水分胁迫对冬小麦叶片CO_2/H_2O交换参数的影响

水资源严重匮乏已成为华北平原农业可持续发展的主要障碍因素 1] ,提高有限水资源的利用效率显得十分重要。以前的研究主要注重农田水平作物与水分的关系 2 ,4 ] ,利用作物生物学进行节水研究不够 3,4 ] 。Roa等人认为作物适度的水分亏缺可获得高产 15] ;Jensen等人认为适度水分胁迫甚至能使作物水分利用效率显著提高 5,6] ,依此发展了调亏灌溉思想 ,对有限水量在作物生育期内时空最优分配制度进行研究 ,目前已为世界各国广泛关注 6] 。作物 CO2 /H2 O交换参数包括光合速率、蒸腾速率、水分利用效率等 ,这些是确定作物水分高效利用…

Effect of Soil Water Stress on CO_2/H_2O Exchange Parameters in Wheat Leaves.

Changes of CO 2/H 2O exchange parameters were continually measured in winter wheat under different water stress stages.The results showed that photosynthesis rate and transpiration rate of winter wheat in water stress conditions were obviously lower than that in non stress conditions.After water stress,both of them slowly increased and even overtook that on sufficient irrigation treatment. Responses of winter wheat to water stress in different growth stages were different.To some extent, water stress can improve crop water use efficiency,speed up the process of milking.Under water stress condition,stomatal conductance limited diurnal changes of photosynthesis and transpiration in the morning but not in the afternoon.Transpiration is more sensitive to water stress than photosynthesis.