Breeding for Climate Resilient Cotton Varieties: Present Status and Future Prospects

Global warming and its impact on climate change pose serious threat to agriculture, leading to fall in global production. Climate change-induced elevated temperatures, CO2, and irregular rainfall distribution patterns cause abiotic stresses that include drought, heat stress, waterlogging, salinity and elevated CO2. Cotton (Gossypium spp.), an economically important fiber crop, is adversely affected by global warming. This review aims to provide an outlook on the physiological and biochemical impacts of climate change on cotton production and breeding approaches to develop climate-resilient genotypes. Heat stress affects cotton throughout its life cycle, especially during the reproductive stage by hindering boll formation and boll retention. It reduces photosynthetic efficiency by inactivating the enzymes Rubisco and Rubisco activase, degrading chlorophyll, damaging Photosystem II, and destabilizing thylakoid membranes. Waterlogging, due to erratic rainfall, and poor drainage, creates a hypoxic state in the root zone. This condition weakens root function, limits nutrient uptake, and leads to oxidative damage, thereby reducing plant growth and productivity. In contrast, elevated CO₂ enhances the photosynthetic rate in cotton. This condition makes cotton susceptible to biotic stresses due to the inactivation of defense mechanisms. Salinity causes various physiological and biochemical imbalances in cotton affecting the crop morphology, plant stand, yield and fiber quality. Addressing the interactive effects of stresses is essential for developing climate-resilient genotypes.