马尾松无性系木材基本密度和纤维形态的变异及选择

Genetic variation of wood basic density and fiber morphology and selection of Pinus massoniana

【目的】研究马尾松Pinus massoniana在产地间和产地内的无性系木材基本密度和纤维形态的遗传变异规律,为马尾松良种选育和改良提供优质的遗传材料。【方法】从浙江省淳安县姥山林场34年生马尾松无性系试验林中,选出5个不同产地的50个无性系为研究对象,测定其木材基本密度、纤维长度、纤维宽度和纤维长宽比。通过方差分析、相关性分析及遗传参数估算揭示其遗传变异规律,并采用独立选择标准法对50个无性系进行选优。【结果】方差分析结果表明:木材基本密度、纤维形态在产地间和产地内的无性系间皆存在显著(P<0.01)或极显著(P<0.001)差异。其中,木材基本密度、纤维长度和纤维长宽比变异主要来源于产地内无性系间,占总变异的19.37%~28.26%;纤维宽度的遗传变异主要来自于产地间变异,占总变异的45.57%。木材基本密度与纤维长度、纤维长宽比存在极显著(P<0.001)的表型和遗传负相关,与纤维宽度相关不显著(P>0.05)。纤维形态指标在幼龄—成熟期呈极显著(P<0.001)的遗传正相关,而木材基本密度在幼龄—成熟期的相关不显著(P>0.05)。共选出12个材性优良的马尾松无性系。【结论】马尾松木材基本密度、纤维长度、纤维长宽比3个性状在改良过程中应注重产地内优树的选择。而纤维宽度通过产地间选择能达到较好的改良效果。鉴于纤维形态在幼龄—成熟期相关性极显著,可作为材性早期选择指标。

[Objective] With an analysis of the genetic variation of wood basic density and fiber morphology of Pinus massoniana among seed sources and clones within seed sources, this paper is aimed to provide high quality genetic material for the breeding and improvement of P. massoniana. [Method] Fifty clones from five seed sources of P. massoniana clones selected from 34-year-old experimental forests of different seed sources in Laoshan Forest Farm, Chun’an County, Zhejiang Province, were investigated to determine the wood basic density, fiber length, fiber width and fiber length-width ratio. Then variance analysis, correlation analysis and genetic parameter estimation were conducted to reveal the genetic variation while superior individuals wereselected from the 50 P. massoniana with the employment of Independent Selection Standard Method. [Result]The results of ANOVA revealed that there were significant or extremely significant differences in the basic density and fiber morphology of the wood among seed sources and clones within seed sources. The variation of clones within seed sources with the variance components ranging from 19.37% to 28.26% was the main source of wood basic density, fiber length and fiber length-width ratio. The variation of seed sources with the variance components(45.57%) was the main source of fiber width. There is a significant phenotypic and genetic negative correlation between basic densities of wood and fiber length and fiber length/width, but the correlation coefficient is not high and the basic densities of wood is not related to fiber width. The fiber morphological indexes showed significant positive genetic correlation in the juvenile age and mature age, while the wood basic density showed no significant correlation in the juvenile age and mature age. A total of 12 clones of P.massoniana with excellent wood properties were selected. [Conclusion] More attention should be paid to the selection of superior trees within seed sources in the attempt to improve the three traits of wood basic density,fiber length and fiber length-width ratio. On the other hand, the fiber width can be better improved through the choice of seed sources. In view of the significant correlation of fiber morphology indexes between juvenile and mature timber, they can be selected as reference indexes in the early stage.