应用DNA条形码技术鉴定中药材灯心草

目的:应用植物类药材通用条形码ITS2鉴定中药材灯心草。方法:对灯心草药材及其密切相关种进行PCR扩增和测序,运用CodonCode Aligner对所获ITS2序列进行拼接。应用MEGA5.0软件计算Kimura 2-parameter(K2P)遗传距离。采用相似性搜索法、最近距离法、PWG距离法及构建NJ(邻接)系统聚类树等方法进行鉴定分析。结果:灯心草药材种内K2P遗传距离在0～0.005,远远小于灯心草与其他密切相关种之间的K2P遗传距离(0.215～0.614);4种鉴定方法均表明ITS2序列可以有效区分灯心草与其密切相关种。结论:植物类药材通用条形码ITS2适用于鉴定中药材灯心草,进一步证明了ITS2对中药材的鉴定能力。

Identification of Junci Medulla using DNA barcoding technique

Objective : To identify Junci Medulla using the ITS2 barcode. Method : The ITS2 regions of Juncus effuses and its closely related species were PCR amplified and sequenced. Sequence assembly and consensus sequence generation were performed using the CodonCode Aligner. The Kimura 2-Parameter (K2P) distances were calculated using software MEGA 5.0. Identification analyses were performed using BLAST1, Nearest Distance, PWG Distance and neighbor-joining (NJ) methods. Result : The intra-specific genetic distances of J. effuses were ranged from 0 to 0.005, which were far lower than inter-specific genetic distances between J. effuses and its closely related species (0.215-0.614). All the four methods showed that ITS2 could discriminate J. effuses from its closely related species correctly. Conclusion : The ITS2 region is an efficient barcode for authentication of Junci Medulla, and our study further confirmed the ability of ITS2 to identify traditional Chinese medicinal materials.