Phenotypic Diversity of Melastoma L.in China
In order to reveal the phenotypic diversity of Melastoma L.and provide classification evidence,twenty-two phenotypic traits of six species and sixteen populations of Melastoma L.in China were investigated.Phenotypic variations between and within species as well as phylogenetic relationship between species were discussed by using variance analysis,cluster analysis and factor analysis.The results showed that there were rich phenotypic variations between and within species of Melastoma L.in quantitative traits.The variation coefficients of 15 quantitative traits ranged from 6.77% to 34.50%.Among these traits,flower number of inflorescence,bractlet width,petiole length and stalk length varied more while fruit diameter,flower diameter,calyx length,petal length and length-width ratio of leaf varied less.The diversity of qualitative traits mainly existed between species,and colors of petiole and flower also varied in populations.According to cluster analysis by twenty-two phenotypic traits,16 populations of Melstoma L.could be roughly divided into three groups when the average distance was about 34.Besides M.normale,M.affine,M.intermedium and M.candidum gathering in one group,M.sanguineum and M.dodecandrum was divided into two groups respectively.Populations within species did not clustered strictly by geographical distances.Factor analysis indicated that floral morphological variations might be the main causes of phenotypic differentiation in Melastoma L.,on which the variations of basal vein,stalk length and pubescence on stem effected lightly.Therefore,some secondary phenotypic traits of Melastoma L.could be paid little attention in morphological classification.