水分胁迫对不同类型春小麦水分利用效率和光合日变化的影响

通过不同生育期3个水分胁迫-复水处理,即:生育期土壤相对含水量(SRWC)维持在饱和持水量的60%~70%(T1),孕穗期SRWC维持35%~45%,之后恢复充足的供水(T2),抽穗期SRWC维持在35%~45%,之后恢复充足供水(T3),研究了旱地类型(DE)、中间类型(IE)和水地类型(WE)春小麦品种水分利用效率和光合日变化.结果表明:水分胁迫对水分利用效率的影响明显小于对籽粒产量的影响,且T2的抑制效应大于T3.无论是T1还是T3,3个品种类型光合日变化均大致呈双曲线,但品种间存在时段性差异.T3处理,DEI、E在15∶00~16∶00表现出光合超补偿作用.在3个处理中,籽粒产量和水分利用效率均呈极显著正相关(0.860~0.965).

Effects of water stress on water use efficiency and photosynthetic diurnal changes of different spring wheat

This study investigated the water use efficiency and photosynthetic diurnal changes of three spring wheat traits which were drought-resistant ecotype(DE),wet ecotype(WE) and intermediate ecotype(IE),through three water stress on water supplies(T1 was a well water supply,maintaining soil relative water content(SRWC) at 60 %～70 % of saturated water capacity in whole growing period;T2:SRWC of 35 %～45 % at booting stage,then recovered to well water supply.T3:SRWC of 35 %～45 % at heading,then to well water condition)in different growth stages.The results showed that the impact of water stress to water use efficiency was obviously less than that of grain yield per pot of wheat,moreover,the inhibition effect of T2 on above traits was heavier than that of T3.Whether in T1 or T3,diurnal variations of net photosynthetic rate of three ecotypes generally changed as bimodal curve,and there were differences among photosynthetic rate of wheat cultivars for measuring times.Under T3,there emerged stronger exceeding compensation effects from 15∶00 to 16∶00.In all treatments,grain yield were highly significant positive correlated with significant positive correlation(0.860～0.965).