【目的】全球气候变化异常导致旱涝急转事件频发,为保障国家粮食安全,做好农作物的防灾减灾工作,研究了旱涝急转条件下水稻的减产特征。【方法】以淮北平原区水稻为试验对象,在淮委水利科学研究院新马桥农水试验站(117°22′E,33°09′N)开展了为期两年(2017–2018年)的水稻旱涝急转胁迫试验,分析了不同旱涝胁迫程度、不同胁迫持续时间的单一干旱、单一淹涝、旱涝急转胁迫对水稻产量及产量构成的影响,提出先期旱与后期涝的补偿、削减作用量化指标R,揭示了旱涝急转后期淹涝胁迫与前期干旱胁迫对水稻产量影响的交互作用新规律。【结果】拔节期发生旱涝急转产量普遍减少,减产范围12.38%~56.15%。其中,重旱重涝组合对产量最为不利,粒数与粒重减少是旱涝急转胁迫条件下水稻减产主要原因;旱涝急转处理下前期适度干旱可减轻后期淹涝导致的减产,即旱涝急转旱胁迫对涝胁迫具有产量上的补偿效应,主要是提高了每穗粒数、总粒数和结实率;而后期淹涝对前期干旱具有协同作用,表现出产量上的削减效应,主要是每穗粒数、总粒数、千粒质量、结实率的减少。【结论】前期已经发生了轻、中旱胁迫,应尽量避免后期淹涝对水稻的二次损伤;若预测到后期将出现洪涝,并且短时间内田间排水设施无法消除其不利影响,则可提前在水稻拔节中、后期进行旱锻炼以减轻水稻产量损失。

【Objective】Abnormal global climate change leads to the reoccurrence of abrupt drought-flood alternation (ADFA). In order to national food security and disaster prevention and reduction in crops, we analyzed yield response characteristics of rice to ADFA. 【Method】The experiment was conducted at the Xin-maqiao irrigation experimental station at the Anhui and Huaihe River Institute of Hydraulic Research in China (117°22′E, 33°09′N) between 2017 and 2018. Three drought-flood alternation treatments were designed and compared with normal irrigation conditions. Based on the experimental data, the effects of drought, flood, and ADFA on rice yield and yield components were analyzed, the quantitative indicator R for the compensation or reduction of the early drought and later floods was proposed, and the interaction effects between late flooding stress and early drought stress on yield was revealed.【Result】Compared with the normal group, ADFA stress reduced the rice yield. The yield reduction ranged from 12.38% to 56.15%. Among them, the combination of heavy drought and heavy flood was the most unfavorable for yield. The reduction in the grain number and the grain weight was the main reason for yield reduction under ADFA stress. The drought stress of the ADFA groups compensated the yield under flood conditions, mainly because the grain number per panicle, total grain number and seed setting rate increased during the drought period. The flood stress of the ADFA groups reduced the yield under drought conditions, and the decrease in the grain number per panicle, total grain number, thousand-seed weight and seed setting rate during the flooding period was the main reason. 【Conclusion】The results show that in the case of light and moderate drought stress occurring at the early stage, the damage caused by late-stage flood stress on rice should be avoided as possible; if flooding is predicted to occur in the later period and the drainage facilities can not eliminate its adverse effects, drought treatment can be carried out in advance at the medium-late period of the jointing stage to reduce the loss of rice yield.