红锥1.5代改良种子园无性系生长和形质性状变异分析

Analysis on Variation of Clonal Growth and Form Traits for 1.5 Generation Improved Seed Orchard of Castanopsis hystrix

对红锥（Castanopsis hystrix）1.5代改良种子园42个无性系共951个单株的生长和形质性状进行调查和变异规律研究。结果表明,8个性状的变异系数为25%~47%,平均变异系数为32.6%。无性系间在生长和形质性状上的差异达显著和极显著水平（P〈0.05）,无性系间的方差分量为0.04~13.15。树高、胸径、冠幅、分枝角度、分枝数和分枝粗细的重复力介于0.23~0.34之间,表明它们在单株水平上受到中等水平的遗传控制。生长和形质性状相关分析表明,除通直度与冠幅、分枝数相关系数以及分枝粗细与分枝角度相关系数较低外,各性状间存在着不同程度的相关性。采用遗传值综合评分法筛选出6个优良无性系：28、3、4、23、33和22,这6个优良无性系的胸径比42个无性系总体平均值高出24.11%。

The growth and form traits of 951 plants from 42 clones of Castanopsis hystrix in 1.5 generation improved clonal seed orchard were investigated, and the genetic variation was analyzed based on the data. The results indicated that the variation coefficients of the traits ranged from 25.0% to 47.0%, and average variation coefficient was 32.6%. Growth and form traits had significant differences（P〈0.05）, and variance component ranged from 0.04 to 13.15. The repeatability of height, diameter at breast height（DBH）, crown width, branch angle, branch number and branch size ranged from 0.23 to 0.34, indicating that the traits of clones were genetic controlled at the medium level. The genetic correlation coefficient of growth and form traits showed that they had strong positive genetic correlation except for stem straightness and crown width, stem straightness and branch number, branch size and branch angle. The six excellent clones of No 3, 23, 33, 4, 28 and 22 were selected based on an integrated scoring method of breeding value from ranking, and the DBH of six clones was 24.11% higher than that of the 42 clones that provide a basis of further selection and extension of superior clones.