山杨材性群体变异趋势及个体遗传差异的研究

StudyonPopulationalVariationTendencyandGeneticVariation of WoodQuality of lnter- tree of Populus davidiana

在山杨主要分布区随机抽取６个天然群体，每群体随机抽样１５株采集木芯，分析结果表明：群体间及个体间的木材密度和纤维长度差异都极显著。群体平均密度０．４３２ｌｇ／ｃｍ３，极差０．０６６２ｇ／ｃｍ３；平均纤维长度１．０７７５ｍｍ，极差０．２６５０ｍｍ。东北、华北群体的密度呈梯度变异，纤维长度的梯度变异不明显。木材密度群体重复率０．５４１，个体重复率０．４７１；纤维长度重复率分别是０．４７１与０．４１２。不同群体、不同年轮组的密度与纤维长度的个体重复率有所不同。密度、纤维长度等与生长性状呈微弱遗传相关，可以进行材性与生长的同步遗传改良。

natural populations were selected in the main distribution regions of Popu-lus davidiana and 15 trees were sampled randomly from each population. One increment corewas removed from each sampled tree at breast height for testing wood quality characteristics. The result shows that variations of wood specific gravity and fiber length of inter-tree amongpopulations are both significant at 0.01 level.Mean and extreme deviation of wood specificgravity and fiber length are 0.432 1g/cm3,0.066 2g/cm3,1.077 5 mm,0.265 l mm re- spectively.A gradient variation pattern of wood density has been found among the popula-tions, but that of fiber length not.Repeatability rate of wood density and fiber length of thepopuiation and individual tree are,and of inter- population among annual ring group are differentslightly.Genetic correlation of wood ×growth is lower, which interprets that genetic im-provement of both wood and growth can be carried out synchronizedly.