核桃壳厚度表型变异及其与重要农艺性状间相关分析

为探讨壳厚度在群体水平上的表型变异,将其应用于核桃育种,以66个核桃品种为试材,对包括壳厚度在内的9个性状进行相关回归分析,采用聚类分析及主成分分析的方法分析群体结构效应对壳厚度表型变异的影响。核桃壳厚度在群体水平上变异范围为0.60～1.50,变异系数最大,为0.21;壳厚度与出仁率在P=0.01水平上显著负相关,相关系数为-0.61,与其他性状不相关;聚类分析和主成分分析显示4个亚群(pop-population)可以解释该群体(Q,population)的群体结构;前3个主成分可以解释总表型变异的77%。研究结果可以为薄壳核桃新品种选育提供理论参考。

Phenotypic Variation of Juglans regia Shell Thickness and Its Application in Variety Breeding

To investigate the shell thickness phenotypic variation and its application in walnut breeding, nine biological traits including vertical diameter, transverse diameter, lateral diameter, fruit mass, kernel mass, kernel rate, fatty acid content, protein content and shell thickness were collected, and their correlations were analyzed. Cluster analysis and principal component analysis (PCA) were adopted to study the population structure effects on the phenotypic variation of shell thickness in walnut. Among 66 walnut varieties, the variable coefficient of the shell thickness ranged from 0.60 to 1.50, and enjoyed the maximum variable coefficient of 0.21 among all traits. Correlation analysis indicated that the shell thickness was negatively correlated to kernel rate with r=-0.61 (P=0.01). The population was divided into four pop-populations (Q1, Q2, Q3 and Q4) with 42, 18, 5 and 1 in Q1, Q2, Q3 and Q4, respectively. The principal component analysis of 66 accessions based on the nine traits indicated that the first three principal components (PC1, PC2 and PC3) could explain 77% of the total phenotypic variation. The results can provide a theoretical guidance for paper shell cultivar breeding.