水分胁迫对春玉米光合特性及水分利用效率的影响

Effect of Water Stress on Photosynthetic Characteristics and Water Use Efficiency of Spring Maize

为探明玉米生育中期水分胁迫对光合特性及水分利用效率的影响。2014~2015年在辽宁省农业科学院可移动防雨棚内,以春玉米为试材,采用盆栽方法,设置了正常供水(土壤含水量为田间持水量65%~75%)、轻度水分胁迫(55%~65%)和重度水分胁迫(45%~55%)3个处理,开展了水分胁迫对春玉米叶片叶绿素含量、光合特性、产量、耗水量和水分利用效率影响的研究。结果表明,玉米生育中期水分胁迫不同程度降低了叶片叶绿素含量、净光合速率、蒸腾速率(Tr)、气孔导度,增加了胞间CO_(2)浓度,且下降或增加幅度随着胁迫程度的增加而增大;轻度水分胁迫和重度水分胁迫玉米蒸散量降低了28.9%和54.6%,水分利用效率提高了17.5%和4.1%;轻度水分胁迫对玉米产量影响很小,而重度水分胁迫玉米产量降低了55.6%,严重影响了玉米产量。本研究为该区域玉米提高水分利用效率提供数据支撑。

In order to effect of photosynthetic characteristics and water use efficiency under water stress in the middle of the crop-growing season. Pot experiments were conducted in 2014 and 2015 with a mobile rain shelter of Liaoning Academy of Agricultural Sciences. In experiments under different conditions of soil moisture that normal supply(soil moisture was 65%~75%field water holding capacity), mild water stress(55%~65%), and severe water stress(45%~55%). Photosynthetic pigment, photosynthesis, yield, evapotranspiration, water use efficiency of maize were researched. The results tested that chlorophyll content, net photosynthetic rate, transpiration rate and stomatal conductance were decreased, intercellular CO_(2) concentration was increased under water stress. As water stress level increased they fell or rose more faster;Evapotranspiration of maize was decreased by 28.9% and 54.6%, and water use efficiency was increased by 17.5% and 4.1% under mild water stress and severe water stress.Yield was no significant reduction under mild water stress and that was decreased by 55.6% under severe water stress, so the yield of maize was serious reduction under severe water stress.The results provided theoretical and technical support for improving water use efficiency of maize.