毛棉杜鹃幼苗的光适应性研究

    Light adaptablity of Rhododendron moulmainense seedling

    • 摘要: 毛棉杜鹃是我国观赏价值较高的观花树木,在我国南部天然林中广泛分布,但极少在城市园林中应用。应用盆栽试验方法比较研究了毛棉杜鹃幼苗在全光照半光照50%全光照和低光照25%全光照下生长表现和生理生态特性,结果表明院1毛棉杜鹃幼苗的高生长在全光照条件下较快,但冠幅生长以半光照条件较快,弱光会抑制幼苗的高生长和冠幅生长,导致其比叶面积和根冠比增大2在夏季强光下毛棉杜鹃的幼芽和叶片易受灼伤,苗木的净光合速率最小初始荧光FoPS域最大光化学效率Fv/Fm也明显受抑3毛棉杜鹃幼苗对弱光有一定的适应能力遮荫条件有利于其叶绿素含量的增加并通过最大光学效率Fv/Fm潜在光化学效率Fv/Fo和光补偿点的调节提高其光能利用效率。

       

      Abstract: Rhododendron moulmainense is a native Rhododendron tree with high ornamental value, widely distributes in Southern China, but seldom applies in urban landscape. The effects of different light conditions including full light (100% of full light), partial shade (50% of full light) and deeply shade (25% of full light) on the growth performance and physiological characteristics of pot-cultured seedlings were studied. The results showed: (1) Seedling height growth under full light was fast, but crown growth under partial shade was fast. Deeply shade would inhibit the height and crown growth of the seedlings, which resulted in higher specific leaf area and root shoot ratio. (2) Seedling leaves and buds were vulnerable to scorch in summer. The net photosynthetic rate, Fo and Fv/Fm were inhibited under full light.(3) R. moulmainense could adapt to low light condition because shade could enhance its total chlorophyll content, increase Fv/Fm, Fv/Fo, and decrease LCP.

       

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