九里香药材及其近缘物种ITS2分子鉴定研究

目的:应用中药材DNA条形码鉴定体系核心序列ITS2对九里香药材及其混伪品进行鉴定研究。方法:按照中药材DNA条形码分子鉴定法标准流程获取九里香药材及其混伪品ITS2序列,进行种内和种间变异分析,采用最近距离法、SNPs位点分析以及建树法,综合评估该序列的鉴定能力。结果:九里香药材及其近缘物种ITS2序列长度220~234 bp,基于K2P遗传距离不能有效区分九里香、千里香和翼叶九里香,序列分析发现九里香Murraya exotica与其他物种有3个稳定的单核苷酸多态性(SNP)位点,在UPGMA树中,不同物种的样品聚在一起,表明ITS2序列可以区分九里香药材及其近缘物种。利用中药材DNA条形码鉴定系统对44份千里香待检样品进行BLAST鉴定,结果均为正品千里香。结论:ITS2序列可用于九里香及其同属近缘物种的鉴定,为九里香药材的市场监控提供了有效手段,为其本草基因组学研究提供了依据。

Molecular Identification of Murrayae Folium et Cacumen and Its Closely Related Species Based on ITS2 Sequence

Murrayae Folium et Cacumen and its closely related species were identified by the ITS2 sequence which was the core barcode in the DNA barcoding system for identification of Chinese medicine.Methods:ITS2 sequence of Murrayae Folium et Cacumen,medicinal material and their mixed fakes were identified according to the standard procedure of Chinese medicine DNA barcode molecular identification method,and intra-and inter-specific variation analysis was performed.The nearest distance method,SNPs locus analysis,and tree building method are used to comprehensively evaluate the identification of the sequence ability.Results:The ITS2 sequence lengths of Murrayae Folium et Cacumen and its closely related species were ranged from 220 bp to 234 bp.The results indicated that K2P genetic distance analysis cannot effectively authenticate M.exotica,M.paniculata and M.alata.Sequence analysis found Murraya exotica and other related species have 3 stable SNPs location and in the UPGMA tree,it was shown that different species can be differentiated according to their monophy,indicating that ITS2 sequence can differentiate Murrayae Folium et Cacumen and its closely related species.A total of 44 samples of Murraya paniculata to be inspected were identified based on the DNA Barcoding System showing that that the inspected samples were all authentic.Conclusion:ITS2 sequence can be used to distinguish Murrayae Folium et Cacumen from its closely related species,which provide useful ways for market monitoring of Murrayae Folium et Cacumen and benefit to its herbgenomics research.