基于ITS2条形码序列的京大戟及其易混品的DNA分子鉴定

Molecular identification of Euphorbia pekinensis and its adulterants using ITS2 barcode sequence

目的对京大戟及其易混品进行DNA分子鉴定,以保证京大戟的用药安全。方法对京大戟及其18种易混品共29份样品的内转录第二间隔区(ITS2)条形码序列进行分析。对京大戟ITS2序列种内序列变异,京大戟与其易混品间的种间序列差异进行分析比较,并构建京大戟及其易混品的NJ树。结果京大戟ITS2序列种内变异较小,平均K-2P距离为0.0092,最大K-2P距离为0.0138。京大戟与其易混品间的种间序列差异较大,种间K-2P距离的平均值为0.3395,最小种间K-2P距离为0.0427。京大戟在NJ树上聚为独立一支,表现出单系性。结论 ITS2条形码可以对京大戟及其易混品进行DNA分子鉴定,在中药材鉴定中具有重要的应用价值。

Objective To identify Euphorbia pekinensis and its adulterants,and assure the safety of this medicinal material.Methods In this study,the ITS2 barcode sequences of 29 samples of 19 species of Euphorbia pekinensis and its adulterants have been analyzed.The intra-specific variation of Euphorbia pekinensis,as well as the inter-specific divergence between Euphorbia pekinensis and its adulterants had been calculated.NJ tree of Euphorbia pekinensis and its adulterants had been constructed using MEGA5 software.Results Euphorbia pekinensis possessed low intra-specific sequence variation.The average intra-specific K-2P distance of Euphorbia pekinensis was 0.0092,and the maximum was 0.0168.The inter-specific sequence divergence between Euphorbia pekinensis and its adulterants is relatively high.The average inter-specific K-2P distance between ＂Euphorbia pekinensis and its adulterants was 0.3395,and the minimum was 0.0427.In the cluster dendrogram,Euphorbia pekinensis showed monophyletic.Conclusion Euphorbia pekinensis and its adulterants can be correctly identified using ITS2 barcode sequence,and the ITS2 region showed potential use to identify traditional Chinese medicine.