Modelling the advancement of chilling tolerance breeding in Northeast China

Abstract

AbstractDespite 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 high‐yielding 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.