Molecular authentication of Traditional Chinese Medicine Acanthopanacis Cortex (“Wu Jia Pi”) and its analoguesbased on DNA barcode marker ITS2, matK and psbA-trnH

Objective To distiguish Acanthopanacis Cortex from its analogues, and to screen suitable DNA barcodes, the ITS2 and its secondary structure, matK and psbA-trnH were used. Methods A total of 74 sequences encompassing 6 taxa representing Acanthopanacis Cortex and its analogues were collected from its main distributing area and GenBank. Samples were assessed by PCR amplification, sequencing, sequence quality, extent of specific genetic divergence, DNA barcoding gap, and the ability to discriminate between species. Results The results of NJ trees based on the three DNA barcodes showed that all the species could be distinguished from each other and branched independently, showing good monophyly. The topological structure of ITS2 PNJ phylogenetic tree was consistent with that of NJ tree. The interspecific genetic distance between Acanthopanacis Cortex and its analogues was significantly greater than the intraspecific genetic distance. The secondary structure of ITS2 was significantly different among species. Conclusion All the three DNA barcodes could be used as molecular marker to differentiate Acanthopanacis Cortex from its analogues, however the intergeneric identification efficiency was the best in ITS2, followed by matK and psbA-trnH. Therefore, ITS2 as the dominant identification method supplemented by matK and psbA-trnH DNA barcodes are recommended in this study to provide scientific basis for Acanthopanacis Cortex identificationand safety of clinical use.