广西引种伞房属三种桉树的生长和抗病性早期选择

Early Selection on Growth and Disease Resistance in Three Corymbia Species in Guangxi

[目的]了解伞房属斑皮桉、大叶斑皮桉和柠檬桉2个亚种(柠檬桉和斑皮柠檬桉)引种广西的生长情况,初步选育抗病的树种、种源、家系,为桉树锯材树种定向培育提供科学依据。[方法]以广西国有三门江林场伞房属桉树种源/家系试验林为研究材料,调查林龄3个月试验林的树高和病害情况,采用抗病指数分析试验林病害情况,方差及变异分析性状差异性与遗传变异情况,独立淘汰法初步选择抗病树种、种源、家系。[结果]树种间树高、保存率、抗病指数差异极显著(P<0.001);斑皮桉和大叶斑皮桉种源间树高、保存率、抗病指数差异不显著,但2树种3性状在家系间差异极显著(P<0.01),斑皮桉抗病指数家系间差异不显著除外;斑皮柠檬桉种源间和家系间树高、抗病指数差异极显著(P<0.001),保存率差异不显著;柠檬桉种源间和家系间仅抗病指数差异极显著(P<0.01)。各性状遗传力和重复力变化范围为0.05~0.43,受弱至中等强度遗传控制。柠檬桉比其他3个树种生长快,最抗病;共选出7个抗病种源和47个抗病家系,其树高、保存率、抗病指数平均值比总体平均值高57.1%、1.8%、67.4%和57.1%、0.9%、69.8%,种源和家系的树高、抗病指数遗传增益分别为12.0%、21.9%和17.1%、21.6%。[结论]选择出的抗病树种柠檬桉、抗病种源和家系为下一步改良提供种质材料。

[Objective]To understand the growth of three Eucalyptus species of the genus Corymbia introduced in Guangxi,and preliminarily select species,provenances and families with disease resistance for providing scientific basis for the orient cultivation of sawn wood.[Method]Based on the 3 month-old provenance/family trail of Corymbia in Guangxi State Sanmenjiang Forest Farm,tree height and disease status were investigated.The disease resistance index was used to analyze the disease status.,Differences between species,provenances,and families were evaluated by analysis of variance.Genetic variation parameters of traits were estimated,and the excellent species,provenances,and families for disease resistance were selected by independent elimination method.[Results]The results showed that:tree height,survival rate and resistance disease index had significant difference among four species(P<0.001);there were no significant difference in height,survival rate and resistance disease index between provenances of Corymbia maculate and Corymbia henryi.The three traits were significant different among the families of these two provenances(P<0.01),except that the disease resistance index of Corymbia maculate was not significantly different among families;there were extremely significant differences in tree height and disease resistance among the provenances and families of Corymbia citriodora ssp.variegate(P<0.001),but the differences in survival rate were not significant;the difference of resistance disease index among provenances and families of Corymbia citriodora were significant(P<0.001),but difference in height and survival rate were not significant.The heritability and repeatability ranged from 0.05 to 0.43,which was controlled by weak to moderate genetic intensity.Corymbia citriodora was the superior species with the best growth and disease resistance.A total of 7 provenances and 47 families were selected.Their mean values of height,survival rate and resistance disease index were 57.1%、1.8%、67.4%and 57.1%、0.9%、69.8%higher than the population mean values,respectively.The genetic gains of height and resistance disease index of provenance and family were 12.0%,21.9%and 17.1%,21.6%,respectively.[Conclusion]The disease-resistant species,provenances and families were selected,which provides basis of germplasm materials for further breeding.