Breeding rice varieties for abiotic stress tolerance: Challenges and opportunities

Abstract

Climate change-induced abiotic stresses are considered as notable threat to world food security affecting crop, livestock, and fisheries production which are all fundamental for sustainable development of human life. Impact of climate variability affecting water availability, nutrient levels, soil moisture, temperature, and tropical ozone in crop yield is measured in various studies. Rice, the critical crop in maintaining food security, has high vulnerability to increased frequency and intensity of extreme weather events which affects crop growth at macro- and microenvironment. Meanwhile, rising temperatures and consequent rise in sea level can make farming riskier by increasing salinity in the cultivatable lands. Decrease in productivity of rice is mainly related to extreme environmental conditions such as water deficit, high temperature, submergence, salinity, cold, and accumulation of heavy metals apart from higher incidence of pathogens and pests. Crop germplasm, wild relatives, and other species serve as main genetic sources for tolerance. These can be useful in crop breeding as they have had adaptation and acclimation responses developed through natural selection process. Hence, identification of genetic loci, mechanism, and signaling path ways provides a paradigm to improve yield under diverse ecosystem. By using marker- assisted selection, beneficial alleles from wild relatives can be introgressed to develop climate-ready rice varieties.