[Study on identification of Dendrobium officinale and related species by bidirectional PCR amplification of mismatched and specific alleles].

Based on rDNA ITS sequences of Dendrobium officinale and the other 69 species of Dendrobium, a pair of dismatched allele-specific diagnostic primers, TPSH-AS1F and TPSH-AS1R were designed to authenticate D. officinale from the other species. Thebidirectional PCR amplification were performed using the diagnostic primers with the total DNAs of the original plants or processing products as a template. When the annealing temperature was raised to 60 ℃, only the template DNA of D. officinale could be amplified whereas the diagnostic PCRs of the other Dendrobium species were all negative. Compared with the other authentification methods, the bidirectional PCR amplifications is not only simpler and time-saving but practical and effective.