Molecular authentication of Panax ginseng and ginseng products using robust SNP markers in ribosomal external transcribed spacer region

Panax ginseng and Panax quinquefolius are the most widely used Panax species, but they are known to have different properties and medicinal values. The aim of this study is to develop a robust and accurate DNA marker for identifying P. ginseng and the origins of ginseng products. Two single nucleotide polymorphism (SNP) sites specific to P. ginseng were exploited from nuclear ribosomal external transcribed spacer (ETS) region. Based on the SNP sites, two specific primers were designed for P. ginseng and P. quinquefolius respectively. P. ginseng can be easily discriminated from P. quinquefolius by amplifying the two specific alleles using multiplex allele-specific PCR. Favorable results can also be obtained from commercial ginseng products. The established method is highly sensitive and can detect 1% of intentional adulteration of P. quinquefolius into P. ginseng down to the 0.1 ng level of total DNA. Therefore this study provides a reliable and simple DNA method for authentication of the origins and purities of ginseng products.