日本落叶松无性系木材组织比量的遗传变异

对10个10年生的日本落叶松无性系木材组织比量进行了测定,结果表明,无性系间木射线比量、树脂道比量和管胞比量差异极显著。日本落叶松组织比量的径向变异规律为:管胞比量由髓心向外,前期变化曲线呈“梯形”,后期变化曲线呈“V”型;木射线比量由髓心向外,开始迅速下降,到第2年轮后缓慢波动下降或上升;树脂道比量由髓心向外,开始缓慢下降,然后迅速上升达最大值后又迅速下降。木射线比量与树木年轮间的变异模式(径向变异)以双曲线和乘幂式方程拟合效果较好,R2均在0.7以上;树脂道比量与树木年轮间的变异模式(径向变异)以指数式方程拟合效果较好,R2为0.609;管胞比量与树木年轮间的变异模式(径向变异)以三次多项式方程拟合效果较好,R2为0.845。日本落叶松的木射线比量、树脂道比量、管胞比量与树高、形率、冠幅、皮厚、主枝粗、枝干比、主枝夹角的相关关系不显著;木射线比量与主枝长显著负相关;木射线比量、树脂道比量与管胞比量之间的相关显著。木射线比量、树脂道比量和管胞比量都受到中等水平的遗传控制,无性系重复力分别是:0.571、0.453和0.607。按照20%的选择率,日本落叶松木射线比量、树脂道比量的遗传增益为16.70%和207.72%。

A Study on Genetic Variation of Wood Tissue Proportion of Japanese Larch Clones

In order to investigate the difference of wood tissue proportion of Japanese larch clone and to provide more theoretical instructions for improving wood properties genetic of Japanese larch,genetic variations of wood tissue proportion of 10 Japanese larch clones at 10 years were investigated.The result revealed that tissue proportion had a significant difference among clones.The proportion of resin showed a highly significant difference among different rings.The prophase variation curve of proportion of tracheid appeared as"Trapezoid"and the latter variation curve appeared as "V"from pith to outward.The proportion of wood ray declined rapidly in the beginning while declined fluctuatly or rose until the second age ring from pith to outward.The proportion of resin canals declined slowly in the beginning,then it rose rapidly to maximum,but declined rapidly again afterwards.The wood ray proportion was well fitted by hyperbola equation and power equation(R~2>0.7).The proportion of resin canals was well fitted by exponential equation(R~2=0.609).The proportion of tracheid was well fitted by cubic polynomial equation(R~2=0.845).The relationship between wood tissue proportion and growth and form was not significant.The relationship between the proportion of wood ray,the proportion of resin and the proportion of tracheid was significant.The broad sense repeatability estimates of clones were 0.571,0.453 and 0.607,indicating the proportion of wood ray,the proportion of resin and the proportion of tracheid were under middle and strong genetic control.The average genetic gains were 16.70% and 207.72% for the proportion of wood ray and the proportion of resin if 20% of the best clones was selected.