Specific PCR Identification between and and Identification between Them and Adulterant Using DNA Barcode.

Background: The traditional Chinese medicine (TCM) Qianhu and Zihuaqianhu are the dried roots of and , respectively. Since the plant sources of Qianhu and Zihuaqianhu are more complex, the chemical compositions of and are significantly different, and many adulterants exist because of the differences in traditional understanding and medication habits. Therefore, the rapid and accurate identification methods are required.

Objective: The aim was to study the feasibility of using DNA barcoding to distinguish between Traditional Chinese medicine Qianhu (), Zihuaqianhu (), and common adulterants, based on internal transcribed spacer (ITS) sequences, as well as specific PCR identification between and .

Materials And Methods: The ITS sequences of , , and adulterant were studied, and a phylogenetic tree was constructed. Based on the ITS barcode, the specific PCR primer pairs QH-CP19s/QH-CP19a and ZHQH-CP3s/ZHQH-CP3a were designed for and , respectively. The amplification conditions were optimized, and specific PCR products were obtained.

Results: The results showed that the phylogenetic trees constructed using the BI and MP methods were consistent, and and sequence haplotypes formed their own monophyly. The experimental results showed that in PCR products, the target bands appeared in the genuine drug and not in the adulterant, which suggests the high specificity of the two primer pairs.

Conclusion: The ITS sequence was ideal DNA barcode to identify , , and adulterant. The specific PCR is a quick and effective method to distinguish between and .

Summary: and sequence haplotypes formed their own monophyly.The ITS sequence was ideal DNA barcode to identify , , and adulterant.Specific PCR is a quick and effective method to distinguish between and . TCM: The traditional Chinese medicine, , , ITS: The internal transcribed spacer, PCR: Polymerase chain reaction, NCBI: National Center for Biotechnology Information, NI: Number of individuals, HN: Haplotype number; GAN: Gen Bank accession numbers, , , , , BI: Bayesian inference, MP: Maximum parsimony, AIC: Akaike Information Criterion, MCMC: Markov Chains Monte Carlo, TBR: Tree bisection-reconnection, LPP: Length of PCR product, PRP: PCR reaction procedure, SNP: Single nucleotide polymorphisms, PP: Posterior probability, BS: Bootstrap.Qun Zhao.