Toward Climate-Smart Rice Systems: Moving Beyond Cultivar Improvement.

Rice is one of the world's most important staple crops and a major source of agricultural methane emissions. Breeding strategies such as photosynthate allocation modification and biomass enhancement show potential, but their effectiveness is highly context dependent, shaped by water regimes and soil organic carbon levels. Cultivars effective under continuous flooding may fail, or even increase emissions, under optimized water regimes. This perspective argues for integrated strategies that combine cultivar improvement with water and organic matter management, microbiome regulation, and climate-resilient breeding to build climate-smart rice systems that ensure both yield stability and methane mitigation.