不同生育期干旱胁迫对玉米籽粒灌浆及产量的影响

为研究不同生育期干旱胁迫对玉米籽粒灌浆及产量的影响，分别设置正常水分、拔节期干旱、抽雄期干旱和灌浆初期干旱4个处理，研究玉米干物质积累、灌浆特性、淀粉相关酶活性及产量的变化特征。结果表明:干旱显著降低玉米干物质积累量，抽雄期和灌浆初期干旱显著降低花后干物质积累量和贡献率；干旱显著降低籽粒质量和灌浆速率，抽雄期干旱对后期籽粒质量和灌浆速率影响最大；干旱显著降低结合态淀粉合成酶（GBSS）、可溶性淀粉合成酶（SSS）、蔗糖合成酶（SS）和蔗糖磷酸合成酶（SPS）活性；干旱对产量的影响主要是增加了秃尖长、减少了行粒数，3个时期干旱胁迫产量分别降低15.15%、33.11%和22.00%。因此，拔节期、抽雄期和灌浆初期玉米对水分的需求较为敏感，对产量影响较大，尤其是在玉米抽雄期，要确保水分供应，以保证玉米产量。 

Effect of Drought Stress in Different Growth Stages on Corn Grain Filling and Yield

In order to study effects of drought stress in different growth stages on corn grain filling and yield，four treatments were set up，namely normal water，jointing stage drought，tasseling stage drought，and early filling stage drought，changes of dry matter accumulation，filling characteristics，starch related enzyme activity and yield of maize were studied.Results showed that drought significantly reduced dry matter accumulation of corn，and drought during tasseling stage and early filling stage significantly reduced dry matter accumulation and contribution rate after anthesis.Drought significantly reduced grain weight and filling rate，and drought during tasseling stage had a significant effect on dry matter accumulation.Drought significantly reduced activities of bound starch synthase（GBSS），soluble starch synthase（SSS），sucrose synthase（SS）and sucrose phosphate synthase（SPS）.Drought has an effect on yield，main effects of the corn were increasing length of bald tip and reducing number of rows.Yield of three periods of drought stress decreased by 15.15%，33.11%，and 22.00%，respectively.Therefore，jointing stage，tasseling stage and early stage of grain filling were more sensitive to water demand，has a greater impact on yield，especially in the corn tasseling period.Water supply should be ensured to ensure corn yield.