Effects of low temperature on japonica rice quality in China: A meta-analysis

Abstract To investigate the effect of low temperature on the quality of japonica rice, the literature published in the last 20 years (2005-2024) was collected and a database of japonica rice quality was established. Meta-analysis was used to quantify the effect of low temperature on the quality of japonica rice in China under different conditions at the late reproductive stage. The sensitivity of japonica rice to low temperature decreased in the following order: appearance quality > eating quality > milling quality. The effects of low temperature degree (∆T) on japonica rice quality differed. When 3°C6°C, the chalkiness (23.69%) greatly increased, the brown rice percentage (-3.46%) decreased, the milling quality and appearance quality reached their lowest values. Low temperature occurred in different development stages, with small differences in the degree of low temperatures, had variable effects on rice quality traits. Low temperature was most sensitive before and during grouting and significantly reduced the quality of japonica rice. In the single-double-cropping areas of Central China, the low temperature of 19.7°C averaged at the filling stage after delayed sowing improved the milling and appearance quality. However, low temperatures in the early single-cropping area in Northeast China, single-cropping area in North China and single-double-cropping area in Southwest China reduced the milling and appearance quality, improved the eating quality. Our findings provide important insights for the quantitative simulation and prediction of japonica rice quality under future climate change scenarios.