Identification of Angelica sinensis and its adulterants based on ITS2 sequence / 中草药

ABSTRACT

Objective In this study, Angelica sinensis and its adulterants, close relatives were analyzed by ITS2 sequences to investigate the genetic structure from Min County, Gansu Province. Methods In this study, the internal transcribed spacer 2 (ITS2) regions of samples were amplified by PCR and sequenced bi-directionally. Obtained sequences were assembled using Codon Code 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 ITS2 region was 230 bp and base composition was GC content of 55.46% of A. sinensis in Min County. In its adulterants and close relatives of A. sinensis, the ITS2 region ranged in size from 228-233 bp and base composition was with G + C content ranged from 51.53%-65.65%. A total of 220 polymorphic sires were detected from 53 sequences, in which parsimony informative sires were up to 213. By K2P model, the intra-specific genetic distances of A. sinensis in Min County were smaller than inter-specific ones of A. sinensis and its adulterants in ITS2 regions. NJ tree and secondary structure results could distinctly differentiate quality product and adulterants. Conclusion ITS2 sequence can accurately identify the authenticity of A. sinensis, which provide a effective technology for the healthy and sustainable development in A. sinensis market.