Allele-specific diagnostic PCR authentication of Dendrobium thyrsiflorum

The aim of this study was to establish a diagnostic PCR method for authentication of D.thyrsiflorum Rchb. f. Based on rDNA ITS sequences of the 164 samples from 109 Dendrobium species sequenced and quoted from GenBank, the allele-specific diagnostic primers QH-JB1 and QH-JB2 for authentication were designed. Using the primers, diagnostic PCR was performed with the total DNA of D.thyrsiflorum Rchb. f. and other D. species as templates to establish the positive PCR condition for D.thyrsiflorum Rchb. f. A DNA fragment about 300 bp was amplified from D.thyrsiflorum Rchb. f. with anneal temperature at 63.5 ℃ and anneal time at 1 min, whereas no other DNA fragment was amplified from the rest D. species. The allele-specific diagnostic PCR was proved to be a simple and quick identification technique, suitable for the authentication of both fresh and dried materials of D.thyrsiflorum Rchb. f.