Crop Improvement strategies for Mitigation of Methane Emissions from Rice
Climate change and its effects on agriculture will impact global food security. Rice (Oryza sativa L.), the major staple crop of the world, is subjected to substantial environmental constraints and criticism because of its role in climate change; methane emission under irrigated ecosystem. Mitigation of methane is the way forward for sustainable and eco-friendly rice production. Limiting area and production of rice may not be a feasible option as majority of the Asian population depends on rice. An urgent and integrated research approach to understand the mechanisms and interactions involved in methane release through rice plant is required to design viable mitigation technologies. Genetics of methane emission must be studied in detail, along with agronomic and management practices to obtain the precise information to elucidate the inheritance of related traits. Crop improvement interventions are required to identify contributing traits to methane emission, with subsequent deployment in plant breeding. Identification of rice cultivars with high-yield levels and traits contributing to low methane production represents an economic approach. Focus of breeding needs a shift towards adaptation to new production systems that can sustain effects of climate change. Low methane emitting varieties suitable to water management practices are more promising. This can be manifested in simultaneous achievement of global food security and mitigation of emissions without radical changes in the agronomic practices for the rice ecosystem. In this Review, an account of methane emission studies from rice and impact of crop growth stages as well as traits are outlined. The genotypic variation reported in Oryza spp for methane emission and breeding approaches for development of low methane emitting varieties are discussed.