基于ITS序列的五味子DNA条形码鉴定分析

DNA barcoding analysis of Schisandra chinensis based on ITS sequences

基于五味子的内转录间隔区(Internal transcribed spacer,ITS)条形码序列,探讨五味子药材基源的鉴定方法,为该药材来源的鉴别和规范栽培种植提供参考。本研究共收集16份五味子样品,提取样品基因组DNA,PCR扩增ITS序列后双向测序,所得序列经SeqMan拼接后,采用MEGA11软件对序列进行分析比对,计算K2P遗传距离,并利用邻接(NJ)法建立系统发育树。结果表明,研究区16个样本的ITS序列结构差异较小,碱基序列相似,其中2份样本出现1个变异位点;结合遗传距离和NJ聚类树结果可看出,五味子属所有样品聚为一支,其中研究区五味子样本与来自GenBank的五味子聚为一支,南五味子属作为外群单独聚为一支,且分支具有很高的支持率,种内差异不明显,可与五味子属近缘种区分开。基于ITS序列的DNA条形码技术能够对五味子及其同科植物进行区分鉴别。

Based on the internal transcribed spacer(ITS)barcode sequences of Schisandra chinensis,this study explored the identification method of S.chinensis plants,providing reference for the identification and standardized cultivation of the source of this medicinal material.A total of 16 samples were collected in this study,and genomic DNA was extracted from the samples,followed by PCR amplification of the ITS sequence and bidirectional sequencing.After sequence assembly using SeqMan,the sequences were analyzed and aligned using MEGA11 software,K2P genetic distances were calculated,and a neighbor-joining(NJ)tree was constructed to establish the phylogenetic relationship.The results showed that the ITS sequences of the 16 samples in the study area had small structural differences and similar nucleotide sequences,with 1 variant site found in 2 samples;combining the genetic distances and NJ clustering tree results,all S.chinensis samples in the study area clustered together,forming a clade with the S.chinensis samples from GenBank,while the Kadsura samples formed an outgroup clade with a high support rate,with no clear differences within the species,allowing them to be distinguished from closely related species of Schisandra.DNA barcode technology based on the ITS sequence can differentiate and identify S.chinensis and its congeneric plants.