摘要
用电导法、气孔计和扫描电镜等手段研究了温度等微气候要素引起小麦旗叶生理状态的反应和超微结构的变化。认为,在农田微气候调节时,小麦旗叶的光合作用条件,以辐照度高于326.7 w·m^(-2),空气温度27℃以下,二氧化碳浓度尽量提高(至少应维持大气常量)较为理想。室内实验表明,旗叶对温度的反应,以25℃为最适,27℃为逆境界线,超过30℃叶片结构损伤,进入衰老阶段。恶劣的田间微气候对叶片的光合作用不利。高温和低二氧化碳浓度使净光合速率大幅度降低。
The response of physiological state and ultrastructure of wheat flag leaf to the micro-clima- tological factors(especially to temperature)were studied with CO_2 gas analyzer,conductometer,steady state porometer and electronic microscope.The optimal environmental factors to photosynthesis for the wheat flag leaf were:irradiance higher than 326.7 W·m-2;ambient temperature lower than 27℃;and ambi- ent CO_2 concentration as high as possible.The optimal temperature of leaf was 25℃.27℃ was the base line of stress,because above 30℃ the structure of leaf would be damaged.High temperature induced the photosynthetic rate to decrease and made flag leaf decline.The low CO_2 concentration caused the net pho- tosynthetic rate decrease sharply.
