Study on breeding and cultivation strategies for winter rapeseed to cope with climate change in the lower reaches of the Yangtze River

Climate change has a significant impact on rapeseed production, making it essential to clarify breeding and management strategies under evolving climatic conditions to ensure production stability. To systematically investigate the relationships between meteorological factors and yield, oil yield, and resistance-related traits, multi-year and multi-location national trial data from major production areas in the lower reaches of the Yangtze River during 2009-2023 were analyzed using a mixed linear model (MLM), linear regression, and canonical correlation analysis. Results showed a significant increase in mean temperature during the rapeseed growing season in this region, accompanied by greater temperature fluctuations and increased precipitation variability. Overall, the rise in mean temperature was beneficial for improving yield and oil production; however, extreme weather events substantially weakened this positive effect, and low temperatures in November had a particularly negative impact on yield. Canonical correlation analysis revealed two dominant meteorology-trait coupling patterns: Type 1 (humid late autumn-moderately cool early spring-moderately warm late spring), which supported safe overwintering, strong regrowth, and effective disease control, thereby significantly boosting yield but potentially reducing oil content; and Type 2 (cold spring), which was associated with suppressed yield and structural traits, as well as increased disease risk. It is recommended to enhance monitoring and early warning systems for extreme weather, especially low temperatures in November, and to adopt targeted management strategies. Under different climatic scenarios, differentiated field practices and a “dual-target” breeding strategy should be implemented: in warm and moist favorable years, optimize planting density and nutrient management to enhance oil content and thousand-seed weight; in cold spring years, apply timely control measures for Sclerotinia sclerotiorum rot and reinforce nutrient supply during the flowering to maturity stages. Breeding efforts should focus simultaneously on developing high-yield, disease-resistant genotypes and high-oil, high-thousand-seed-weight genotypes to enhance adaptability under complex climate conditions. A multidimensional meteorology-trait-yield early warning system should be established, integrating historical climate patterns with future projections to enable dynamic optimization of cultivar selection and field management.