不同受旱胁迫下大豆蒸发蒸腾与地上部生长物质之间响应关系研究

Study on Response Relationship between Evapotranspiration and Aboveground Growth Matter of Soybean under Different Drought Stress

农业旱灾损失形成过程中存在着大量的不确定性,不同受旱胁迫下作物蒸发蒸腾与生长物质积累之间的定量响应关系是解析该过程的基础,对指导区域抗旱减灾具有重要实践意义。基于淮北平原两季夏大豆盆栽受旱试验,分别构建了收获时植株地上部生物量与籽粒产量之间、受旱当期和受旱后复水各生育阶段蒸发蒸腾量与同期地上部生物积累量之间的函数关系,并对不同阶段受旱胁迫下的产量构成要素响应进行了定量分析。结果表明,不同受旱胁迫下大豆收获时地上部生物量与籽粒产量之间均呈显著正相关(2015、2016季相关系数分别为0.91和0.78),籽粒产量与各阶段不断积累的地上部总生物量存在定量转化;大豆某一生育阶段受旱当期的蒸发蒸腾量与该阶段的地上部生物积累量呈显著正相关,且在花荚期更为明显;某一阶段受旱对后续各生育阶段的蒸发蒸腾与地上部生长均产生影响,且两者具有一定的相关性,但距受旱时期越远相关性越弱;大豆在营养生长阶段受旱后复水,鼓粒期的地上部生长机制恢复正常,且这种恢复效应在前期轻度受旱后更为明显;不同阶段受旱造成的籽粒产量损失差异较大,与充分灌溉相比,大豆分别在苗期、分枝期、花荚期和鼓粒期遭受干旱时,2015季和2016季的籽粒产量分别减少了14.2%和28.0%、18.2%和30.5%、53.1%和56.2%、50.1%和45.2%,花荚期和鼓粒期受旱对籽粒形成的不利影响更为严重;两季鼓粒期受旱胁迫下的收获时地上部生物量和千粒重均为最低。

There are a lot of uncertainties in the formation process of agricultural drought loss,while the quantitative response relationships between crop evapotranspiration and growth matter accumulation under different drought stress are the basis for analyzing the process,which has important practical significance for guiding regional drought resistance and disaster reduction.Based on the pot drought experiments of two-season summer soybean in the Huaibei Plain,the functional relationships between aboveground biomass at harvest and grain yield,and those between evapotranspiration and aboveground biomass accumulation at each growth stage of soybean during and after drought stress are established,respectively.In addition,the responses of yield components to drought stress at different stages are analyzed quantitatively.The results showed that there is a significant positive correlation between soybean aboveground biomass at harvest and grain yield(the correlation coefficients in 2015 and 2016 seasons are 0.91 and 0.78,respectively),and there is a quantitative transformation between grain yield and the total aboveground biomass accumulated during each stage.Moreover,there is a significant positive correlation between evapotranspiration and aboveground biomass accumulation at a certain stage of drought,and it is more obvious during the flowering-podding stage.In addition,drought stress at a certain stage also affects the evapotranspiration and aboveground growth during each growth stage after drought,and there is a certain correlation between these two,but the farther from the stage of drought,the weaker the correlation is.Furthermore,rewatering after drought during the vegetative growth phase,the growth mechanism of soybean returns to normal at the seed filling stage,and this recovery effect is more significant after slight drought.The grain yield losses caused by drought stress at various stages are quite different.Compared with full irrigation,the grain yield in 2015 and 2016 seasons decrease by 14.2%and 28.0%,18.2%and 30.5%,53.1%and 56.2%,50.1%and 45.2%,respectively,during the seedling stage,branching stage,flowering-podding stage and seed filling stage.The adverse effects of drought on grain formation at the flowering-podding stage and seed filling stage are more serious.Moreover,the aboveground biomass at harvest and 1000 grain weight are both the lowest under drought stress at the seed filling stage in the two seasons.