【摘要】 【目的】为了探明槲树(Quercus dentata)苗期生长的适宜光照强度，为其在城市森林建设应用中提供参考。【方法】以槲树幼苗为试验材料，设置全光照(CK)、75%全光照、50%全光照、25%全光照4个光照梯度，处理60 d后，测定生长指标、叶解剖结构、生理指标和光合参数。【结果】75%全光照下槲树幼苗生长状况最佳，有利于生长。随着遮阴程度增加，槲树幼苗的叶片、栅栏组织、海绵组织、主脉、上表皮和下表皮的厚度均减小，栅海比减小，而细胞疏松度增加。过氧化物酶、超氧化物歧化酶、过氧化氢酶的活性随着遮阴程度的增加先降低后升高，可溶性糖、可溶性蛋白、脯氨酸与丙二醛的含量表现出相似的变化规律。遮阴处理消除了槲树幼苗的光合午休现象，并且提高了光能利用效率，减少了暗呼吸消耗，有利于光合产物的积累。【结论】槲树幼苗具有一定的耐阴性，75%全光照是适宜槲树苗期生长的光照强度。更多还原

【Abstract】 [Objective]This studyaimed to determine the optimal light intensity for the seedling growth of Quercus dentata Thunb. and provide reference for its application in urban forest construction.[Methods]Q. dentata seedlings were used as experimental materials. Four different light levels including full light exposure(CK), 75% full light exposure, 50% full light exposure, and 25% full light exposure were set up. After treatment for 60 days, the growth indexes, leaf anatomical structure, physiological indexes, and photosynthetic characteristics were measured. [Results]Under 75% full light exposure Q. dentata seedlings presented the best growth status, which promoted the growth. As the increase of shading levels of, the of thicknesses of leaf, palisade tissue, spongy tissue, main vein, upper epidermis, and lower epidermis of Q. dentata seedlings decreased, as well as the palisade-spongy ratio, but the cell looseness increased. The activities of peroxidase, superoxide dismutase, and catalase initially decreased and then increased with increased shading levels. The contents of soluble sugars, soluble proteins, proline, and malondialdehyde followed a similar trend. Shading treatment eliminated the hotosynthetic lunch break phenomenon of Q. dentata seedlings, enhanced the light energy utilization efficiency, and reduced dark respiration consumption, which contributed to the accumulation of photosynthetic products. [Conclusion] Q. dentata seedlings exhibited a certain degree of shade tolerance, and 75% full light exposure was optimal for the seedling growth of Q. dentata.更多还原