基于DNA条形码鉴定植物药常山及其混伪品

Identification of Dichroa febrifuga and its adulterants based on DNA barcoding technology

虎耳草科(Saxifragaceae)常山属(Dichroa)植物常山(Dichroa febrifuga Lour.)是我国著名的抗疟药物。但目前全国各地使用较为混乱,代用品、混淆品多,鉴定困难。本研究收集常山及其混伪品6种,共64份样品,利用DNA条形码和二维DNA条形码技术进行物种鉴定研究。研究结果表明,DNA条形码技术可准确鉴定常山及其混伪品,20%的常山样品存在混伪现象,混伪品主要为阔叶十大功劳(Mahonia bealei(Fort.)Carr.)。常山ITS2序列长度为230 bp,种内K2P遗传距离为0~0.0253,常山及其混伪品种间K2P遗传距离为0.152~0.748。基于ITS2序列构建的NJ树显示,常山及其混伪品能够明显区分,可为临床安全用药提供科学依据。成功构建常山的二维DNA条形码鉴定体系,实现"互联网+"的跨平台信息交换,可为二维DNA条形码技术在流通监管领域的实践应用提供理论基础。

As a famous traditional Chinese medicine, Dichroa febrifuga Lour., belonging to the genus Dichroa in the family Saxifragaceae, is used to treat malaria and eliminate phlegm. However, considerable substitution and adulteration of D. febrifuga has occurred in China due to the difficulty in identifying D. febrifuga from its adulterants by morphological methods alone. In this study, a total of 64 samples labeled as D. febrifuga or its adulterants, belonging to six species, were collected and identified by DNA barcoding technology. Two-dimensional DNA barcodes were used to construct an ＇ Internet Plus＇ identification system, which benefits the cross-platform communication of DNA barcode information. Our results indicated that 20% of D. febrifuga samples were adulterants, with Mahonia bealei being predominant. In addition, the length of the ITS2 sequence of D. febrifuga was 230 bp. The intraspecific K2P genetic distance was 0 - 0.0253, whereas the interspecific K2P genetic distance was 0.152 - 0.748. A neighbor-joining tree showed that D. febrifuga differed markedly from its adulterants, which provides pivotal molecular evidence for resource identification and clinical security. The establishment of the ＇ Internet Plus＇ two-dimensional DNA barcode system could provide a theoretical basis for the application of two-dimensional DNA barcodes in the trade and standardization of Chinese medicinal material.