濒危植物夏蜡梅花的形态变异

Morphological Variation of Flowers in Endangered Plant Sinocalycanthus chinensis

研究了不同地理位置的3个夏蜡梅自然种群间以及种群内花部形态变异,并对3个种群进行聚类分析。结果表明:夏蜡梅花部表型性状在种群间和种群内都存在一定程度的变异;各性状总的平均变异系数在6.293(内瓣长)～46.90(花柄长)之间,种群间总的平均变异系数在13.430(DMS)～15.7208(DLS),因此认为夏蜡梅花的表型性状无论是在物种水平还是在种群水平都具有较丰富的表型多样性,其中又以大雷山种群最高;单因素方差分析显示:部分指标分化显著或极显著,13个指标在种群内的变异占了总变异的82.9%,这说明夏蜡梅种群内变异是表型变异的主要来源,由此可以推测遗传上的多样性是形成夏蜡梅花部形态变异的主导因素;种群间平均变异组分占了17.1%,表明花部形态在种群间存在一定程度的表型分化;聚类分析显示距离较近的大明山种群和龙须山种群先聚在一起,表型差异与地理距离之间存在显著正相关,经分析认为微生境的异质性和种群隔离以及遗传漂变均可能导致夏蜡梅种群间的表型分化;相关性分析显示部分性状之间存在显著的相关性。

Morphological variation of flowers in Sinocalycanthus chinensis were investigated among natural populations and within the population in three different regions. Cluster analysis was used to cluster these three populations. Results indicated that the morphological characteristics of flowers had certain variation both within and among populations of S.chinensis. The average coefficient of variation of each characteristic of flowers ranged from 6.293（Inner-petal length）~46.90（Flower stalk length）,while among populations ranged from 13.430（DMS）~15.7208（DLS）. Morphological diversities of flowers were high at both species level and population level. In these three populations,DLS population was the highest. One way analysis of variance （ANOVA） showed significant differences existed in parts of flower traits,from which over 82.9% of the variance was attributed to the differences within population,it put forward that genetic diversity was the dominant factor of morphological variation of flowers. 17.1% of the variance existed among populations which meant that certain phenotypic differentiations existed among populations. Cluster analysis revealed DMS population and LXS population between which have the nearest distance were clustered into one group. There was a significant positive correlation between morphologal variation of flowers and geographic distance. After analysis it can be concluded that heterogeneity of micro-habitat,population isolation and genetic drift can lead to phenotypic differentiation of flowers in S.chinensis. Correlation analysis showed significant correlation within parts of flower traits.