目的采用ITS2序列作为条形码技术对菊科药用植物进行鉴别。方法选取来自西藏及四川康定、乐山和峨眉地区的菊科样品44种，提取DNA并对其进行PCR扩增，后测序，测序结果提交至GenBank；同时从GenBank上下载17条样本序列。对提交和下载的61条序列用MEGA7.0软件计算种内与种间的遗传距离，采用邻接法（neighbor-joinging，NJ）构建系统聚类树直观反应鉴定结果。从 ITS2 数据库中预测并比较样本ITS2序列的二级结构差异。结果菊科植物种间最小遗传距离0.031大于种内最大遗传距离0.009，有较明显的barcoding gap；NJ树显示种各属样本分别聚为一大枝，种内之间各自聚成小支，表现出良好的单系性；各属及各种样品ITS2二级结构存在明显差异。结论 以ITS2序列作为DNA条形码，能够对菊科药用植物进行准确、迅速的识别与鉴定，是物种间进化关系准确的分子鉴定依据，可为该科植物的分布、种群及种群数量的研究提供指导，为控制药品质量、合理开发利用及保护提供了新手段。
Using ITS2 sequence as DNA barcoding to identify medicinal plants of compositae from Kangding, Leshan and E`mei regions. The ITS2 sequences of 44 samples were amplified and bidirectional sequenced by PCR. Total 61 ITS2 sequences, together with 17 samples downloaded from the GenBank, were aligned and the genetic distances were analyzed using MEGA 7.0, and the NJ method was used to construct the system clustering tree.The secondary structure differences of ITS2 sequences were predicted and compared from ITS2 database. The minimum distance between species 0.031 was greater than the maximum distance within each specie 0.009, with obvious barcoding gap. The NJ tree showed that species differed obviously from each other, gathering in two different main branches, and the intraspecities were clustered into small branches，which showed good monophyletic behavior.Same significant differences also appeared in the secondary structures, which could both be used to separate them. Using ITS2 sequences as DNA barcode，compositae medicinal plants can be accurate and rapid identified.It is also the evolutionary relationships among species accurate molecular identification basis, for the division of plant distribution, population and population studies provide guidance, for reasonable exploitation and utilization and protection of drug quality control, providing a new methods.