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2年生银杏实生苗遮阴处理4个月后,对其部分形态和生理指标进行了测定.结果表明:(1)就单株叶面积而言,一层遮阴>全光照>二层遮阴>三层遮阴;(2)叶片相对含水率(RWC)、叶绿素含量随着遮阴强度加大而显著提高;(3)就叶片羧化效率(CE)和二氧化碳补偿点而言,一层遮阴与全光照相差不大,二层遮阴和三层遮阴条件下CE值显著降低,而二氧化碳补偿点(Γ)显著升高;(4)就叶片表观量子产量(AQY)而言,二层遮阴>一层遮阴>全光照>三层遮阴;(5)比叶重、净光合速率(Pn)、光饱和点(LSP)和单株叶干重,都随着遮阴强度的加大而显著降低.“,”Based on the four-month shading test of two-year seedlings of ginkgo, some morphological, photosynthetic and physiological indexes were determined. The results showed: (1) there were significant differences in leaf area per seedling among different shading treatments, with a decreasing tendency from one-layer-net shading, to full sun light, to two-layer-net shading and to three-layer-net shading, (2) with the increase of shading intensity, the relative water content and chlorohyll content in leaves went up markedly, (3) as for carboxylation efficiency and CO2 compensation point, there were no remarkable differences between the treatments of one-layer-net shading and full sun light. However, the carboxylation efficiency decreased and CO2 compensation point increased remarkably in the treatments of two-layer-net shading and three-layer-net shading as compared with that in full illumination, (4) in terms of apparent quantum yields of photosynthesis, there were notable differences among different treatments, with a decreasing tendency from two-layer-net shading, to one-layer-net shading, to full sun light and to three-layer-net shading, and (5) with the increase of shading intensity, such indexes as fresh weight per leaf area, net photosynthetic rate, light saturation point and the dried leaves weight per seedling went down apparently.