中文摘要：

为了探究旱涝急转对水稻产量的影响,以“Ⅱ优898”为试材,采用正交试验研究了水稻分蘖期、拔节孕穗期和抽穗扬花期遭遇旱涝急转后的产量及性状规律和跨分蘖-拔节期旱涝急转与单一水分胁迫对作物产量影响的比较。结果表明：（1）单穴穗数主要受分蘖期旱涝急转影响,平均减少1.4穗;每穗粒数受到拔节期旱涝急转影响最大,平均降幅达34.2%;千粒重和成熟粒率主要受控于拔节孕穗和抽穗期的旱涝急转;3个生育期遭遇胁迫产量降幅均达到30%,减产顺序为拔节孕穗期〉分蘖期〉抽穗扬花期。（2）不同生育期遭遇旱涝急转时,产量及其性状主要受控因素和胁迫类型呈现更替变化规律。（3）旱涝急转条件下水稻产量及性状多高于某单一水分胁迫,验证了旱、涝补偿效应的存在。

英文摘要：

In order to explore the influence of abrupt drought-flood on the rice yield, we use Ⅱ You 898 as the material, both the effect of ab- rupt drought-flood during the tillering stage, jointing-booting stage and flowering stage on the rice yield and its traits and comparison of influ- ence on the yield between abrupt drought-flood and single water stress（ drought and flood） across tillering-booting stage were studied through orthogonal experiment. The results indicate： （1） The numbers of panicle per pot is mainly influenced by abrupt drought-flood in the tillering stage, decreasing by 1.4 on average while jointing-booting stage＇s has the greatest impact on the grains per panicle, reducing up to 34.2% ; the 1 000-grain weight and full grain ratio is mainly affected by the abrupt drought-flood in jointing-booting and flowering stage; the specific stress in the three stages all has reduced the yield by more than 30%, and the descending order is： jointing-booting stage 〉 tillering stage 〉 flowering stage. （2） The main factors and stress type which affect yield and its traits remarkably are changing or alternating in the abrupt drought-flood in different stages. （3） Rice yield and its traits are more than the certain single water stress in many cases across tillering-booting stage, which implied the existence of the compensatory effect.