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目的:积雪草容易与多种混淆品相互混淆,本研究拟基于mat K序列探讨积雪草与其混淆品鉴定的新方法。方法:从Gen Bank核酸数据库下载积雪草、过路黄、连钱草和乌蔹莓的mat K序列,应用Clustal X 2.1软件进行SNP鉴别位点分析,应用MEGA5.0软件计算种内种间(K2P)遗传距离和构建邻接(NJ)系统聚类树。结果:获得积雪草与过路黄各5个mat K序列及连钱草和乌蔹莓各1个mat K序列,分析显示积雪草与其混伪品的mat K序列存在较大差异,具有近百个SNP位点,且其中多是积雪草特有的,可用于分子鉴定。且积雪草最大种内K2P遗传距离0.001,远远小于其与混伪品的种间K2P遗传距离0.242~0.293,构建的系统发育树显示积雪草与其混淆品可明显分开。结论:综合以上分析,mat K序列为鉴定积雪草及其混淆品提供了新的分子鉴定方法。
OBJECTIVE: Centella asiatica easily confused with many kinds of confusions. In this study, we will explore a new method for the identification of Centella asiatica and its adulterants based on mat K sequence. Methods: The mat K sequence of Centella asiatica, Rhizoma Chuanxiensis, Betula albidiflorum and Ribes nigra was downloaded from Gen Bank’s nucleotide database. The SNPs were identified using Clustal X 2.1 software. K2P) genetic distance and construction neighbor (NJ) phylogenetic tree. RESULTS: Five mat K sequences of Centella asiatica and Passepartout yellow and one mat K sequence of each of them were obtained. The analysis showed that the mat K sequences of Centella asiatica and its adulterated products are quite different, One hundred SNP sites, of which Centella particularly are endemic, can be used for molecular identification. Moreover, the genetic distance of K2P in the largest species of Centella asiatica was 0.001, far less than the genetic distance of K2P between species and its adulterants ranged from 0.242 to 0.293. The phylogenetic tree constructed showed that Centella asiatica and its adulterants were obviously separated. Conclusion: Based on the above analysis, mat K sequence provides a new molecular identification method for the identification of Centella asiatica and its confusions.