Identification of Rubi Parvifolii radix and its adulterants using DNA barcoding / 中国药学杂志

ABSTRACT

OBJECTIVE: To identify Rubi Parvifolii Radix from its adulterants using ITS2 sequence. METHODS: All the DNA of Rubi Parvifolii Radix and its adulterants were extracted. All the sequences were assembled using the CondonCode Aligner V3.7.1. The Kimura 2-parameter (K2P) genetic distances and the neighbor joining (NJ) phylogenetic tree were calculated by using MEGA5.1. RESULTS: The ITS2 sequences were succesfully amplified and sequenced. The length of ITS2 sequences of Rubus parvifo-lius was 212 bp, and the average GC content was 57.42%. Among 20 ITS2 sequences of R. parvifolius, three transversions were detected at site 66, 118 and 177. The maximum intra-specific K2P distance of R. parvifolius was 0.014, lower than the minimum interspecific K2P distances of adulterants, except for R. coreanus. Additionally, the ITS2 sequences of all the polytypic species were separated into pairs of divergent clusters in the NJ tree and R. parvifolius can be distinguished clearly from its adulterants. The ITS2 sequences of 23 samples of Rubi Parvifolii Radix collected from different herb markets, were successfully amplified. The NJ tree analysis indicated that 13 samples clustered with R. parvifolius, while the other 10 samples were clustered into other divergent clusters. CONCLUSION: ITS2 Sequence can be used as DNA barcode to correctly identify Rubi Parvifolii Radix from its adulterant.