Climate Change and Heat Stress Tolerance in Chickpea

Abstract

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.

Recent breeding programs enhanced genetic diversity in both desi and kabuli varieties of chickpea (Cicer arietinum L.)

“…CNV for two genes Ca_23345 and Ca_11443 that encode disease resistance were present only in CDC Luna variety, which is resistant to AB. Given the importance of early maturity, owing to large shift (~30% of total chickpea area) from cooler long season to short warmer season environments and increasing incidence of reproductive heat stress20, varieties like ICCV 92318, ICCV 92337, ICCV 95334 and ICCV 92311 were developed using ICCV 2 (carrying early flowering gene efl 1 of known allelic relationship). Major flowering time QTLs were reported on the Ca4 using ICCV 232, similarly Varshney and colleagues33 also reported on the Ca4 using ICC 4958.…”

“…Over 350 chickpea varieties with desirable traits like early maturity, tolerance to stresses, have been released globally20. Understanding the diversity at genome level in case of the varieties will enable utilization of alleles gained or lost over decadal periods, to address the future challenges and develop climate smart and resilient chickpea varieties.…”

Impact of High Temperature and Drought Stresses on Chickpea Production

“…Drought and high temperature stresses are the most important constraints among climate events. It is estimated that 50% of yield losses are caused by drought and heat stresses [6]. Chickpea is largely grown as a rotation crop in the cereal cropping system on residual soil moisture.…”

Genotypic variation in soil water use and root distribution and their implications for drought tolerance in chickpea

“…Drought causes substantial annual yield losses up to 50% in chickpea, which equals to a loss of US $ 900 million, and the productivity remained constant for the past six decades (Ryan 1997;Ahmad et al 2005;Bantilan et al 2014). With the changing climate scenarios and continuous population explosion, there is a great need to develop high-yielding chickpea varieties with improved drought tolerance (Evans 1998;Gaur et al 2014). Improvements of chickpea yields under DS have been achieved, mostly by breeding short duration cultivar that mature before the water deficit becomes too severe (Kumar et al 1985;Kumar and Rao 2001) with an often observed penalty in grain yield due to underutilisation of the available growing season.…”