Effects of Low Temperature on Growth and Yield of Japonica Rice at Different Periods of Grain-filling Stage in Cold Regions
In order to explore the effects of low temperature on growth and yield of rice at different periods of grain-filling stage in cold regions,four high-quality Japonica varieties were used as materials.Low temperature treatments(day/night,17℃/13℃)were set at 7-13 d,14-20 d and 21-27 d after flowering,respectively,with outdoor normal temperature planting as the control.The SPAD values of flag leaves,antioxidant enzyme activity,dry matter accumulation,panicle traits and yield of rice were determined.The results showed that there were some differences in physiological and yield among different varieties,and the responses of that to low temperature were also different.Compared with control,the SPAD values of flag leaves were significantly increased by 7.74%-13.49%,20.09%-33.17%and 29.65%-52.36%under low temperature at different periods of grain-filling stage,respectively.Low temperature generally increased the antioxidant enzyme activity of flag leaves,and the effect in the early stage was higher than that in the later stage.The panicle dry matter weight of the four varieties was significantly reduced by 28.48%,35.44%,33.51%and 33.30%,respectively,under low temperature stress in the early stage,and the stem dry matter weight was less affected by low temperature.The effects of low temperature on the secondary branches were higher than those on the primary branches.The grain number per panicle,1 000-grain weight and seed setting rate of the primary and secondary branches were reduced to varying degrees,which decreased the rice yield(0.35%-17.49%).The results of this research can provide a theoretical reference for the study of cold tolerance physiology of Japonica rice in cold regions.
Japonica ricegrowthyieldgrain-filling stagelow temperature
万方数据
维普
