基于DNA条形码的半夏属及其伪品分子鉴别

利用DNA条形码技术对半夏属及其伪品进行分子鉴定, 研究半夏属药用植物鉴定的新方法。该实验使用matK序列对半夏(Pinellia ternata)及其伪品进行扩增测序, 结合GenBank数据库数据, 分析ITS、ITS2、psbA-trnH、rbcL和matK各序列的种内与种间变异及barcoding gap, 并采用最近距离法(nearest distance)和相似性搜索算法(BLAST1)评价不同序列的鉴定能力。结果显示, matK序列的种间变异最大, rbcL序列的种内变异最小; rbcL序列的种内和种间遗传变异重叠比例最小, 其次为matK序列; 各序列的Neighbor Joining树均可明显地将不同种分开。实验结果表明, 利用DNA条形码能够准确地鉴别半夏属药用植物及其伪品, matK和rbcL序列为鉴别半夏属及其伪品的较理想条形码组合。该研究为半夏属植物的分子鉴别提供了科学依据与新的思路。

Molecular Identification of the Species of Pinellia and Its Adulterants by DNA Barcoding

We used DNA barcoding to identify the species of Pinellia and its adulterants, to authenticate medicinal plants of Pinellia. In this study, the matK region was amplified and sequenced for Pinellia ternata and its adulterants. The intraspecific and interspecific variation and barcoding gap were analyzed for ITS, ITS2, psbA-trnH, rbcL, matK region combined with GenBank database information, and the identification efficiency was evaluated based on Nearest Distance and BLAST1 methods. The results shown that matK region had the largest interspecific variation, and the rbcL region owned the smallest intraspecific variation. The rbcL region possessed the smallest overlap of intra- and interspecific genetic variation, followed by the matK region. Neighbor-joining tree of regions could divide species obviously. In conclusion, DNA barcoding could be used to accurately identify medicinal plants of Pinellia and its adulterants. The region of matK and rbcL was the ideal barcode combination for identifying the species of Pinellia and its adulterants.