目的 对竹节参及其近缘物种和混伪品进行分子鉴定，为竹节参现代化鉴定提供科学依据和保证临床疗效与用药准确性。方法 对竹节参样品进行ITS2基因片段扩增和正向测序，并从GenBank数据库下载竹节参、近缘物种和混伪品的ITS2序列，通过ITS2 database剪切最终共获得24个物种102条序列，使用DAMBE软件进行序列替代饱和度检测，利用MEGA 6.06软件进行比对、分析变异位点、计算GC含量、种内和种间遗传距离、构建NJ系统发育树，并预测ITS2二级结构。结果 竹节参ITS2序列长度均为230 bp，平均GC含量63.7%，ITS2序列平均遗传距离分析、NJ树、二级结构特征均显示竹节参与非同属混伪品和部分近缘物种（屏边三七、假人参、三叶参、野三七和越南人参）存在极大差异，能有效区分，而鉴定近缘物种西洋参、人参、三七、珠子参、羽叶三七、Panax assamicus、Panax variabilis和狭叶竹节参序列分辨率较低，具有一定局限性。结论 ITS2序列可作为鉴定竹节参与其非同属混伪品DNA条形码之一，对非同属混伪品鉴定分辨率极高，而对于鉴定其近缘物种的通用性仍有待考证，这为后续竹节参及其近缘物种种间遗传关系和亲缘关系鉴定、非同属混伪品鉴别区分和临床安全用药提供重要参考。

Objective To provide a scientific basis for the modern identification of Panax japonicus and ensure the clinical efficacy and medication accuracy,the molecular identification of P.japonicus and its related species or adulterants was carried out.Methods ITS2 sequences of P. japonicus were amplified and sequenced directionally.ITS2 sequences of related species and adulterants were downloaded from GenBank.Cutting with ITS2 database,the final dataset consisted of 102 sequences from 24 species.DAMBE program was also implemented to detect substitution saturation of ITS2 sequences.MEGA 6.06 software was utilized for sequence alignment,calculating GC content,analyzing variation sites,estimating intra-specific and inter-specific genetic distances,and finally building NJ tree.Moreover,the secondary structure of ITS2 was predicted by using the ITS2 database.Results The length of ITS2 sequences from P. japonicas was 230 bp and GC content was 63.7%.The average genetic distance analysis,NJ tree,and secondary structure characteristics of the ITS2 sequences showed that there were great differences between P japonicus and its non-identical adulterants or partial related species (P. stipuleanatus, P. pseudoginseng, P. trifolius, P. vietnamensis var.fuscidiscus,and P.vietnamensis).Howerer,the application of such method for the identification of P.japonicus and partial closely related species (P. quinquefolius,P. ginseng,P. notoginseng,P. japonicus var.major,P. japonicus var.bipinnatifidus, P. assamicus, P. variabilis,and P. japonicus var.angustifolius) had certain limitation.Conclusion The ITS2 sequence can be used as one of the DNA barcodings for the identification of P. japonicus and its non-identical adulterants at high identification rate,however,its versatility of identification between P japonicus and related species needs to be further verified.Our study provides the basis for the identification of inter-specific genetic and affinity relationship of P. japonicas and its related species,the distinguishment between P. japonicas and non-identical adulterants,and the clinical safety of P japonicas.

广东省中医药局科研项目（20151264，20161139）；广东医科大学面上培育项目（M2015015，M2016002）；国家级大学生创新创业训练计划项目（201610571002）；省级大学生创新创业训练计划立项项目（201710571075）