赤桉第二代家系遗传变异及早期选择研究

Genetic variation and early selection of second generation breeding population of Eucalyptus camaldulensis

对广西国有东门林场2.5年生赤桉第二代家系试验林进行生长性状分析与遗传评估,探讨赤桉家系遗传变异规律,旨在选择遗传增益较高的优良家系和优良单株。结果表明:参试90个家系间胸径、树高、材积存在极显著差异;胸径、树高、材积的家系遗传力及单株遗传力均大于0.5,表明在家系和单株水平上均受强度遗传控制;以胸径、树高、材积3个主要生长性状构建赤桉家系/单株选择指数方程,按照标准选择出5个优良家系,选择率为5.6%;选择出65株优良单株,选择率为2.7%,优良单株平均胸径、树高、材积遗传增益分别达44.34%、35.64%、142.90%,选择效果明显。

Several statistical methods were applied in this study to analyze Eucalyptus camaldulensis provenance growth properties and heredity as well as genetic variation law in Guangxi Dongmen state-owned forest farm based on 2.5-year-old Eucalyptus camaldulensis provenance testing plantation, The purpose is to select out genetic gain higher good pedigree and superior individual. Results showed that significant differences exist in DBH, H and V of 90 Eucalyptus camaldulensis provenance. Heritability of D, H, V and individual tree was was greater than 0.5 indicating genetic factors control these traits in provenance and individual level. Index equations of provenances and individuals were built based on D, height and volume, 5 superior provenance with a selection rate of 5.6% and 65 superior individuals with a selection rate of 2.7% were selected according to criterion. Genetic gain of superior individuals＇ mean DBH, H and V reached 44.34%, 35.64% and 142.90%, demonstrating distinct selection effect.