结实期不同时段低温对粳稻生长发育和产量的影响

Effects of Low Temperature on Growth and Yield of Japonica Rice at Different Periods of Grain-filling Stage in Cold Regions

为探索结实期不同时段低温对粳稻生长发育和产量的影响,试验以4份优质粳稻品种为试材,在开花后7~13、14~20、21~27 d分别进行低温处理(昼/夜:17℃/13℃),以室外常温种植为对照,测定水稻剑叶的SPAD值、抗氧化物酶活性、干物质积累量、穗部性状及产量。结果表明:不同品种生理和产量性状存在一定差异,同时对结实期低温的响应也不同。结实前、中、后期低温处理后,剑叶的SPAD值较对照分别显著增加7.74%~13.49%、20.09%~33.17%,29.65%~52.36%。低温总体上提高了剑叶的抗氧化物酶活性,且前期低温对其影响高于后期。前期低温处理后4个品种的穗干物质重分别显著降低28.48%、35.44%、33.51%、33.30%,茎干物质重受低温影响较小。低温胁迫对二次枝梗的影响高于一次枝梗,均不同程度降低一、二次枝梗的穗粒数、千粒重和结实率,最终降低水稻产量(0.35%~17.49%)。研究结果可为寒地粳稻耐冷生理研究提供理论参考。

In order to explore the effects of low temperature on growth and yield of rice at different periods of grain-flling stage in cold regions,four high-quality Japonica varieties were used as materials.Low temperature treatments(day/night,17 C/13 C)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,1000-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.