Meta-analysis and dose-response analysis of high temperature effects on rice yield and quality

Abstract Global warming is one of the biggest challenges for improving the productivity of rice crops in the future. In this study, a meta-analysis and a dose-response analysis were conducted with data collected from 95 publications to study the differential responses of physiological traits, yield components, and grain quality to high day and night temperatures in rice. Overall, grain yield was reduced by 39.6% (with 95% CI from −42.9% to −35.6%) under high temperatures, which was primarily caused by the decrease of seed set percentage. Yield reductions caused by high temperatures were associated with a decrease in photosynthesis and an increase in respiration. High temperatures affected grain quality by decreasing head rice percentage and increasing chalky rice rate and chalkiness. The reduction of grain yields under high day temperature was primarily caused by the reduction in seed set percentage. However, under high night temperature, the combination of decreased spikelet number per panicle, grain weight, and biomass production in addition to decreased seed set percentage contributed to the decline of grain yields. These results suggest that the differential effects of day and night warming on the processes that contribute to formation of rice yield should be considered when new rice cultivars are developed as a crop adaptation strategy for future global warming.