杜仲对不同光强度的适应性研究

研究了不同光强度下一年生杜仲幼苗的光合生理特性。自然光照、一层遮阴、两层遮阴和三层遮阴杜仲幼苗光饱和点分别为：２５ｋｌｘ，２０ｋｌｘ，１７ｋｌｘ和５ｋｌｘ；光补偿点分别为：４．５ｋｌｘ，４．３ｋｌｘ，２．５ｋｌｘ和１．８ｋｌｘ。随生境中光强度的减弱，叶绿素含量增加，；汁绿素ｂ比例增高。生长在弱光环境中的杜仲幼苗株高受抑，叶面积减小，ＣＯ＿２补偿点降低，固定同化ＣＯ＿２能力减弱，净光合速率较低，导致生物产量和桃叶珊瑚甙地含量降低，表明杜仲是喜阳生植物。

STUDIES ON THE ADAPTATION OF EUCOMMIA ULMOIDES TO LICHT INTENSITY

The photosynthetic physiological characteristies of annual Eucommia ulmoides ,seedlings growing invarious light intensities were determined. The light saturation points and compensation points of Eucom-mia ulmoides seedlings went down, while the contents of chlorophyll and the proportions of chlorphyll in-creased along with the weakening of light intensity of the growing environment. It shows rather strongadaptation of the species to light intensity. The plant height of Eucommia ulmoides seedlings in weak lightintensity is supressed , Its CO_2 compensation point drops, leaf area reduces , the biomass and the contentof aucubin cut down , and the assimilation ability weakens. It shows that Eucommia ulmoides is pho-tophilic plant.