杂交桉家系在粤北山地的生长表现与优树选择

Growth performance and tree selection of Eucalyptus hybrid families at three time points in northern Guangdong

【目的】比较3个时间节点桉杂种亲本特点和评价子代生长及形质指标的变化,选择不同时间节点的优良家系/单株。【方法】利用方差分析、相关分析和家系/单株坐标综合法,分析连山林场测定林112杂种家系和2个对照无性系在3个时间节点的性状变化,评价树种、家系及单株的性状变化及差异。【结果】各个节点不同性状在杂种家系、家系与区组交互效应间均存在极显著差异;以11年生平均单株蓄积加1或2倍标准差为选择指标筛选生长优良家系,分别20个和3个家系入选,入选家系与5年生时不同;不同林龄生长性状存在相关关系,干形与生长性状均存在极显著相关,早期耐寒性与3年生生长存在极显著相关;以11年生生长和形质指标进行坐标综合法家系分类,优、中和差各有22、68和22个家系入选,其中22个优良家系中以尾叶桉、邓恩桉和巨桉为母本分别有14、5和3个家系,优良家系以巨桉和赤桉为父本分别8和4个;杂种家系单株选择中小于DH3229最优单株得分值(0.2032)的共有46株,其中54号尾巨桉家系有3株入选,另有9个家系各有2株入选,入选46株优树分属10个家系,其中7个家系属于巨桉子代。【结论】通过性状选择可以获得不同时间节点下的优良家系/单株;不同家系生长存在早晚快慢差异,11年生生长最优家系60号尾巨赤、42号尾巨桉和95号邓巨桉家系,适合开发胶合板材无性系,5年生选择的优良家系适合开发纸浆材无性系;尾叶桉和邓恩桉为母本、巨桉和赤桉为父本的杂交子代易选择到形质和生长优良的家系;该立地巨桉亲本是值得关注的优良桉树,适合持续开发优良无性系和推广应用。

【Objective】This work was designed to compare the characteristics of Eucalyptus parents and evaluate the growth variation and morphological traits of progenies at 3 time points,to select the superior family/individual.【Method】Using the methods of variance analysis,correlation analysis and coordinate assessment,the trait changes of 112 hybrid families and 2 control clones were analyzed,and the changes and differences among species/families/individuals were evaluated at three different time points in Lianshan Forestry Farm.【Result】The results showed that there were significant differences among hybrid families at 3 time points and the interaction between families and blocks.The average stock volume per plant at the age of 11 plus 1 or 2 times STDEV was used as the selection index for superior families.Base on that,20 and 3 families were selected,respectively,which were different from those at 5 years old.There was a significant correlation between growth traits at different ages.There was a significant correlation between trunk shape and growth traits,and there was a significant correlation between cold tolerance and the 3-year growth.According to the Coordinate Assessment score of the growth and morphological levels at the age of 11,22,68 and 22 families were selected as good,medium and poor types,respectively.Among the 22 excellent families,there were 14,5 and 3 maternal families of Eucalyptus urophylla,Eucalyptus dunnii and Eucalyptus grandis,respectively,and 8 and 4 paternal families of Eucalyptus grandis and Eucalyptus camaldulensis,respectively.【Conclusion】The excellent families/individuals at different time points could be obtained by character selection.There is a difference in the growth rate of different families.The best 11-year-old families(No.60,No.42 and No.95)are suitable for the development of glued board clones.and the best 5-year-old families are suitable for the development of pulp wood clones.The superior family can be easily obtained from the hybrid offspring when Eucalyptus urophylla and Eucalyptus dunnii are used as the female parent and Eucalyptus grandis and Eucalyptus camaldulensis are used as the male parent.The results showed that the parents of E.grandis deserve attention and are suitable for the continuous development and application of excellent clones.