缙云山草珊瑚(Sarcandra glabra)天然居群结实特征的变异性研究

Fruit and Seed Variations of Natural Population of Sarcandra glabra in Mt. Jinyun,Chongqing

对缙云山草珊瑚8个天然居群结实特征的20项表型性状的变异性进行了研究,结果表明:各表型性状在居群内与居群间都存在很大的变异性,其中种实产量、果序数和果序分枝的变异程度较高,而果实和种子的特征指数变异程度较低,同类性状果实的变异程度要大于种子;平均变异系数最大的性状是四分枝果序百分比(1.477),最小的是种子长宽比(0.041);变异程度最大的居群是居群6(0.564),最小的是居群4(0.292);各居群间除果序分枝总数差异不显著、果序数和二分枝果序百分比差异显著外,其它17项表型指标均达到极显著水平,表明缙云山草珊瑚各居群间已经发生了明显的形态分化;居群内和居群间变异分别占总变异的60.7%和39.3%,说明居群内变异是表型变异主要来源,但居群间变异也不容忽视;欧氏距离聚类将所有居群划归为两大类群,主要与居群的群落类型与干扰程度有关;表型性状的Pearson相关性聚类显示草珊瑚同类性状在表型分化过程中具有很强的相关性。

In order to evaluate the phenotypic variation of eight natural populations of Sarcandra glabra in Mt.Jinyun,Chongqing,20 characteristics of fruit and seed were investigated.High levels of variations were revealed in these characteristics among/within populations.Fruit and seed production,number of infructescences and infructescence branches varied to a high degree,while the traits of fruit and seed to a low degree.Compared with fruit traits,the traits of seed seemed more stable.The average variation coefficient of different characteristics ranged from 1.477（percentage of infructescence with four branches） to 0.041（seed aspect ratio）,while the average variation coefficient of populations ranged from 0.564（population 6） to 0.292（population 4）.There was no significant difference in the sum of infructescence branches among populations,significant differences in the number of infructescences as well as the percentage of di-branch infructescences,and very significant differences in all the other characteristics.Variations within populations（60.7%） were the main source of phenotypic variations,and variations among populations（39.3%） influentially contributed as well.Populations of S.glabra in Mt.Jinyun had differentiated into two groups,which were mainly determined by coenotype and disturbance degree.Cluster of phenotypic characteristics based on Pearson correlation showed that similar characteristics highly correlated in differentiation progress and evolution speeds approximated.