杂交桉家系在桂北生长及优良性评价

【目的】对广西黄冕林场杂交桉的生长及优良性进行评价,找到更多适合在该区域今后推广种植的优良杂种材料。【方法】对3.5、5.8和8.5 a共3个年度的42个人工杂种家系、9个母本自由授粉家系和1个无性系试验林进行生长调查,开展不同林龄的干形、幼林枝瘿姬小蜂的受害率等的调查,利用方差分析和多性状综合坐标得分法进行分析,获得综合表现优良的杂种子代及单株。【结果】不同林龄的树高在早期生长、胸径和单株蓄积在所有年度的杂种家系间均存在极显著差异。以8.5 a最优47号尾叶桉自由授粉家系的单株蓄积0.346 1m3为标准,6个人工杂种家系包括20、39、36、28、14和18号家系高于其值而表现出杂种优势,其值范围为0.346 3~0.479 8 m3;以对照无性系DH32-29的8.5 a单株蓄积0.288 0 m3为标准,则有20个家系高于对照,其值范围为0.291 8~0.479 8 m3。采用综合坐标法平均得分值±1个标准差(得分0.037 4和0.144 4)为指标筛选家系,则有7个、39个和6个家系分别归于适生型、中生型和淘汰型3类家系。按适生型家系7/51入选率,家系遗传增益值在1.69%~21.36%范围,单株遗传增益在1.37%~19.70%,按优于对照无性系得分值15/51入选率下,家系遗传增益值在1.13%~14.74%,单株遗传增益在0.91%~13.60%。【结论】按最优对照单株得分值0.085 8为标准,共有27个家系的48株优株入选,入选单株最多的3个家系均为尾巨杂交桉,表明尾巨桉适应桂北立地,在该区域推广时可优先选择。

Study on the grouped and genetic analysis of Eucalyptus hybrids in northern Guangxi

【Objective】With the help of the evaluation of the growth and fine quality of hybrid Eucalyptus in Huangmian forest farm,Guangxi province,more excellent hybrid materials suitable for future planting in this area were found.【Method】The growth,stem form and rate of wasp damage data of traits at 3.5,5.8 and 8.5 a had been analyzed including of 42 artificial-hybrided progeny,9 natural pollination families and 1 clone in trials by variance and coordinate assessment method,and at last the superior progeny families and plus trees had been selected.【Result】There were significant differences between height,DBH and single volume at three different ages.Based on the 0.3461 m3 single volume of the superior No.47 Eucalyptus urophylla families with free pollination at 8.5a,6 artificial hybrid families including 20,39,36,28,14 and 18 families showed heterosis,and their single volume value was 0.3463-0.4798m3;Based on the 0.2880 m3 single volume of control clone DH32-29 at 8.5 a,there are SV values of 20 families to exceed the control’s DH32-29.According to the method of coordinate assessment with 0.0374-0.1444 standard value,there are 7,39 and 6 families,which belong to 3 different types including of the adaptive,mean and eliminate type according to the family adaptability in trial area.The family gain of traits in terms of 7/51 selection ratio were estimated to be 1.69%-21.36%,The tree gain in family were estimated to be 1.37%-19.70%.【Conclusion】There are 48 plus trees in 27 families by selection according to less than or equal to the 0.0858 lower-assess-value of the best tree’s standard,and three families with the largest number of selected plus trees come from E.urophlla×E.grandis hybrids.The results showed that Eucalyptus urophylla×E.grandis hybrids adapted to the site of Northern Guangxi,and could be selected preferentially in this area.