PsbA-trnH, an Ideal DNA Barcode for Species Discrimination in Folk Medicine Rodgersiae Rhizoma (Saxifragaceae)

DNA barcoding is a beneficial molecular tool used widely in species identification and discrimi-nation based on species-specific differences by means of standardized DNA markers. The plastid (psbA-trnH, matK and rbcL), and nuclear ribosomal internal transcribed spacer (ITS and ITS2) regions were employed for the differentiation of three kinds of Rodgersiae rhizoma, namely Rodgersia pinnata Franch, Rodgersia aesculifolia Batalin and Rodgersia sambucifolia Hemsl, respectively. DNAs extracted from the three studied species were amplified by polymerase chain reaction (PCR) using universal primers, and all the amplified samples were then sequenced. Phylogenetic analyses were constructed for three kinds of Rodgersiae rhizoma, and the monophyly of Rodgersiae rhizoma was well supported by psbA-trnH marker. These three varieties of Rodgersiae rhizoma could be clustered into three groups with the help of neighbor joining tree, which was in accordance with their germplasm origins. Therefore, psbA-trnH sequence was an ideal DNA barcode in Rodg-ersiae rhizoma species. DNA barcoding can be regarded as a powerful complementary approach for tradition-al authentication, especially for those varieties that are difficult to be differentiated by conventional method.