Increased ranking change in wheat breeding under climate change

Area of Science:

• Agricultural Science
• Plant Breeding
• Climate Change Adaptation

Background:

• The International Maize and Wheat Improvement Center (CIMMYT) distributes elite wheat lines globally for breeding and variety release.
• Collaborator test sites face climate change, impacting wheat genotype breeding and selection strategies.
• Understanding genotype-environment interactions is crucial for adapting wheat to diverse and changing conditions.

Purpose of the Study:

• To analyze changes in genotype-environment interactions in CIMMYT global spring wheat trials over recent decades.
• To investigate the impact of climatic factors on wheat yield and cultivar performance ranking.
• To assess how genetic improvement and breeding strategies interact with climate change effects.

Main Methods:

• Utilized a standard quantitative genetic model to analyze four CIMMYT global spring wheat trial datasets (1980-2018).
• Examined crossover interactions as a key indicator of changes in cultivar performance ranking across environments.
• Quantified the influence of climatic factors on year-to-year variability in crossover interactions for yield.

Main Results:

• Crossover interactions, indicating shifts in cultivar performance ranking, have significantly increased over time.
• Climatic factors accounted for over 70% of the year-to-year variability in yield crossover interactions.
• Climate change increased ranking changes in favorable environments by ~15% but reduced them in heat/drought-stressed environments by up to 13%.
• Genetic improvement generally heightened crossover interactions, especially for high-yielding environments.
• New wheat germplasm bred for heat stress demonstrated enhanced adaptation and stability, mitigating some climate change impacts.

Conclusions:

• Climate change is demonstrably altering genotype-environment interactions in wheat breeding, necessitating adaptive strategies.
• While breeding for favorable environments has seen increased ranking instability, targeted heat/drought stress breeding shows greater resilience.
• Recent advancements in heat-stress-adapted wheat germplasm offer promising stability under warming climates, highlighting the potential for climate-resilient crop development.