Climate Change and Heat Stress Tolerance in Chickpea

Chickpea (Cicer arietinum L.) is a cool-season food legume and suffers heavy yield losses when exposed to heat stress at the reproductive (flowering and podding) stage. Heat stress is increasingly becoming a severe constraint to chickpea production due to the changing scenario of chickpea cultivation and expected overall increase in global temperatures due to climate change. A temperature of 35 °C was found to be critical in differentiating heat-tolerant and heat-sensitive genotypes in chickpea under field conditions. Large genetic variations exist in chickpea for reproductive-stage heat tolerance. Many heat-tolerant genotypes have been identified through screening of germplasm/breeding lines under heat stress conditions in the field. A heat-tolerant breeding line ICCV 92944 has been released in two countries (as Yezin 6 in Myanmar and JG 14 in India) and is performing well under late-sown conditions. Heat stress during the reproductive phase adversely affects pollen viability, fertilization, pod set, and seed development, leading to abscission of flowers and pods, and substantial losses in grain yield. Studies on physiological mechanisms and genetics of heat tolerance, and identification of molecular markers and candidate genes for heat tolerance, are in progress. The information generated from these studies will help in developing effective and efficient breeding strategies for heat tolerance. The precision and efficiency of breeding programs for improving heat tolerance can be enhanced by integrating novel approaches, such as marker-assisted selection, rapid generation turnover, and gametophytic selection. Chickpea cultivars with enhanced heat tolerance will minimize yield losses in cropping systems/growing conditions where the crop is exposed to heat stress at the reproductive stage.