我国野牡丹属植物的表型多样性研究

对国产野牡丹属6种16个居群的22个表型性状进行观测,通过方差分析、聚类分析、因子分析对其表型变异、种间亲缘关系等进行探讨,以揭示野牡丹属植物的表型多样性,并为其提供分类依据。结果表明:野牡丹属种间与种内居群间在数量性状上均存在丰富的表型变异,15个数量性状的变异系数为6.77%~34.50%,其中花序花朵数、小苞片宽、叶柄长、花梗长的变异较大,果径、花径、花萼长、花瓣长和叶长宽比的变异较小;质量性状的多样性主要存在于种间,种内居群间在叶柄颜色、花色上存在差异。表型聚类结果显示当平均距离为34时,16个居群可分为3类,展毛野牡丹、多花野牡丹、细叶野牡丹和野牡丹为1类,毛菍、地菍各为1类,同种下各居群没有严格依地理距离聚类。因子分析结果显示,花部形态变异是野牡丹属植物表型分化的主要因素,基出脉、花梗长、茎被毛的变异对其表型分化的作用较小,在进行表型分类时可避免次要性状的干扰。

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.