得ITS2基因片段,纯化后的PCR产物进行双向测序,运用CodonCode Aligner进行序列的拼接、MEGA5.0软件进行序列分析并构建K2P模型的NJ树。结果:垂盆草与其混淆品ITS2序列间存在明显变异,种内遗传距离小于种间遗传距离,从NJ树中可以明显看出不同来源垂盆草聚为一支,与混伪品可以很好地区分。结论:ITS2序列可有效地鉴别药用植物垂盆草及其混淆品,对中药鉴定具有潜在的应用价值。

Objective ：To identify medicinal and edible Sedum sarmentosum and its adulterants, and to secure the clinical efficacy and edible safety of this plant. Methods：The PCR technique was performed to obtain the ITS2 regions and the purified PCR products were sequenced bi-directionally. Sequences were assembled by the CodonCode Aligner and analysed by MEGAS. 0. The neighbor-joining phylogenetic tree was constructed based on the Kimura 2-parameter model. Results： The ITS2 regions of S. sarmentosum exhibited obvious difference with those of the adulterants. The intraspecific variation was less than interspecific genetic distance. All samples of S. sarmentosum showed monophyletic on NJ tree,and distinguished from its adulterants. Conclusion：ITS2 can be used as a effective marker for identifying S. sarmentosum and its adulterants, and it has a potential applications in the identification of traditional Chinese medicine.