【摘要】 小麦受渍后叶片的光合和蒸腾速率迅速下降，而后则显微弱的回升趋势。渍害不仅削弱小麦光合产物的积累，并且改变光合产物在地上部分和根系中的分配比例；植株根／冠比下降，而黄叶的发展与根／冠比的变化呈显著负相关；渍害改变小麦的发育进程，尤其是后期渍害明显促使小麦早衰。认为清水使叶片光合速率降低、光合有效面积损失和衰老加速，从而危害小麦的生长。更多还原

【Abstract】 Pot experiments with the treatments of different soil moisture and different flooding duration during three crop development stages were carried out in glasshouse.The leaf net photosynthetic rate (Pn ),stomatal conductance(Gs),cellular CO2 concentration(Ci),and transpiration rate(Tr),root vitality,carbohydrate accumulating rate and its distribution to shoot and root,and the final straw and grain yields were measured. Yelow leaf development and crop development under waterlogging condition were observed.Soil waterlogging lowered wheat leaf photosynthetic rate and transpiration rate.The critical soil moisture of waterlogging for winter wheat is about 90%￣100% field capcity.The response of leaf photosynthesis and transpiration was observed during continuing flooding(Fig.2).Lower stomatul conductance decreased the rates of photosynthesis and traspiration(Fig.3),and the decrease of the raids of photosynthesis was closely correlated with that of transpiration under waterlogging conditions(Fig.4).Waterlogging in the soil not only reduced plant dry matter accumulation but also lowered the ratio of Carbohydrate distribution to root(Table.1),and decreased root vitality.Many of the older leaves died during continuing flooding,and the amount of yellow leaves was closely related to the decrease of root/shoot ratio(Fig.6).When soil waterlogging occurred at the middle or late development singes,plant senesced earlier and grain yield was reduced seriously(Table.2).According to these results,the injury of soil waterlogging to wheat growth can be described from three aspects:the decrease of photosynthesis by means of partial close of stomatal,loss of green leaves and plant senescence.更多还原