7年生短枝木麻黄优良无性系选择的研究

以海南2个试验点上各含17个无性系的短枝木麻黄无性系为试验材料,进行树高、胸径、单株材积、主干分叉习性、主干通直度和保存率等6个性状的方差分析,并估算出6个性状的遗传相关和遗传力及指数选择等遗传参数。结果表明:无性系和地点的交互作用除了主干分叉习性有显著差异(p0.05)外,其他性状在无性系间差异均极显著(p0.001)。当不考虑无性系和地点互作时,无性系间不同性状的重复力均较高,为0.35 0.85,其中,树高重复力最高,主干分叉习性最低。遗传相关分析结果表明:树高、胸径、单株材积和保存率之间的表型及遗传存在极显著的正相关。树高、胸径、单株材积、主干分叉习性、主干通直度和保存率的平均遗传增益分别为6.5%、4.8%、10.9%、3.7%、1.5%和8.1%,筛选可获得明显的遗传增益。通过Smith-Hazel指数选择并按20%的入选率,选育出编号17、21和20三个优良无性系。

Superior Clone Selection of Casuarina equisetifolia

17 casuarina clones grown in two sites in Hainan, viz. Daodong Forest Farm and Wenchang Forest Institute, were assessed for tree height, diameter at breast height, individual volume, axis persistence, stem straightness and survival percentage.The result indicated that genetic variations of those 6 traits were significant differences (p<0.05 or p<0.001) not only in tree growth indexes at each site but also genotype and site interaction among 17 clones. Meanwhile, the repeatability varied from 0.35 (axis persistence) to 0.85 (height). The genetic correlation was analyzed as well, it was showed that the height, diameter at breast height, individual volume and survival percentage had highly significant correlation. In addition, the mean genetic gains in height, diameter at breast height, individual volume, axis persistence, stem straightness and the survival percentage were 6.5%, 4.8%, 10.9%, 3.7%, 1.5% and 8.1% respectively. Three superior clones were selected from the 17 clones.