Molecular Identification of Sophorae Tonkinensis Radix et Rhizoma Original Plant and Its Adulterants based on ITS2 DNA Barcode
基于ITS2条形码序列的山豆根基原植物及其混伪品的DNA分子鉴定

In order to discriminate Sophorae tonkinensis Radix et Rhizoma original plant and its adulterants, we collected 84 ITS2 sequences of Sophorae tonkinensis Radix et Rhizoma original plant and its adulterants belonging to 38 species from 9 distinct genera of five families and compared the divergence of these sequences. Then, the genetic distances were computed using PAUP 4b10 in accordance with the Kimura 2-Parameter (K2p) model, and the phylogenetic tree was constructed using the neighbor-joining and Kimura 2-parameter methods. The results showed that ITS2 sequences from different Sophorae tonkinensis samples in this study are identical. ITS2 sequences between Sophorae tonkinensis and its closely related species have 102 variant sites and their mean K-2p distance is 0.072. ITS2 sequences between Sophorae tonkinensis and its other adulterant species have 200 variant sites and their mean K-2p distance is 0.594. Therefore, ITS2 can be used to correctly identify Sophorae tonkinensis Radix et Rhizoma original plant and its adulterants.