Molecular authentication by multiplex-PCR of three similar medicinal plant species: Cynanchum wilfordii, Cynanchum auriculatum and Polygonum multiflorum (Fallopia multiflorum).

Abstract

Polygoni Multiflori radix (Hashuoh in Korean and Heshouwu in Chinese) and Cynanchi Wilfordii Radix (Baekshuoh in Korean and Beishouwu in Chinese) are important oriental medicinal herbs in Korea, Japan, and China. The trnL (tRNA-Leu) intron region was targeted for molecular analysis with universal primers to discriminate the morphologically similar to Polygoni multiflori Radix and Cynanchi wilfordii radix from their adulterant, Cyanchum auriculatum. Analysis of sequencing data revealed DNA polymorphisms in the three species, including single nucleotide polymorphisms (SNP) sites, insertions, and deletions. Based on these DNA polymorphisms, specific primers were designed for each of the three species. Multiplex polymerase chain reaction (PCR) with specific primers was conducted for molecular authentication of Polygonum multiflorum, Cyanchum wilfordii and C. auriculatum. The established multiplex-PCR system effectively identified Polygoni multiflori Radix and Cynanchi Wilfordii radix. The results indicate that the trnL(tRNA-Leu) intron region can be used for inter-specific polymorphic study, and the methods presented in this study can be applied to molecular identification of other medicinal materials.                                    Key words: Polygoni Multiflori radix, Cynanchi Wilfordii radix, Polygonum multiflorum,Cyanchum wilfordii, Cyanchum auriculatum, trnL(tRNA-Leu) intron, polymorphism, multiplex polymerase chain reaction (PCR).