人工林马尾松木材性质的变异

本文研究了广西人工林马尾松木材性质的变异及幼龄材与成熟材的差异。结果表明 ,幼龄材与成熟材的分界年龄在 14　 16a ,解剖性质在径向上的变异规律为 :射线比量、树脂道比量、胞壁率、胞腔直径、胞壁厚、管胞长度、管胞宽度和晚材壁腔比是自髓心向外呈递增趋势 ,管胞比量和晚材率为递减趋势 ,早材壁腔比和早材腔径比则近似于一条直线。方差分析结果表明 :树脂道比量、胞壁率、胞壁厚、管胞长度和管胞宽度 ,幼龄材与成熟材差异达显著或极显著水平。 5项木材物理力学性质均为成熟材高于幼龄材 ,且均达差异显著水平。木材性质间的相关分析表明 :木材基本密度与管胞长度、管胞宽度、射线比量、树脂道比量、胞壁率呈显著的正相关关系 ,木材气干密度与抗弯强度、抗弯弹性模量、顺纹抗压强度也呈显著的正相关关系

Variations in Wood Properties of Masson Pine (Pinus massoniana L.) Plantation

Under low temperature stress, the contents of the soluble sugar, the soluble protein and the free proline changed significantly. And there are significant correlation between them and the treatment temperature. The specific activity of SOD decreased at first and then increased in the whole. The content of MDA firstly increased, then decreased, and finally increased again. The cold resistance of seedlings of A. mangium was increased by pretreatment with abscisic acid. The result showed that the pretreatment of either 10^-4 mol·L^-1 ABA foR²4 hours or 10^-5 mol·L^-1 ABA for 36 hours was the optimum treatments to improve plant cold resistance.