应用位点特异性引物鉴定白花蛇舌草

目的:建立一种简便实用的白花蛇舌草药材的DNA分子鉴定方法.方法:收集目前市场上出现的白花蛇舌草及伪品共9种,分别提取总DNA,扩增rDNA ITS-2区序列,对比所有样品的该段核苷酸序列,并设计能专一性鉴别白花蛇舌草的位点特异性引物.结果:白花蛇舌草及其混淆品在ITS-2区的序列有显著差异.用位点特异性引物对所有样品DNA进行PCR扩增,只有白花蛇舌草有明显的约392 bp扩增产物,而其它8种植物在同等条件下无阳性产物.结论:所设计的鉴别引物对白花蛇舌草有高度的特异性.

Application of Allele-Specific Primer in the Identificatin of Hedyotis diffusa

Objective: To develop a convenient and effective method for the identification of Hedyotis diffusa. Methods: DNA templates were extracted from H. diffusa and its adulterants samples on commercial markets. And DNA fragments of rDNA ITS 2 regions were amplified and sequenced subsequently. ITS 2 sequences of all samples were aligned. The allele specific primer was designed for distinguishing H. diffusa. Results: The nucleotide difference between H. diffusa and 8 other species is obvious in the ITS 2 region. In addition, the allele specific primers were employed to amplify the DNA from H. diffusa and 8 other species. The result indicated that a 392 bp DNA fragment was amplified from H. diffusa, whereeas no any fragment was amplified from 8 other species under the same reaction condition. Conclusion: The primers designed in the present study were highly specific for H. diffusa. They could be used as key components in the H. diffusa identification kit.