目的 利用DNA条形码鉴定技术，快速、准确地鉴别黄芩及其同属近缘种（易混品）。方法 提取黄芩及其同属近缘种的DNA，对ITS和psbA-trnH序列扩增和测序，计算物种种内种间Kimura 2-parameter （K2P）遗传距离。采用相似性搜索法、最近距离法、构建Neighbor-joining（NJ）系统聚类树等方法进行鉴定分析。结果 黄芩及其同属近缘种种间的ITS和psbA-trnH序列的遗传距离为0.067 97～0.088 80和0.050 61～0.057 37，明显大于黄芩种内的遗传距离0～0.006 40和0～0.003 11。ITS和psbA-trnH分子系统树显示，黄芩8个居群个体均聚为一单系分支，支持率均为100%，与其5个同属近缘种很好地区分开。3种鉴定方法表明，ITS和psbA-trnH序列适合鉴别黄芩及其同属近缘种。结论 ITS和psbA-trnH序列可以有效准确鉴别中药材黄芩及其近缘种。

Objective To fastly and acurrately authenticate Scutellaria baicalensis and its closely related species using DNA barcoding technique. Methods Total genomic DNA was isolated from S. baicalensis and its related species. Nuclear DNA ITS and chloroplast gene psbA-trnH sequences were amplified and sequenced. The Kimura 2-parameter (K2P) distances were calculated. Identification analyses were performed using BLAST1, nearest distance, and Neighbor-joining (NJ) methods. Results The genetic distances ofITS and psbA-trnH between S. baicalensis and its closely related species were (0.067 97—0.088 80) and (0.050 61—0.057 37), which were obviously higher than those in the intra-species of S. baicalensis (0—0.006 40) and (0—0.003 11). The NJ tree of ITS and psbA-trnH indicated that the eight geographical populations of S. baicalensis formed a monophyletic clade [bootstrap (BS) = 100%]. All the three methods showed that ITS and psbA-trnH could discriminate S. baicalensis from its closely related species correctly. Conclusion ITS and psbA-trnH are two efficient barcodes for the authentication of S. baicalensis and its related species.

科技部国家星火计划项目（2012GA750004）；国家自然科学基金面上项目（31070171，31270236）