凉茶药材鸡蛋花及其混伪品的DNA条形码鉴定

Identification of herbal tea ingredient Plumeria rubra and its adulterants using DNA barcoding

该研究应用ITS2序列作为DNA条形码鉴定凉茶药材鸡蛋花及其混伪品，共收集48份药材和基原植物样本，提取基因组DNA，通过PCR扩增ITS2序列并进行双向测序，经CodonCode Aligner拼接注释获得序列，然后应用MEGA5.0比对ITS2序列，计算种内和种间遗传距离，构建系统进化NJ树进行鉴定。结果表明，鸡蛋花ITS2序列长度为244 bp，种内遗传距离为0-0.016 6，远小于其与混伪物种间的遗传距离0.320 8-0.650 4，NJ树结果显示鸡蛋花与其混伪品均可准确区分。因此，应用ITS2条形码能够准确、有效地鉴别凉茶药材鸡蛋花及其混伪品，为鸡蛋花药材的鉴定提供了一种新的分子手段，为其使用安全提供了有力保障。

ITS2 sequence was used as a barcode to identify herbal tea ingredient Plumeria rubra and its adulterants. Genomic DNAs from forty eight samples were extracted, the ITS2 sequences were amplified and sequenced bi-direstionlly, and then assembled and obtained using CodonCode Aligner. The sequences were aligned using ClustalW, the genetic distances were computed by kimura 2-parameter （K2P） model and the Neighbor-joining （NJ） phylogenetic trees were constructed using MEGA5.0. Results showed that the length of ITS2 sequence of P. rubra were 244 bp. The intra-specific genetic distances （0-0.016 6） were much smaller than inter-specific ones between P. rubra and its adulterants（0.320 8-0.650 4）. The NJ tree indicated that P. rubra and its adulterants could be distinguished clearly. Therefore, Using ITS2 barcode can accurately andeffectively distinguish herbal tea ingredient P. rubra from its adulterants,which providesa new molecular method to identify P. rubra and ensure its safety in use.