Identification of Bupleurum marginatum var. Wall. ex DC stenophyllum (Wolff) Shan et Li and its analogues based on ITS2 barcode / 中草药

ABSTRACT

Objective: DNA barcoding technology, a molecular identification method, is applied to distinguish Bupleurum marginatum var. stenophyllum from its analogues in order to ensure the quality and clinical curative effect. Methods: In this study, the internal transcribed spacer 2 (ITS2) regions of 50 samples were amplified by PCR and sequenced bi-directionally. Obtained sequences were assembled using CodonCode Aligner. The genetic distances were computed by MEGA 6.0 in accordance with the kimura 2-parameter (K2P) model and the phylogenetic tree was constructed by Neighbor-joining (NJ) method. Moreover, the secondary structure of ITS2 was predicted using ITS2 database websites. Results: The intra-specific genetic distances were smaller than inter-specific ones in ITS2 regions of B. marginatum var. stenophyllum. The NJ tree and secondary structure results could distinctly differentiate B. marginatum var. stenophyllum and its analogues. Conclusion: ITS2 sequence can scientifically and reliably identify the authenticity of B. marginatum var. stenophyllum and could provide more new and reliable techniques to ensure clinical safety of this traditional Chinese medicine.