基于DNA条形码技术探讨中药牵牛子的基原物种问题  

Discussion on the botanical origin of Pharbitidis Semen based on DNA barcoding

作　　者：孙稚颖[1] 安顺龙 SUN Zhi-ying;AN Shun-long(Shandong University of Traditional Chinese Medicine,Ji nan 250355,China)

机构地区：[1]山东中医药大学,山东济南250355

出　　处：《时珍国医国药》2020年第7期1644-1646,共3页Lishizhen Medicine and Materia Medica Research

基　　金：山东省中医药科技发展计划项目(2017-516);2017年中医药公共卫生服务补助专项“全国中药资源普查项目”[财社(2017)66号]。

摘　　要：目的对中药材牵牛子的基原物种问题进行探讨,以确保药材来源的准确及临床疗效的稳定。方法以核基因片段ITS2序列及叶绿体基因间隔区序列psbA-trnH作为DNA条形码,对研究材料进行PCR扩增并双向测序,所得序列经CodonCode Aligner拼接后,用软件MEGA6.0进行相关数据分析,并构建NJ(邻接)树。结果圆叶牵牛、牵牛及裂叶牵牛ITS2序列种内遗传距离为0,没有遗传差异,而圆叶牵牛与牵牛、裂叶牵牛遗传距离均为0.106,牵牛与裂叶牵牛之间遗传距离为0.018。psbA-trnH序列比对后,牵牛、裂叶牵牛与圆叶牵牛样品间序列完全相同,无碱基差异。结论牵牛和裂叶牵牛亲缘关系密切,但基于两者间稳定的形态差异及遗传变异,不适宜简单处理为同一物种,可作为变种关系或近期分化的近缘物种。ITS2序列作为DNA条形码可为有效解决牵牛子基原物种问题提供重要依据。Objective This study aimed to investigate the original plant of Pharbitidis Semen, and guarantee the resource and clinical curative effect of this medical material. Methods In this study,the second internal transcribed spacer(ITS2) and chloroplast gene fragments psbA-trnH were applied and sequenced. Sequence assembly and consensus sequence generation were performed by using the CodonCode Aligner. Phylogenetic study was performed by using software MEGA6.0 in accordance with the Kimura 2-parameter(K2 P) model. And the phylogenetic tree was constructed using the neighbor-joining methods.Results The intraspecific genetic distance of Pharbitis nil, P. hederacea and P. purpurea was 0. But the interspecific genetic distance between P. purpurea and P. nil or P. hederacea was 0.106, while the genetic distance between P. nil and P. hederacea was 0.018. After psbA-trnH sequence alignment, P. purpurea, P. nil and P. hederacea have the same sequence.Conclusion P. nil and P. hederacea have closer relationship, but it was inappropriate to consider them as the same species based on the stable morphological difference and genetic variation between them. We think that P. hederacea may be as a variety of P. nil, or they may be as two closer species. ITS2 barcode can serve as a valuable marker to provide important reference for resolve the problems on the original plant of Pharbitidis Semen.

关 键 词：牵牛子 裂叶牵牛 牵牛 DNA条形码 ITS2 PSBA-TRNH 

分 类 号：R282.5[医药卫生—中药学]