中文摘要：

全球气候变暖并不是白天和夜间的平均变暖,而是呈现一定的不对称性。大豆（Glycine max）是世界范围内种植较广泛的豆科作物,也是中国重要的粮食作物。研究大豆的生长与水分利用对不对称性气候变暖的响应,可为预测未来气候变暖情景下大豆的适应提供科学的参考依据。该实验在人工气候箱中采用盆栽方式进行,设立对照（CON,昼26℃夜16℃）、对称性升温（ETs,昼夜均升高3℃）和不对称性升温（ETa,昼升高2℃,夜升高4℃）三个温度情景,研究了大豆产量和水分利用对昼夜不对称性与对称性升温的差异性响应。结果表明：在昼/夜26℃/16℃的背景下,1）ETs对大豆产量影响不显著,主要是因为生物量的增加缓解了收获指数下降对大豆的不利影响;ETa使大豆产量减少38.9%,是由于大豆的收获指数和产量构成要素（荚数、粒数、百粒重）均显著降低。2）ETs对大豆全生育期蒸散量（ET）的影响不显著,ETa使大豆整个生育期ET减少14.8%。3）两种升温模式对大豆耗水量中蒸发量的影响都不显著,耗水量的差异主要来自蒸腾量的差异,其中ETs和ETa分别使大豆全生育期蒸腾量降低10.7%和26.1%。综上所述,只针对ETs进行研究,而没有对ETa进行研究的实验会低估真正的气候变暖情景（ETa）对大豆生长和产量的不利影响,高估其对大豆耗水量的影响。

英文摘要：

Aims Global warming does not mean similar warmer temperatures between daytime and nighttime. Soybean （Glycine max） is a widely planted legume crop around the world and an important food crop in China. The aim of this study was to understand the responses of soybean growth and water utilization to future asymmetric warming, which would provide scientific reference for evaluating the adaptation of soybean to the future climate scenarios. Methods This experiment was carried out in artificial climate chambers, using the method of potted plants, under three temperature conditions; contrast （CON, 26 ℃ during the day and 16℃ during night）, symmetric warming （ETs, elevated temperature of 3℃ both during the day and night）, asymmetric warming （ETa, elevated temperature of 2℃ during the day and elevated temperature of 4℃ during night）. We investigated the differential effects of diurnal asymmetric and symmetric warming on the yield and water consumption of soybean. Important findings The results revealed that, under the background of 26 ℃ during the day and 16 ℃ during night： 1） the effect of ETs on soybean yields showed no significant function that mainly benefit from the increase in the amount of biomass to ease negative influence of decrease in the harvest index. ETa reduced yields of soybean by 38.9% （p 〈 0.05） due to both significant decrease in harvest index and yield components （pod number per plant, grain number per pod and 100-grain weight）. 2） ETs showed no obvious effect on the whole growing stage evapotranspiration （ET） of soybean, while ETa reduced the whole growing stage ET by 14.8% （p 〈 0.05）. 3） The effect of the two warming pattern on water consumption of soybean were not significant. The difference in water consumption was mainly derived from the difference in transpiration （T）. ETs and ETa reduced total transpiration by 10.7% （p 〈 0.05） and 26.1% （p 〈 0.05）, respectively. In conclusion, our results suggest that ETs will underestimat