美洲黑杨无性系木材材性与生长性状遗传相关分析

Genetic correlation analysis of wood pr operty and gr owth traits in Populus deltoides clones

【目的】通过对美洲黑杨无性系材性性状与生长性状遗传相关性的研究,了解杨树材性性状与生长性状的相关变异规律,为杨树纸浆材材性改良提供科学依据。【方法】以泗洪县陈圩林场11个美洲黑杨无性系11年生对比试验林为材料,通过遗传相关分析、通径分析及典型相关分析等方法,揭示杨树无性系材性性状与生长性状的相关变异规律。【结果】11个美洲黑杨无性系生长性状树高、胸径和材积之间呈极显著正遗传相关。材性性状纤维长和基本密度与纤维长宽比之间呈极显著正遗传相关,纤维宽与纤维长宽比之间遗传相关性不明显,同一纤维性状在幼龄期(第3龄)、过渡期(第6龄)、成熟期(第9龄)之间均表现出极显著遗传相关性。纤维长和纤维宽与生长性状间呈极显著正遗传相关,基本密度与生长性状间呈显著负遗传相关,纤维长宽比与生长性状间无论在表型还是遗传上其相关性不显著。通径分析表明,胸径与纤维宽对材积的直接作用较大,树高与纤维长对材积的间接作用较大,基本密度对材积的直接或间接作用为负,而纤维长宽比对材积的直接或间接作用影响较小。典型相关分析得出,纤维性状与生长性状间相关主要由纤维宽与材积之间相关引起,与通径分析结果一致。【结论】美洲黑杨纤维形态指标在早材第3龄与晚材第9龄间呈极显著正遗传相关(P<0.01),可作为材性早期选择指标。纤维长和纤维宽与生长性状间存在紧密正遗传相关,纤维长宽比与生长性状之间遗传相关不显著。3个生长性状的遗传相关贡献较大(18.47%、20.20%、20.47%),在所有性状相关变异中起较大作用,纤维长宽比的遗传相关贡献最小(7.38%),性状较为稳定。美洲黑杨材积生长量的主要构成因素为树高、胸径、纤维长和纤维宽。

【Objective】To understand the genetic basis of genetic correlation in wood properties and growth characteristics in Populus deltoides clones,the correlation of growth and wood traits was analyzed to provide a scientific basis for poplar pulp wood property improvement.【Method】Eleven different clones of 11-year-old P.deltoides plants were selected as materials for clonal testing in field experiment,and planted in Chenwei forest farm,Sihong county.The genetic correlation analysis,path analysis and canonical correlation analysis were taken to reveal the rule of genetic correlation of growth and wood property for the 11 poplar clones.【Result】The correlation analysis indicated an extremely significant positive genetic correlation between the three growth traits of 11 P.deltoides clones,including tree height,DBH and volume.The fiber length and basic density were significantly or highly significant and positively correlated with fiber length-width ratio.The genetic correlation between fiber width and fiber lengthwidth ratio was not obvious.Each fiber trait showed high genetic correlation between different age groups.There was a significant positive genetic correlation between fiber length,fiber width and growth traits,a significant negative genetic correlation between basic density and growth traits,and no significant phenotypic or genetic correlation between fiber length-width ratio and growth traits.The path analysis showed that the direct effect of DBH and fiber width on volume was greater,the indirect effect of tree height and fiber length on volume was higher,the direct or indirect effect of basic density on volume was negative,and the direct or indirect effect of fiber length-width ratio was less.The canonical correlation analysis showed that the correlation between fiber traits and growth traits was mainly caused by the correlation between fiber width and volume,which was consistent with the results of path analysis.【Conclusion】The fiber morphological indexes of P.deltoides showed significant positive genetic correlation in the juvenile age and mature age,which can be used as an index for early selection of wood properties.There was a close positive genetic correlation between fiber length,fiber width and growth traits,but there was no significant genetic correlation between fiber length-width ratio and growth traits.The genetic correlation contribution of the three growth traits was larger(18.47%,20.20%,20.47%),which played an important role in the correlation variation of all traits.The genetic correlation contribution of fiber length-width ratio was the lowest(7.38%),and the character was relatively stable.The main factors of volume growth of P.deltoides are tree height,DBH,fiber length and fiber width.