淮北平原旱涝急转条件下水稻减产规律分析

为探究水稻旱涝急转下先期旱胁迫与后期涝胁迫交互作用对产量造成的影响,于2016年在淮委水科院新马桥试验站开展了不同旱涝水平(受旱程度(50%~70%田持),受旱时间(5~15 d),受涝程度(50%~100%株高),受涝时间(5~9 d))的旱涝急转组,单旱组,单涝组,正常组平行对比形式的测桶试验。分析了不同旱涝组合形式下先旱与后涝互作效应的减产规律,进一步探究了旱涝互作对产量构成因素的影响。结果表明:通过旱涝急转组与正常组对比,重旱重涝组合减产30.3%,对产量最为不利,长时间重旱使总粒数削减30%左右,千粒质量与结实率均接近或高于正常组;旱涝急转组与单旱组对比,旱涝急转组(重涝)比单旱组产量削减程度增加30%以上,总粒数损失增加33.9%~35.2%,旱涝急转组(短期轻涝)比单旱组(长期重旱)千粒质量和结实率分别补偿33.6%和37.6%;旱涝急转组与单涝组对比,旱涝急转组(长期轻旱)比单涝组(长期重涝)产量补偿113.0%,旱涝急转组(重旱)比单涝组(重涝或长期轻涝)总粒数削减31.9%~33.7%,旱涝急转组(长期旱)比单涝组千粒质量和结实率分别补偿79.7%和118.4%。研究成果可为探究旱涝急转致灾机理及减灾措施提供参考。

Analysis on yield reduced law of rice in Huaibei plain under drought-flood abrupt alternation

Abstract: Drought and flood are important abiotic stresses negatively affecting plant growth and development. In recent years, the frequent occurrence of drought-flood abrupt alternation (DFAA) has made crops often need to bear double stresses of drought and flood. In order to explore the response of rice yield to the double stresses of DFAA, a field experiment was conducted using a mid-season Indica hybrid rice cultivar of II you 898 which is cultivated widely in Jianghuai Area with 22 treatments of different drought degrees (50%, 60%, 70% field water-holding rate), different drought time (5, 10, 15 d), different submergence depths (1/2, 3/4, whole plant height) and different flooded time (5, 7, 9 d) in 2016. Twenty-two treatments included 6 treatments with drought followed by no flood (DC), 6 treatments with flood followed by no drought (FC), 9 treatments with DFAA and 1 treatment without drought and flood (CK). At drought stage, the barrels are moved to the side of flooded pool, and their weights are measured at 7:00 am and 6:00 pm daily. The barrels are added with water to meet the requirements of drought stress control. In order to avoid the impact of rain, the shelter is used in advance according to the weather forecast. At flood stage, the barrels are moved to different ladders of flooded pool according to the requirements of different submergence depths. The water level of flooded pool is measured with a ruler at 9:00 every morning, and a certain amount of water is irrigated so that the barrels are able to maintain different submergence depths. In case of rainy days, the flooded pool was drained timely to meet the requirements of flood stress control. The barrels of normal treatment have been placed on the top ladder of flood pool, keeping 2-3 cm water level. The compensation effect of the interaction between drought stress and flood stress on rice yield is calculated. The reason of reduction in yield under the interaction between drought and flood is analyzed, and the effect of the interaction on yield components is explored. It''s shown from the results that, compared with the normal group, the yield of DFAA group of combination of heavy drought and heavy flood was reduced by 30.3%, and the total grain number was decreased by 30.6% under long-term heavy drought, while the 1000-grain weight and seed setting rate of each treatment group were close to or higher than the normal group. Besides, compared with the drought group, the yield and total grain number of DFAA group (heavy flood in later stage) were reduced by 30.8%-33.9% and 33.9%-35.2%, and 1000-grain weight and seed setting rate of DFAA group (short-term light flood) could respectively compensate for 33.6% and 37.6% compared with the drought group (long-term heavy drought). At last, compared with the flood group, the yield of DFAA group (long-term light drought) could compensate for 113.0% compared with the flood group (long-term heavy flood), the total grain number of DFAA group (heavy drought) was reduced by 31.9%-33.7% compared with the flood group (heavy flood or long-term light flood), and the 1000-grain weight and seed setting rate of DFAA group (long-term drought) could compensate for 61.4%-79.7% and 54.3%-118.4% respectively compared with the flood group. The research results can provide a reference for exploring the mechanism of DFAA and disaster mitigation measures.