Modelling the advancement of chilling tolerance breeding in Northeast China

Abstract

Despite global warming, chilling injury during the reproductive stage is still a severe climate stress in temperate rice production systems. Much work has been done on stress avoidance by altering sowing dates and cultivar maturation, but stress tolerance has received less attention. The lack of data to inform existing genetic differences in chilling tolerance impedes model-based investigations exploring this adaptation.Here, from multiple data sources, we composited control experiments of 25 major rice cultivars in Northeast China, which allows determining the genetic differences in chilling tolerance. The results suggest that newer released rice cultivars tend to resist stronger chilling than older cultivars, and there is a coexistence between highyielding and more chilling tolerance. By projecting the above statistical relationship to regional yield, our analysis indicates that the lower chilling sensitivity due to such breeding progress may reduce yield fluctuation by approximately 74% in the lousy harvest year since 1960. Our results also indicate that chilling exposure at booting and flowering not only results in sterility but also may impact grain filling. Our study highlights the quantified cultivar difference in chilling tolerance based on the existing rice genotypes that can support further simulation-driven studies on the genetic adaptation of chilling stress and improve the quantitative evaluation of cultivar chilling tolerance in crop improvement.

Transcriptome and Metabolome Analyses Reveal Ascorbic Acid Ameliorates Cold Tolerance in Rice Seedling Plants

“…Exposure to cold stress during the seedling, flowering, and grain-filling stages in rice was found to weaken the efficiency of light utilization in the leaves at these stages, lower the photosynthetic rate in rice leaves, inhibit the synthesis and transport of assimilates, affect the growth rate of rice, and cause an increase in the source/sink growth ratio, leading to a reduction in rice production [4]. Similar results were also found in other studies of rice subjected to cold stress at different growth stages [5,6]. The occurrence of late spring coldness during the rice seedling stage severely affects the safe production of rice.…”

Natural variation of codon repeats in COLD11 endows rice with chilling resilience

“…In recent years, the cultivation of rice, one of the most important food crops feeding nearly half of the world’s population, has been threatened by abnormal environmental temperatures (such as chilling) induced by global climate change ( 1 , 2 ). The bottleneck limiting rice-planting region expansion to northern areas with much lower yearly temperatures is the improvement of chilling tolerance for rice cultivars, because rice is sensitive to chilling and the ability to tolerate low temperature is pivotal for its survival.…”

An experimental study on the effects of intermittent chilling at different growth stages on rice yield in Northeast China

“…Cooling degree days is a comprehensive index that factors in both the duration and intensity of chilling (Shimono et al, 2007) and could reflect the dynamic effect of low temperature on crop yield and yield components (Shimono, 2011; Zhang et al, 2021). In this study, we found statistically significant correlations between grain yield per plant as well as spikelet fertility and CDD for the continuous and intermittent chilling treatments at the booting and flowering stages.…”