生育后期干旱对冬小麦产量和生理特性的影响

盆栽试验的结果表明:后期干旱明显降低冬小麦叶片光合速率和蒸腾速率,并导致保护酶活性下降,MDA累积,叶片衰老加速,硝酸还原酶活性下降,干物质生产受到显著影响。但中度干旱会提高籽粒中酸性转化酶、蔗糖合成酶、碱性转化酶的活性,有利于同化物向籽粒库转运分配;而严重干旱会降低籽粒的代谢活性,不利于同化物向籽粒库转运分配。后期中度干旱对穗粒数、千粒重无影响,对籽粒产量的影响较小,提高了收获指数和水分利用效率。严重干旱显著降低了株高、有效穗数、穗粒数和千粒重,显著降低了产量;同时收获指数和水分利用效率也降低。

The Effects of Drought on the Yield and Physiological Characteristics of Winter Wheat During Later Growth Stage

Using pot experiments,the effects of drought treatment on the wheat yield and the physiological characteristics of winter wheat after heading were studied.The results showed that,the drought treatment apparently had lowered the photosynthesis rate and transpiration rate,resulting in the decrease of SOD,POD,CAT activities,the accumulation of MDA,and enhancing the leaf senescence process,while the NR activity lowered and dry matter production was significantly affected as well.But the moderate drought treatment could promote the activities of acid invertase,sucrose synthetase,and alkaline invertase,and these resulted in the transportation and partition of more photoassimilates into the kernel sink.Severe drought could lower the metabolic activities in the kernels,and it was no good to the transportation and partition of photoassimilates into the kernel sink.The moderate drought treatment at the later growth stage had no effects on the grain number per spike,the weight of 1000 kernels,and had less effect on the grain yield,thus the harvest index and WUE increased.The severe drought treatment significantly lowered the plant height,the effective spike numbers, the grain number per spike and the weight of 1000 kernels,resulting in a siginificant decrease of the yield while the the harvest index and WUE decreased as well.