小兴安岭地区白桦纸浆材优良家系选择

Preliminary Selection of Betula platyphylla Superior Family for Pulpwood Production

以59个白桦(Betula platyphylla Suks.)自由授粉家系子代测定林为研究对象,对树高、胸径、纤维长度、纤维宽度、纤维长宽比、苯醇抽提物含量和综纤维素含量7个性状进行了差异显著性分析和多重比较分析,运用选择指数法开展了白桦纸浆材优良家系选择,并对这些入选家系作了遗传增益估算。结果表明:这些性状在家系间差异达到极显著水平,各性状家系遗传力为0.52～0.92;遗传变异系数除树高(20.71%)较大外,其它性状皆小于5%。对7个性状进行了多重比较并绘制了散点图,发现选择的性状标准不同,选择出的优良家系也不尽相同。进一步运用等权重的指数选择方法综合选择出了7个生长和材性兼优的家系。入选家系各性状的遗传增益为0.24%～9.52%,生长性状的遗传增益大于材质性状的遗传增益。

A study was conducted to discuss the significant differences in tree height, diameter at breast height （DBH） , fiber length, fiber width, ratio of fiber length to width, benzene-alcohol extractive content and holocellulose content between 59 filial generations derived from open-pollinated Betula platyphylla families, and multiple comparisons were also made. According to the selection index method, superior families for pulpwood purpose were selected on the southern slope of Xiaoxing＇ an Mountains, and the genetic gains for the selected superior families were evaluated. Extremely significant differences in the traits were found and the heritabilities of the families ranged from 0. 52 to 0. 92. The genetic variation coefficient of tree height was the highest （20.71%）, while those for other traits were less than 5%. Duncan＇ s multiple comparison of the seven traits was made and a plot was drawn. Results showed that the selected family would be different if the criterions for the selective traits were various. Seven fast growing families with good wood qualities were selected by the method of selection index with equal weight. The genetic gains of the selected families were between 0.24% and 9.52% , and the genetic gains of growth traits were higher than those of wood quality traits.