Abstract: he physiological and growth characteristics, yield formation and dry matter production of 20 mid-season hybrid rice combinations administrated recently were investigated under submergence stress at tillering stage and heading stage. The results showed that: （1）The growth period of mid-season hybrid rice combinations were significantly affected by submergence stress. Under submergence stress at tillering stage, the heading stage of main crop rice and ratoon rice were delayed by 3.25 d and 3.95 d, the maturity stage were delayed by 1.85 d and 2.75 d respectively; however, the maturity stage were decreased by 1.60 d under submergence stress at heading stage. （2）The yields were significantly affected by submergence stress. Compared to the contrast, the yields of hybrid rice combinations with submergence stress at tillering stage decreased by 59.0%, because of the decrease of leaf dry matter, effective panicles and grain number per panicle; the yields of hybrid rice combinations with submergence stress at heading stage decreased by 57.6%, because of the decrease of grain number per panicle and seed setting rate. （3）Strengthen field management to retain the first season rice was better than cutting seedling for growing ratoon rice after 48 h submergence stress at tillering stage, however, planting ratoon rice was a good chance after 48 h submergence stress at heading stage. （4）The submergence tolerance in tillering stage and heading stage is not relevant, the flooding resistance ability should be tested indifferent growth stage in rice production.

Key words: submergence stress, mid-season hybrid rice combination, growth characteristics, yield components

摘要： 以近年审定的20个杂交中稻品种为材料，研究了分蘖期和抽穗期淹涝胁迫对杂交中稻的某些生理指标、生长发育、产量及干物质生产的影响。结果表明：（1）淹没胁迫对杂交中稻的生育期有显著影响。分蘖期受淹没胁迫，头季稻和再生稻的抽穗期分别平均延长了3.25 d和3.95 d，成熟期分别平均延长了1.85 d和2.75 d；而抽穗期受淹没胁迫，成熟期会提前，平均提前1.60 d，且品种间差异较大。（2）淹没胁迫对杂交中稻的产量有显著影响。与对照相比，分蘖期受淹没胁迫，分蘖期叶干重、有效穗数、每穗粒数降低，使其平均减产59.0%；齐穗期受淹没胁迫，每穗粒数和结实率显著降低，使其平均减产57.6%。（3）分蘖期受淹没48 h后，不宜割苗蓄留再生稻，应以加强田间管理保留头季稻为主，耐淹性较强的品种有川谷优6684、冈优169和乐优198；抽穗期受淹没48 h后，则以割苗蓄留再生稻较佳，其中冈优169、内5优317、蓉优22和川谷优6684的产量较高。（4）分蘖期和抽穗期耐淹组合间没有相关性，生产上应分别在各时期筛选相应耐淹能力较强的品种。

关键词: 淹涝胁迫, 杂交中稻, 生长特性, 产量构成