关键词: 杂交水稻, 淹涝, 受涝时间, 株高, 节间, 产量, 结实率

Abstract: In Hubei plain area, there is a plenty of rainfall in summer, so that rice plants are liable to suffer from waterlogging damage. In order to know the influences of waterlogging on hybrid rice in growth and yield, Fengliangyouxiang 1 (one of the hybrid rice varieties) was used as the test material, and the experiments of waterlogging stresses on it were made individually in the jointing, booting and filling stages, the experimental treatments were designed as different combinations of waterlogged depth and waterlogged time (3, 6 and 9 days). The results showed that, after waterlogging stress, the rice height and the internode length all present elongation. At filling stage and booting stage under waterlogging stress, the plant height growth rate was greater than the jointing stage. The linear relationship between the hybrid rice height increase (YPH), internode height (YIL) and waterlogged days (D), waterlogged depth (H) was significant, correlation coefficient was up to more than 0.9000, and the waterlogged depth had a greater influence on the plant height and internode length than waterlogged days. The reduction of output that caused by waterlogging stress at different stages of rice was different, the order was booting stage＞jointing stage＞filling stage. The linear relationship between the relative yield (Ry) and D, H was significant, correlation coefficient was up to more than 0.9000, and waterlogged days had a greater influence on the yield than waterlogged depth at jointing and filling stage, in contrast, at booting stage. As far as yield component was concerned, waterlogging stress at jointing stage lead to yield loss mainly because seed setting rate decreased, while at booting stage 1000-grain weight and seed setting rate decreased, at filling stage mainly in the following aspects, first, the decline of seed setting rate, then, the decrease of effective ears. At jointing stage, booting stage and filling stage under waterlogging stress, the relative moisture index of the lower panicle was 0.69%-44.01%, 20.87%-71.14% [100% for completely submergence for 9 days (aliased as CS9)] and 3.15%-81.84% respectively, the relative moisture index of the central panicle was 4.49%-32.36%, 14.31%-62.21%（100% for CS9）and 10.02%-66.89% respectively, and the relative moisture index of upper panicle was -0.77%-14.72%, 7.64%-50.10%（100% for CS9）and 2.75%-59.66%.

Key words: Hybrid rice, Waterlogged depth, Waterlogged time, Rice height, Internode, Yield, Seed setting rate