Identification of the botanical source of stemonae radix based on polymerase chain reaction with specific primers and polymerase chain reaction-restriction fragment length polymorphism.

Stemona sessilifolia, S. japonica and S. tuberosa are the three genuine sources of Stemonae Radix specified in the Chinese Pharmacopoeia (CP) for antitussive and insecticidal remedy. Significant variations in alkaloids composition and content, as well as different degree of antitussive activity were found among them. In order to accurately identify the genuine sources of Stemonae Radix in the genetic level, two polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods were developed based on the sequence differences in chloroplast DNA trnL-trnF and petB-petD regions of the species recorded in CP, as well as S. parviflora and a counterfeit of Stemonae Radix, Asparagus cochinchinensis. By using the restriction enzymes MwoI, AciI and XmnI which were able to recognize specific sequence sites in the trnL-trnF region, and BclI, HincII and BslI which can recognize those in the petB-petD region to digest the corresponding PCR products, the specific digestion pattern enabled the discrimination of the botanical sources of Stemonae Radix effectively and efficiently.