Differential Effects Of Diurnal Asymmetric And Symmetric Warming On Yield And Water Utilization Of Soybean (Glycine Max L. Merr)

Global warming has become an indisputable fact, and global warming is not average warming and exist obvious asymmetry in day and night, the lowest increased temperature amplitude is greater than the growth rate of daily maximum temperature, At present, the research of the impact of crop growth on asymmetry and symmetry in day and night has become the contemporary scientific community urgently needs that is one of the hot issues to solve.Soybean is relatively broad bean crops around the world, and the important food crops in China. climate warming changes a series of physiological changes in the soybean growth season, which eventually changes the soybean yield and water use efficiency. Facing the situation of global warming, Studying different effect of asymmetric and symmetric warming on plant production and water use efficiency of soybean in day and night can make a reasonable response and management measures In the climate situation of future and provide certain science reference to improve yield and water use efficiency of soybean plant.Global warming does not mean average warmer temperatures between daytime and nighttime. Soybean is a widely planted legume crop in 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 the adaptation of soybean to the future climate scenarios. This experiment was carried out in artificial climate chambers, using the methed 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.The results showed that under the background of 26? during the day and 16? during night:This experiment adopts the potted manner in the artificial climate box, the three artificial climate box set respectively the three different temperature, its respectively set up a control(CON, 16 ?night and day26 ?)?symmetry temperature(ETs, day and night rise 3 ?) and the asymmetry of temperature(ETa, day rise 2 ?, the night rise 4 ?), this experiment put small basin in the artificial climate box for soybean planting, three artificial climate box each place eighteen small basins respectively and two seeds and put an empty pot in each climate box,the experiment used to measure the soil evaporation and transpiration,in the process of test, the artificial climate box maintained no insect pests and weeds, at the same time, the soybean seedlings water a nutrient solution in a while starting from the experiment planted soybean seeds to the mature,The difference effects of the soybeanyield and water use of asymmetry and symmetry in day and night been studied form the soybean plant to the harvest. The results showed that :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 evapotranspiration(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.4?the yield of soybean protein, fat, starch nutrient was reduced under ETs and ETa scenario, and the ETa nutrient yield decreased more than ETs situations.In conclusion, the results of the present study indicate that symmetric warming(ETs) will underestimate the detrimental effects of real climate warming(ETa) on the growth and yield of soybean, and overestimate the effects on water consumption of soybean.