Identification method for heat resistance of rice based on accumulated hourly temperature
[Objective]The relationship between accumulated hourly temperature and spikelet fertility rate was studied to explore evaluation method for rice heat resistance,in order to provide reference for identification and breeding of new heat-tolerant rice varieties.[Method]Using super rice Guiliangyou 2,high-quality hybrid rice Liangfengyou 339,and heat-resistant rice variety N22 as materials,the pot experiments were conducted in phytotron by setting different stress temperatures(35 and 38 ℃) and continuous stress times(2,4,6,8,10 d),resulting in generating different accumulated hourly temperatures,and the spikelet fertility rate was determined using real-time heading panicle label method under different heat-stress treatments,with relative spikelet fertility rate in natural environment as CK.[Result]The results showed that,the spikelet fertility rate of all rice varieties decreased gradually with increase of heat stress.Taking 32℃ as heat-stress temperature threshold,there was a negative exponential relationship between accumulated hourly temperature and relative spikelet fertility rate(Y=116.7e-0.01x,r2=0.84*,P＜0.05).When the relative spikelet fertility rate was 50％,the calculated accumulated hourly temperature was 85 ℃.h,and the corresponding temperature-stress treatments were at 35 ℃ for 5 continuous days or 38 ℃ for 3 continuous days,resulting in actual accumulated hourly temperature up to 90 ℃oh.[Conclusion]Pot experiments can be conducted in phytotron with natural lighting and relative humidity of 80％,the rice plants are treated with temperature-stress of 38 ℃ for 3 continuous days from 9:30 to 15:30 per day,with accumulated hourly temperature of 90 ℃·h,using rice plants in natural environment as CK,then the relative spikelet fertility rate is calculated.Therefore,the evaluation method for rice heat resistance is scientific and effective with relative spikelet fertility rate as evaluation index.
国家科技期刊平台
NSTL
万方数据
维普
