大叶榉树无性系生长性状的早期变异

该文报道了大叶榉树无性系2年生幼林生长测定结果。研究表明,不同无性系树高、胸径、枝下高、冠幅、干形、分枝数、分枝粗、分枝角度等8个性状均有显著差异(P0.05),不同性状的遗传变异系数在4.7%~26.6%之间,性状重复力在0.49~0.89之间。胸径与树高、枝下高之间,冠幅与分枝角度、干形(弯曲度)之间存在显著正相关,树高与分枝粗度之间存在显著的负相关。主成分分析结果显示,无性系性状前4个主成分的贡献率达85.21%,利用主成分得分值进行聚类分析,可将24个无性系划分为4类。以用材为育种目标,初选出"红4"、"桔3"和"黄10"等3个优良无性系。

Variation in growth traits of Zelkova schneideriana clones at juvenile stage

In this study, variation in growth traits of 2-year-old Zelkova schneideriana clones was studied. It showed that there were significant differences in the tree height, diameter at breast height （DBH）, clear bole height, crown width, stem form, branch number and coarseness, and branching angle among different clones （P 〈 0.05）. The genetic coeffi- cients of variation in different traits were 4.7% -26.6% , and the repeatability of different traits was 0.49 -0.89. There was significant positive correlation between DBH, tree height and clear bole height. And crown width was positively correla- ted with stem form and branching angle. Whereas, significant negative correlation was found between tree height and branch coarseness. PCA showed that the contribution ratio of the first four traits of clones reached 85.21%. Moreover, the 24 clones were divided into four groups by cluster analysis with the scores of principal components. Using fast-growing timber as breeding objective 3 superior clones had been selected, which were ＂Red 4＂ ,＂ Orange 3＂ and ＂Yellow 10＂.