邓恩桉优良种源及其家系与优株选择研究

收集邓恩桉全天然分布区种源及其家系进行引种试验,以酷热严寒等极端天气的抗逆性表现,评估其对气候的适应性;采取多点试验联合分析法,回归分析各处理所有地区的生长信息,评估其对不同立地环境的适应性,建立起各种源、家系的生长模型。各种源性状优良,种源间差异不显著,整个天然分布区均为优良种源区;选出最佳种源地12个;优良家系46个,平均34.16 m3·hm-2·yr-1,径高比≥1：90、个体变异≤15%,木材材质好、造纸得浆率49%;家系间差异极显著,优良家系的遗传增益显著大于最佳种源;选优良单株250株,其中68株3年生时始花。区组间差异极显著,大多数种源、家系与地区的交互作用极显著,回归系数大,对生长环境敏感,要有好的立地条件才能发挥其速生特性。

Selection of Excellent Provenances,Families and Individual Plus-Trees of Eucalyptus dunnii

A range of Eucalyptus dunnii provenances and families were collected from this species natural distribution in order to evaluate their adaptation and growth in Hunan province, especially in relation to the province＇s climate featuring very hot summers and cold winters. By joint analysis and regression analysis of the tree growth, we evaluated the adaptability of E. dunnii to the different sites and developed a growth model for different provenances and families. Variation among provenances proved to be insignificant and all provenances from the natural distribution performed well. In contrast, there was significant variation among the families tested. The top 12 provenances and best 46 families were selected. Average productivity was 34.16 m3·hm-2·yr-1, the ratio of diameter to height was great than 1：90 and the variation among individuals was less than 15%. Wood properties were found to be well suited to a range of end-uses and kraft pulp yield exceeded 49%. The genetic gain of the good families was bigger than that of the best provenances. of 250 E. dunnii individual plus-trees selected from the material tested, 68 trees started to flower from age 3-years. Strong correlations were found between growth and site conditions, for most provenances and families. In order to realize the species potential for fast-growth and high productivity, E. dunnii needs be provided with good sites.