Genetic polymorphism and molecular authentication were investigated with the commercial medicinal herb, Peony (Paeonia spp.), using random amplified polymorphic DNA (RAPD) markers. To identify the polymorphism of the RAPD patterns among plant origins, 20 different random primers were applied to the genomic DNA extracted from Paeonia spp. plants such as Paeonia (P.) lactiflora, P. officinale and P. japonica. Ten primers out of 20 primers could be used to discriminate the plant species in the same genus and 72 out of 81 scored DNA fragments (88.9%) generated with these primers were polymorphic. Especially, four primers, such as OPA1, OPA3, OP9, and OPA13, were useful to discriminate the plant origins among the species of Peony. In the results of cluster analysis using RAPD data obtained from the 10 primers, Peony (Paeonia spp.) plants used in this study were grouped into the two distinctive clusters, genetically. Herb medicine, especially P. lactiflora, were easily identified, when species-specific primers were applied to the investigation for discriminating herb medicine currently traded in domestic herb market, Kyungdongmart. Consequently, RAPD analysis was useful method to discriminate plant origins and the commercial medicinal herbs, Paeonia spp..
