Identification of Melastoma dodecandrum and Confusable Species by DNA Barcoding

A total of 95 ITS2 sequences were obtained from 95 samples of Melastoma dodecandrum and confusable species like M. affine, M. candidum, M. normale, M. sanguineum, Blastus pauciflorus, Phyllagathis cavaleriei, Bredua amoena collected from Zhejiang, Jiangxi, Fujian and Guangxi provinces. And 30 ITS2 sequences of corresponding species were downloaded from GenBank. Sequence characteristics such as length, GC contents, and variable sites were analyzed by Gene Tool software while genetic distance calculation and neighbor-joining （NJ） phylogenetic tree was built by Clustal X and MEGA 7.0. The result demonstrated that the length of ITS2 sequences of M. dodecandrum and confusable species ranged from 224 to 236 bp with GC content of 60.6%-69.2%. The intra-specific K2P genetic distance of M. dodecandrum was significantly lower than that among the other seven confusable species. It was obvious that the ITS2 sequences of M. dodecandrum formed into one separate clade in the phylogenetic tree, while the other seven confusable species clustered into other clades.