Using ITS2 Sequence to Identify Descurainiae, Lepidii Semen and Its Adulterants / 世界科学技术-中医药现代化

ABSTRACT

Descurainiae, Lepidii Semen and their it adulterants were identified by analysising their ITS2 sequences. The genomic DNA was extracted from 46 samples including Descurainiae and Lepidii Semen and their it adulterants. Their ITS2 sequences were amplified, and purified PCR products were sequenced. Sequence assembly and consensus sequence generation were performed using CodonCode Aligner v 4.25. The genetic distances, variable sites and the neighbor-joning (NJ) phylogenetic tree were computed by MEGA 6.0 in accordance with the Kimura 2-parameter (K2P) model. The results showed that the intra-specific genetic distances of Descurainia sophia and Lepidium apetalum were 0.021 and 0.010, which were smaller than inter-specific ones of D. sophia, L. apetalum and their adulterants. The NJ tree showed that both D. sophia and L. apetalum were clustered into one monophyletic branch, and clearly separated with their sibling species. Therefore ITS2 sequence was able to identify Descurainiae and Lep-idii Semen and its adulterants to ensure the quality of medicines and clinical efficacy.