Polymorphism analysis of TCP gene region to intraspecific analysis of Paeonia lactiflora, and application for authentication of Paeoniae Radix.

We attempted to conduct an intraspecific analysis of 30 peony cultivars in Japan and to authenticate five herbal medicine samples derived from Paeoniae Radix by polymorphism analysis of the TEOSINTE BRANCHED1, CYCLOIDEA, and PCF (TCP) gene region. We focused on cultivar-dependent differences in leaf margin undulation and analyzed the sequence of the related TCP gene region. As a result, we found that the nucleotide sequences of 29 cultivars of Paeonia lactiflora except 'America' exhibit interspecific variations compared with the nucleotide sequences of Paeonia suffruticosa and Paeonia tenuifolia. Therefore, in the dendrogram constructed on the basis of the sequence similarity in the TCP gene region, the 29 cultivars of P. lactiflora were separated from P. suffruticosa, P. tenuifolia, and 'America', and clustered into three subgroups. There were 16 variations containing heterogenous DNA sequences within P. lactiflora species, and two characteristic variations in subgroup I. Some P. lactiflora cultivars showed the same nucleotide sequence in the TCP gene region, whereas the five herbal medicine samples showed different sequences, although all of them could be authenticated. The results suggest that Paeoniae Radix in the Japanese crude drug market can be authenticated by analysis of the TCP gene region.