应用ITS2条形码鉴定中药材麻黄

Using ITS2 barcode to identify Ephedrae Herba

目的:应用ITS2条形码快速、准确地鉴定中药材麻黄,为其用药安全、有效提供保障。方法:提取麻黄药材及其同属密切相关种的DNA、扩增ITS2序列并测序,采用软件CodonCode Aligner V3.0对测序峰图进行校对拼接,并进行质量控制。应用MEGA5.0软件计算种内种间Kimura 2-parameter(K2P)遗传距离。应用相似性搜索法、最近距离法进行鉴定分析,并构建NJ系统聚类树直观反映鉴定结果。结果:麻黄药材基原物种种内K2P遗传距离分布于0～0.002,基原物种与其他密切相关种之间的K2P遗传距离分布于0.004～0.034;几种鉴定方法分析结果表明ITS2序列能将麻黄药材与其他密切相关种鉴别开。结论:ITS2条形码适用于鉴别中药材麻黄,进一步验证了DNA条形码技术鉴定中药材的有效性。

Objective： To identify Ephedrae Herba using the ITS2 barcode and to secure its quality and safety in medication.Method： Total genomic DNA was isolated from Ephedrae Herba and its closely related species.Nuclear DNA ITS2 sequences were amplified,and purified PCR products were 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 and neighbor-joining（NJ） methods.Result： The intra-specific genetic distances of Ephedrae Herba were ranged from 0 to 0.002.The inter-specific genetic distances between Ephedrae Herba and its closely related species were ranged from 0.004 to 0.034.All the three methods showed that ITS2 could discriminate Ephedrae Herba from its closely related species correctly.Conclusion： The ITS2 region is suitable to be used for authentication of Ephedrae Herba,and our study further confirmed the effectiveness of ITS2 to identify traditional Chinese medicinal materials.