玉叶金花属（茜草科）植物DNA条形码研究

his study aims to develop fast and accurate species identification methods for Mussaenda L. (Rubiaceae). Methods In the present study, DNA barcoding analysis was carried out on a total of 89 individuals representing 20 species of the genus Mussaenda in order to evaluate the performance of the four candidate barcoding loci (matK, rbcL , trnH-psbA and ITS). Methods of sequence similarity and Neighbor-joining tree were applied. Inter- and intra-specific genetic distances were detected based on Kimura 2-parameter (K2P). Inter-specific genetic distance was significantly higher than intra-specific genetic distance. Comparably high species discrimination power was revealed by the matK and ITS data set. The candidate barcode of rbcL displayed the lowest identification rate among the others. However, each individual candidate barcode demonstrated significantly lower discrimination power than the barcode of combined data set. Comparable discrimination power was revealed between the two barcodes of combined sequences matK+rbcL+ITS and matK+rbcL+trnH-psbA+ITS, which showed the values around 77% and 75% based on sequence similarity and Neighbor-joining tree method. Totally 15 species were identified based on Neighbor-joining analysis of matK+rbcL+ITS. Consequently, the combined sequences of matK+rbcL+ITS provide an effective and fast tool for identification and authentication of medicinal plants species in the genus Mussaenda. ?????