日本落叶松无性系木材性质的遗传变异

对10个10年生日本落叶松无性系的木材基本密度、管胞参数进行了测定.结果表明:木材基本密度,早、晚材管胞宽度和早材长宽比无性系间差异显著;木材基本密度,早、晚材管胞长度,早晚材管胞宽度和早晚材长宽比径向变异模式相似,即从髓心向外以曲线形式不断增加,有时亦有起伏;早材从髓心向外以近似直线的形式缓慢增加,晚材从髓心向外以曲线形式增加,初期增加幅度较大,到一定年龄后趋于水平变化并略有波动;材质性状与树木年轮间的关系以对数方程、幂函数方程、指数方程拟合效果较好;除了晚材壁腔比和早材壁厚外,其它木材性质的重复力均在0.5以上,受中度或中度以上的遗传制约,按照20%的选择率,长宽比和晚材管胞长能获得较高的遗传增益.

Genetic Var ia tion ofWood Properties of Japanese Larch Clones

The genetic variations of basic density and tracheid features of 10 Japanese larch clones at 10 yearswereinvestigated. The result revealed that the basic density, tracheid width of earlywood and latewood and tracheidlength2width ratio of earlywood had significant differences among clones. The basic density, tracheid length of earlywood and latewood, tracheid width of earlywood had latewood and tracheid length-width ratio of earlywood and latewood followed the same pattern. The radial variation curveswere increased from p ith to bark , which showed wavessometimes. The tracheid wall thickness of earlywood and latewood and tracheid dull wall thickness-diameter ratiofollowed the same pattern. The latewood was constantly bigger than the earlywood. The radial variation curves of earlywood were slowly increased close to line from p ith to bark. The latewood was increased by curve from p ith to bark.The variation range was large at the initial stages and then became lever variety and slimly waves in a certain age.The variation pattern of wood p ropertity was well fitted by logarithm, power and exponential equations. The repeatabilities of wood p roperty were over 0. 5 excep t tracheid dull wall thickness-diameter ratio of latewood and tracheid wall thickness of earlywood, indicating thatwood p roperty traitswere moderately of strongly genetic control. The genetic gains of tracheid length-width ratio of latewood and tracheid length were higher if 20% of the best cloneswasselected.