基于叶绿体DNA序列的多基原黄精分子鉴定

Molecular Identification of Polygonati Rhizoma from Different Plant Origins Based on Chloroplast DNA Sequences

目的:通过分析rpl20-rps12、trnL-trnF及psbA-trnH序列变异特点,评价其对3种不同基原黄精的鉴定能力。方法:分别提取3种基原黄精总DNA,以rpl20-rps12、trnL-trnF及psbA-trnH引物进行聚合酶链式反应(PCR)扩增和测序。采用MEGA 5软件寻找其特异位点,计算样品K2-P(Kimura 2-parameter)遗传距离,并构建邻接(neighbor-joining,NJ)系统聚类树。结果:rpl20-rps12、trnL-trnF及psbA-trnH序列长度分别为722~737、293、457~531 bp,简约信息位点占比分别为0.4%、1.0%和2.4%。rpl20-rps12和psbA-trnH序列中种内最大遗传距离均小于种间最小遗传距离。基于3个序列构建的NJ树显示,3种基原黄精都表现出良好单系性,能明显区分。结论:从序列特点和种内、种间变异性综合分析,rpl20-rps12序列更适宜黄精的基原鉴定。

Objective:To evaluate ability of 3 chloroplast regions(rpl20-rps12,trnL-trnF,and psbA-trnH)to identity Polygonati Rhizoma derived from 3 Polygonatum species(Polygonatum sibiricum Red.,P.cyrtonema Hua.,P.kingianum Coll.et Hemsl.).Methods:Genomic DNA of Polygonati Rhizoma samples derived from the 3 species was extracted,and three chloroplast sequences were amplified and sequenced.MEGA 5 was employed for identification of specific sites and Kimura 2-parameter(K2-P)distance calculation,and neighbor-joining(NJ)method was used for the construction of the phylogenetic tree.Results:rpl20-rps12,trnL-trnF,and psbA-trnH were 722-737,293,and 457-531 bp,respectively,and the proportions of parsimony-informative site were 0.4%,1.0%,and 2.4%,respectively.The maximum intra-specific K2-P distance was smaller than the minimum inter-specific K2P distance for rpl20-rps12 and psbA-trnH.According to the phylogenetic tree,the Polygonati Rhizoma samples derived from the 3 species were monophyletic and can be separated successfully by the 3 sequences.Conclusion:Comprehensive analysis of sequence characteristics and genetic distance shows that rpl20-rps12 is more suitable for the identification of Polygonati Rhizoma.