干旱胁迫对花期大豆叶片光合特性的影响

Effect of Drought Stress on Photosynthetic Characteristics of Soybean Leaves During Flowering Period

为大豆抗旱栽培及抗旱生理机制研究提供依据,采用盆栽方法,分析轻度干旱（田间饱和含水量的40%-60%）和重度干旱（田间饱和含水量的0%-30%）条件下东北毛豆花期叶片光合特性及水势的变化。结果表明：干旱条件下大豆叶片中水势、净光合速率（Pn）、蒸腾速率（Tr）、气孔导度（Gs）、非光化学淬灭系数（NPQ）、PSII的最大量子效率（fv/fm）和PSⅡ的光能转换效率（ETR）均较对照（正常含水量）降低,细胞间隙CO2浓度（Ci）和固定荧光（Fo）较对照升高。重度干旱、轻度干旱与对照相比,叶片水势分别降低41.5%和18.8%,叶片净光合速率分别降低83.5%和38.0%。重度干旱处理的Fv/Fm值显著高于对照和轻度干旱处理。各处理间的光化学猝灭系数（qP）和非光化学淬灭系数（NPQ）差异极显著。

The leaf photosynthetic characteristics and water potential of Northeast Green Soybean were analyzed under mild drought stress（40%-60% of filed saturation moisture content）and serious drought stress（0%-30% of field saturation moisture content）by apot test to provide the scientific basis for drought resistant cultivation and physiological mechanism of soybean.Results：The water potential,Pn,Tr,Gs,NPQ,fv/fm and ETR of soybean leaves under drought stress are lower than CK but Ciand Foare higher than CK.The water potential and Pn of leaves under serious and mild drought stress decreases by41.5% and 83.5%,and 18.8%and 38.0%compared with CK respectively.Fv/Fmof leaves under serious drought stress is significantly higher than under mild drought stress and CK.There is very significant difference in photochemical quenching coefficient（qP）and non-photochemical quenching coefficient（NPQ）among different treatments.