62份紫花风铃木的表型多样性分析

Phenotypic Diversity of 62 Handroanthus impetiginosus Plants

【目的】紫花风铃木(Handroanthus impetiginosus)是我国南方广泛应用的一种园林观赏乔木,其表型性状存在较大的个体差异。通过对紫花风铃木表型多样性进行分析,了解其表型性状差异,可为紫花风铃木优质种质资源发掘和科学育种提供重要理论基础。【方法】以广东省内6个城市12个群体62份紫花风铃木样本为材料,选取20个表型形状对样本进行变异度、Shannon多样性指数、相关性及主成分分析,并基于表型性状进行聚类分析。【结果】紫花风铃木20个表型性状的变异系数为13.53%~59.13%,Shannon指数为0.79~4.08,表型性状变异性和多样性较高,具有丰富的表型性状多样性。相关性分析显示,叶性状相关的数量指标之间相互关联。主成分分析显示,从20个表型性状中提取6个主成分,其中叶宽、叶面积、小叶柄长、叶长、叶柄长等叶性状指标和胸径、枝下高等枝条与树干指标贡献较大。采用Hierarchical法进行表型性状聚类分析可将62份紫花风铃木材料划分为4大类群。【结论】紫花风铃木具有较为丰富的表型变异性和多样性,其中与枝条和树干有关的指标变异系数最高,而叶性状相关指标的多样性较高。主成分分析显示贡献较大的为叶表型性状指标和枝条与树干指标。通过聚类分析可知第II类群中包含的个体花量较大,花色较深;而第I类群中存在开白花的个体,花色比较独特,均具有较好的观赏效果,可从中进一步筛选和繁殖优良品种。

【Objective】A popular ornamental tree for landscaping,Handroanthus impetiginosus tends to differ in phenotypic traits between individual plants.This study aimed to collect information on the resources for selection and cultivation.【Method】Twenty different phenotypic traits of 62 H.impetiginosus plants collected from 12 population groups in 6 cities of Guangdong Province were used to calculate coefficient of variation(CV)and Shannon diversity index as well as conduct correlation,principal component,and clustering analysis.【Result】The CVs of these phenotypic traits varied between 13.53%–59.13%,while the Shannon diversity index between 0.79–4.08.High CV and diversity index connotated richness in phenotype diversity of the species.Their qualitative indices differentiated more greatly than quantitative ones,and the qualitative indices correlated with one another.Among the 6 principal components in the 20 traits,the indices associated with leaf,including width,area,length,petiolule length,and petiole length,were the major contributors which were followed by those related to the branch and trunk diameters at breast height and under branch height.A hierarchical clustering analysis divided the 62 H.impetiginosus plants into 4 population groups based on their phenotypic characteristics.【Conclusion】H.impetiginosus was richly diverse phenotypically.The indices related to branch and trunk ranked highest on CV,while those associated with leaf greatest on diversity index.The principal components of the traits,such as leaf-,branch-,and trunk-related indices,largely determined the phenotype of H.impetiginosus plants.The population Group II plants as classified by the cluster analysis had more dark color flowers,whereas Group I carried distinctive,attractive white blossoms that were valued generally for landscaping,cultivation,and breeding purposes.