Authentication of Pinellia ternata and its adulterants based on PCR with specific primers.

Tubers of Pinellia ternata are one of the well known traditional Chinese medicines. According to the Chinese Pharmacopoeia, the remedy is commonly used as an antitussive and expectorant. The shapes of young tubers from species of P. ternata are similar to those of P. pedatisecta and Arisaema heterophyllum, but different in medicinal properties. In order to provide molecular evidence for genuine origin identification of P. ternata species, the mannose-binding lectin sequences of P. ternata and its adulterants P. pedatisecta and A. heterophyllum were cloned using genomic walker technology. Based on the sequence analyses, we designed a pair of species-specific primers to authenticate P. ternata. For PCR-selective restriction (PCR-SR), we identified two distinctive sites which can be recognized by the restriction endonucleases BAMHI and NCOI in the open reading frame sequences of P. ternata, P. pedatisecta and A. heterophyllum. Our results indicate that the methods of PCR and PCR-SR are effective, accurate and applicable for identification of the bulbs of P. ternata.