大花序桉种源/家系生长性状和树干通直度及基本密度的评价与选择

Evaluation and selection for growth traits,stem straightness and basic density of Eucalyptus cloeziana provenances/families

【目的】评价大花序桉种源/家系的生长性状、树干通直度和基本密度,选择生长、干形和材质兼优的实木材优良种源/家系,为其高世代育种及生产造林提供高质量的遗传材料。【方法】分析广西玉林市林业科学研究所林龄为115个月的17个种源和115个家系大花序桉种源/家系试验林的生长性状、遗传参数及遗传相关,以t检验进行单性状选择,采用独立淘汰法综合选择大花序桉优良种源/家系。【结果】大花序桉种源/家系的生长性状、树干通直度和基本密度在种源间差异显著(P<0.05,下同),生长性状和基本密度在种源内家系间差异显著,树干通直度在种源内家系间差异不显著(P>0.05,下同)。遗传变异系数变幅为2.38%(基本密度)~20.48%(单株材积),树高、树干通直度和基本密度受弱遗传控制,胸径和单株材积受弱至中等强度遗传控制。相关性分析结果表明,生长性状间存在极显著遗传正相关(P<0.01,下同);生长性状与树干通直度呈极显著遗传负相关;基本密度与树高呈极显著遗传负相关,与胸径、单株材积呈遗传负相关;树干通直度与基本密度的遗传相关不显著。胸径和树干通直度显著大于总体平均值的分别有7个和3个种源,其中种源20724的综合性状最优。胸径、基本密度和树干通直度显著大于总体平均值的分别有23个、11个和9个家系,共选出17个综合性状最优家系。【结论】根据培育目标大花序桉的生长性状与树干通直度、基本密度与树高进行独立改良;选出的综合性状优良的1个种源(20724)和17个家系可直接应用于生产。

【Objective】The genetic variations of growth,stem straightness and basic density of Eucalyptus cloeziana provenance/family were evaluated,of the excellent families and provenances with good growth,stem form and wood property were selected for solid wood,to provide high-quality genetic material for the high-generation breeding and forestation.【Method】The 115 month-old 17 provenance/115 family trail of E. cloeziana in Yulin Forestry Research Institute as the researched materials,the differences,genetic parameters and genetic correlations were analyzed,single trait selection by t significance test method,excellent provenances and families were chosen by independent eliminated method.【Result】The results showed that,the differences between provenances for growth,stem straightness and basic density were significant(P<0.05,the same below),the differences among families within provenances for growth and basic density were significant,but the stem straightness was not significantly different(P>0.05,the same below). The range of variation of genetic variation coefficient was 2.38%(basic density)-20.48%(individual volume),the height,stem straightness and basic density were weak genetic controlled,and diameter at breast height,individual volume were weak to moderate genetic controlled. Correlation analysis showed extremely positive genetic correlation among the height,diameter at breast height,individual volume(P<0.01,the same below);the genetic correlation between growth traits and stem straightness showed extremely significant negative correlation,the basic density and height showed extremely negative correlation;the basic density with diameter at breast height and individual volume showed negative genetic correlated,the basic density with stem straightness showed no significantly negative genetic correlated. Respectively 7 provenances and 3 provenances whose diameter at breast height and stem straightness were significantly greater than the overall average,the provenance20724 was excellent provenance with good comprehensive traits. Respectively 23,11,9 families whose diameter at breast height,stem straightness significantly and basic density were greater than the overall average,there were 17 families with good comprehensive traits were chosen.【Conclusion】The growth and stem straightness,basic density and height of E.cloeziana should be carry on independent choices. The provenance 20724 and 17 families are selected with excellent comprehensive properties,the selected provenance and families can be used in production.