18年生巨桉半同胞子代测定林遗传分析与选择

对代表全分布区的29个地理种源包含147个家系的18年生巨桉子代测定林的生长性状进行观测和遗传分析。结果表明:除树高以外,其他性状在种源和家系间均呈极显著差异(P0.01),其中:树高家系遗传力为0.879 7,树高单株家系遗传力为0.296 2;胸径家系遗传力为0.943 4,胸径家系单株遗传力为0.662 9;材积家系遗传力为0.950 9,材积单株家系遗传力为0.747 2。通过生长性状的多重比较并结合早期纤维密度的分析结果,筛选出15个速生优良家系,其平均家系材积遗传增益67.9%;在家系选择基础上选出速生优良单株13株,其平均单株立木材积遗传增益172.2%,选出的优良家系及单株将来可以用作营建巨桉实生种子园和杂交育种的亲本材料。

Genetic Analyses and Genotypic Selection from an 18 Years Old Half-sib Progeny Trial of Eucalyptus grandis

A provenance-family trial of Eucalyptus grandis was established in Fujian,China,in 1990 using seeds provided by the Australian Tree Seed Centre of 147 open-pollinated families representing 29 natural stand provenances from across the entire natural range of the species. Highly significant (P<0.01) differences in growth characteristics were found among both provenances and families-within-provenances at age 18 years. Family and individual heritabilities estimated for tree height were 0.879 7 and 0.296 2 respectively, those for DHB were 0.943 4 and 0.662 9 respectively, and those for volume were 0.950 9 and 0.747 2 respectively. Using comparisons of multiple growth traits combined with early age wood density, 15 superior families and 9 superior individuals were selected. Average volume genetic gain with these superior families and individuals was 67.9% and 172.2% respectively, and these selected families and individuals should provide high quality genotypes for ongoing breeding.