Cytochrome C oxidase subunit I barcodes provide an efficient tool for Jinqian Baihua She (Bungarus parvus) authentication

To test the feasibility of DNA barcoding for accurate identification of Jinqian Baihua She and its adulterants. Standard cytochrome C oxidase subunit I (COI) gene fragments were sequenced for DNA barcoding of 39 samples from 9 snake species, including Bungarus multicinctus, the officially recognized origin animal by Chinese Pharmacopoeia, and other 8 adulterate species. The aligned sequences, 658 base pairs in length, were analyzed for divergence using the Kimura-2-parameter (K2P) distance model with MEGA5.0. The mean intraspecific K2P distance was 0.0103 and the average interspecific genetic distance was 0.2178 in B. multicinctus, far greater than the minimal interspecific genetic distance of 0.027 recommended for species identification. A neighbor-joining (NJ) tree was constructed, in which each species formed a monophyletic clade with bootstrap supports of 100%. All the data were submitted to Barcode of Life Data system version 3.0 (BOLD, http://www.barcodinglife.org) under the project title "DNA barcoding Bungarus multicinctus and its adulterants". Ten samples of commercially available crude drugs of JBS were identified using the identification engine provided by BOLD. All the samples were clearly identified at the species level, among which five were found to be the adulterants and identified as Dinodon rufozonatum. DNA barcoding using the standard COI gene fragments provides an effective and accurate means for JBS identification and authentication.