花后干旱对春小麦光合特性及产量的影响

Effects of drought after flowering on photosynthetic characteristics and yield of spring Wheat

为研究花后干旱条件下春小麦光合特性及产量的变化，测定了不同水分胁迫条件下小麦叶片各项光合指标的变化。结果表明：旗叶的蒸腾速率、气孔导度、胞间CO2浓度和水分利用效率随着干旱程度的加剧变化显著，光合速率下降37．67％～86．45％；重度和中度胁迫下Pn的下降主要是非气孔因素造成的，而轻度胁迫下是气孔关闭引起的，最终导致植株早衰，影响小麦籽粒灌浆，使产量降低10．70％～21．20％。

In order to study the changes of characteristics and yield of spring wheat photosynthetic under drought after flowering, the changes of several photosynthetic index of spring wheat leaves under different water stress were measured. The results showed that the transpiration rate, stomata] conductance, intercellular CO2 concentration and water use efficiency of flag leaf changed significantly as water stress increasing, so that the photosynthetic rate decreased by 37.67%-86.45%. The decline of Pn under serious and moderate water stress was mainly due to non-stomata] factors and under light water stress it was because of the decline of stomatal conductance, which caused the wheat premature senescence and influenced the grain filling, so that the yield decreased by10.70%-21.20%