遮阴对石笔木苗木生长和保护酶活性的影响

为探讨石笔木Tutcheria championi苗木对遮阴环境的适应性，以全光照(无遮阴覆盖)为对照，研究遮阴30%、50%和70%对2年生石笔木苗生长和生理特性的影响。结果表明，全光照下石笔木苗木生长较为健壮，其苗高、地径生长优于遮阴处理；全光照下石笔木总生物量、根生物量比以及根冠比显著大于遮阴处理(P<0.05);50%遮阴处理苗木叶片叶绿素含量显著高于全光照和70%遮阴处理(P<0.05)，叶绿素a/b值在各处理间无显著差异。丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性在各处理间无显著差异(P>0.05);70%遮阴处理的苗木叶片过氧化氢酶(CAT)活性最高，显著高于全光照和50%遮阴。由此表明，充足的光照环境有利于石笔木苗木生长。

Effect of Shading on Growth and Protective Enzyme Activities of Tutcheria championi Seedlings

In order to observe the adaptability of Tutcheria championi seedlings to shading environment, using full light (no shading) as control, the influence on the growth and physiological characteristics of two-year T. championi seedlings were investigated under the conditions of 30%, 50% and 70% shading. The results showed that the seedlings under full light was stronger than the other treatments, the seedling height, ground diameter were higher than the seedlings under shading treatments. The total biomass, root mass ratio and root shoot ration of seedlings under full light were significantly higher than seedlings under shading treatments. The chlorophyll content of seedling leaves under 50% shading was significantly higher than that under full light and 70% shading (P<0.05), and there was no significant difference in chlorophyll a/b value among all treatments. There were no significant differences in malondialdehyde (MDA) content and superoxide dismutase (SOD) activity among all treatments (P>0.05). Catalase (CAT) activity was the highest in the 70% shading treatment, which was significantly higher than those of full light and 50% shading treatments (P<0.05). Therefore, sufficient light is good for the growth of T. championi seedlings.