应用DNA条形码ITS2序列对市售药材黄柏的鉴定研究

目的：应用DNA条形码ITS2序列鉴定市售黄柏药材及其混伪品，保障药材质量及用药安全。方法：对90份药材及其基原植物样品进行DNA提取，通过聚合酶链式反应（PCR）扩增ITS2序列并进行双向测序，运用CodonCode Aligner V3.7.1对测序峰图进行校对拼接，去除低质量区和引物区，得到ITS2序列，运用MEGA 6.1对序列进行比对分析，基于K2P遗传距离构建系统聚类树。结果：90份实验样品均能提取到DNA，其DNA经PCR扩增、测序，序列拼接剪切后均能得到高质量ITS2序列。川黄柏和关黄柏基原物种黄皮树和黄檗的种内最大K2P遗传距离分别为0.018和0.004，均远小于其与混伪品的种间最小K2P遗传距离（0.051和0.056）；NJ树结果显示川黄柏和关黄柏聚为一支，其混伪品各自聚为一支。结论：基于ITS2序列的DNA条形码技术可准确、有效地鉴定市售黄柏药材及其混伪品，为其市场监管及用药安全提供了一种高效的技术方法。

DNA Barcode Identification of Adulterants from Commercial Cortex Phellodendri Using ITS2 Sequence

In this study,Cortex phellodendri and its adulterants were identified by ITS2 sequence.The genomic DNAs were extracted from ninety samples,and the ITS2 sequences were amplified and bidirectionally sequenced.All the sequences were assembled by CodonCode Aligner V3.7.1.The genetic distances were computed by Kimura 2-parameter(K2P)model and Neighbor-joining (NJ) phylogenetic tree was constructed by MEGA 6.1.The results showed that the maximum intraspecific K2P genetic distance of Phellodendron chinense and Phellodendron amurense were 0.018 and 0.004,which were smaller than the minimum interspecific K2P genetic distance (0.051 and 0.056).The NJ tree showed that ITS2 sequence of P.chinense and P.amurense clustered into one clade,while each species of the adulterants clustered into one clade respectively.It was concluded that using ITS2 barcode can distinguish Cortex phellodendri and its adulterants,which provided an efficient technological method to identify Cortex phellodendri and its adulterants and had a great help for the market supervision.