云南保存橡胶树部分种质资源干形及分枝变异分析

Phenotypic Variation of Stem Form and Branching Structure from Hevea brasiliensis Germplasm Resources in Yunnan Province

对保存于“农业部景洪橡胶树种质资源圃”的1904份橡胶树81’IRRDB种质资源的主干通直度、主干分杈、侧枝分枝轮、侧枝粗细、侧枝分枝角、侧枝伸展等6个表型性状进行调查和分析。结果表明,云南保存橡胶树种质资源具有丰富的遗传多样性（0.2604～1.6731）,多样性指数最高的是主干通直度,达1.6731,其次是主干分杈、侧枝粗细、侧枝分枝轮和侧枝分枝角,最低的是侧枝伸展。6个表型性状的相对分布频率最小值为2.92%～8.05%,最大值为41.26%～93.37%。用UPGMA法聚类,当欧式距离为1.05时,1904份样本被聚为5组,其中最大1组包括98.42%的样本,表明同一性状在每份种质资源间具有很大程度的相似性；用Furthest Neighbor法聚类,在欧式距离为1.45时,1904份样本被聚为7组。2种聚类方法都能将每份种质明显区分出来,表明各性状变异极其丰富。

An investigation was carried out to study the variation of 6 phenotypic traits of stem form and branching structure from 1904 accessions of Hevea brasiliensis germplasm conserved in Jinghong,Yunnan Province. The results showed that there were abound ant genetic diversity in Hevea brasiliensis germplasm conserved in Jinghong（ 0. 2604-1. 6731）. The diversity of stem straightness was the highest,than stem devergence,branch diameter, branch whorl,and branch angle,while branch extension was the lowest. The minimum value of distribution frequency of relative traits ranged from 2. 92% to 8. 05%,and the maximum from 41. 26% to 93. 37% among the 6 traits. Based on the Euclidean distance,1904 accessions germplasm were divided into 5 groups at 1. 05 thresholds by UPGMA and divided into 7 groups at 1. 45 thresholds by furthest-neighbor cluster analysis. Abundant phenotypic variation existed in the populations of germplasm resources.