The Systematic Study On Chinese Species Of Genus Melastoma

Melastoma is a genus of family Melastomataceae. In the previous research, there are 9 species of Genus Melastoma in China. In the recently published<Flora of China>, only 5 species of genus Melastoma are recognized. The species of this genus are dealt with as follows:M. penicillatum is merged into M. sanguineum; M. dendrisetosum is used as a synonym of M. sanguineum, and it is not recognized as a species; M. normale and M. affine are merged into Melastoma malabathricum. In this study, aiming at the controversy of the taxonomy in Chinese native species of Melastoma, by means of molecular phylogeny, combining with the morphology characteristics of genus Melastoma, a comprehensive study and discussion on Chinese species of genus Melastoma was conducted. The main results of the study as follows:1. In the molecular phylogeny study of genus Melastoma,23 pairs of primers for 21 gene fragments were screened, and the annealing temperature of the primers was optimized. The PCR amplification reaction system was optimized by orthogonal design.21 gene fragments were amplified successfully by the optimized PCR reaction conditions. After the analysis of the sequences, three gene sequences:cp-ndhF, mt-matR and nr-ETS, which had more information sites, were used to construct molecular phylogenetic trees by Maximum Parsimony and Bayesian Inference. The results of the molecular phylogeny study showed that, Melastoma were clustered into one clade, and it was a monophyletic group. The research result of molecular phylogeny could resolve the phylogenetic relationship between genus and genus of family Melastomaceae. In genus Melastoma, M. dodecandrum was divided into a separate clade, and there was a far phylogenetic relationship between M. dodecandrum and the other species of genus Melastoma; M. intermedium was divided into a separate clade, and there was a far phylogenetic relationship between M. intermedium and the other species of genus Melastoma.2. In the morphological characteristics:There were obvious differences in the morphology characteristics of the flowers, hair, fruits, branches and leaves of M. penicillatum, M. dendrisetosum and M. sanguineum.3. Combining the research result of molecular biology evidence and morphological characteristics of genus Melastoma, the research makes a conclusion that:It do not support that M. dendrisetosum as a synonym of M. sanguineum. It do not support that M. penicillatum is merged into M. sanguineum. Each species of them should be treated as an independent species. The controversy of the taxonomic of M. normale, M. candidum and M. affine should be further studied.