Genomics and physiological approaches for root trait breeding to improve drought tolerance in chickpea (Cicer arietinum L.)

Terminal drought stress is one of the most serious constraints in chickpea production in the semiarid tropics. Physiological and breeding studies have indicated that roots play an important role in conferring tolerance to drought in chickpea. As a result, root traits such as root depth, root length density, and root biomass are being targeted for understanding their genetics and extent of variation available in the germplasm collection. Efforts are also made for identifying molecular markers associated with different root traits responsible for conferring drought tolerance. In parallel, cDNA libraries are being generated from root tissues of chickpea exposed to drought stress in greenhouse as well as field conditions, and gene discovery experiments are underway. Molecular markers and candidate genes associated with root traits are being targeted to introgress the QTLs (quantitative trait loci) for root traits from drought-tolerant genotypes to drought-sensitive genotypes following marker-assisted breeding strategies. Thus, by combining genomics, physiology, and breeding, the development of drought-tolerant chickpea cultivars with higher yield in the semiarid tropics will be more effective and efficient