中文摘要：

大田种植超级稻品种两优培九（两系杂交籼稻）和淮稻9号（粳稻）。自抽穗至成熟设置轻干-湿交替灌溉（WMD）、重干-湿交替灌溉（WSD）和常规灌溉（CI, 保持水层） 3种灌溉方式, 观察其对超级稻灌浆的影响。结果表明, 与CI相比, WMD处理显著增加2个超级稻品种的产量、结实率和粒重, 而WSD处理则降低结实率和粒重。WMD处理显著提高灌浆期剑叶净光合速率、膜质过氧化酶活性和根系氧化力、根系吸收表面积、根系活跃吸收表面积、比表面积和根系中玉米素＋玉米素核苷（Z＋ZR）及吲哚-3-乙酸（IAA）含量及根冠比, WSD处理的结果则相反。说明结实期轻干-湿交替灌溉可以改善超级稻根系和地上部植株的生理功能, 进而提高结实率和粒重。

英文摘要：

Two super rice cultivars, Liangyoupeijiu and Huaidao 9, were used in the study. Three irrigation regimes, including alternate wetting and moderate soil drying （WMD）, alternate wetting and severe soil drying （WSD）, and conventional irrigation （CI, continuous flooding）, were imposed from heading to maturity. Compared with CI, WMD significantly increased, whereas WSD decreased, seed setting rate and grain weight of super rice. The photosynthetic rate, activities of membrane lipid peroxidation enzymes in the flag leaf, root oxidation activity, root absorption surface area, root active absorption area, root specific surface area, contents of zeatin ＋ zeatin riboside （Z＋ZR） and indole-3-acetic acid （IAA） in roots and the ratio of root to shoot were increased under the WMD regime, but decreased under the WSD regime. The results suggest that the WMD irrigation during grain filling could improve root and shoot physiological functions, and consequently increase the seed-setting rate and grain weight of super rice.