Meta-analysis and dose–response analysis of low-temperature stress effects on rice yield and physiological responses

Low-temperature stress is a major environmental constraint on rice yield stability, considerable variation remains in the reported direction and magnitude of these effects. In this study, we conducted a systematic meta-analysis combined with dose–response analysis to evaluate the effects of low-temperature stress on rice yield formation, photosynthetic capacity, and physiological responses. The results showed that low-temperature stress significantly reduced yield-related traits in rice, with yield per plant and pollen viability decreasing by 10.58% and 21.75%, respectively. Photosynthetic performance was also markedly affected, as net photosynthetic rate (Pn), transpiration rate (Tr), and stomatal conductance (Gs) decreased by 26.67%, 10.93%, and 31.00%, respectively, while intercellular CO 2 concentration (Ci) increased by 5.75%. Low-temperature stress also significantly induced the accumulation of osmotic regulatory substances and aggravated oxidative damage. Subgroup analysis and meta-regression indicated that the effects of low-temperature stress were jointly regulated by growth stage, stress temperature, and stress duration. Specifically, yield responses were more sensitive at the booting stage and heading–flowering stage, while Pn showed more pronounced responses to severe low temperature and prolonged stress. Dose–response analysis showed that most traits exhibited response turning points around 24 °C. Overall, this study quantitatively revealed the associations among yield reduction, photosynthetic inhibition, and physiological homeostasis imbalance in rice under low-temperature stress, providing comprehensive evidence for understanding the response patterns of rice to low temperature.