Harnessing the Potential of Pigeonpea Wild Relatives for Climate Change Resilience

Pigeonpea ( Cajanus cajan (L.) Millsp.) is one of the globally important pulse crops that is cultivated in different parts of the world in Asia, Africa, and the Caribbean islands. India, Myanmar, Tanzania, Malawi, Kenya, and Uganda are the major producers. The productivity of pigeonpea is affected by adverse weather conditions despite its wide adaptability to grow in diverse agroclimatic zones. The impact of global warming is multidimensional and leads to climate change in all ecologies. These changes induced a shift in the insect-pest dynamics besides buildup of population of harmful pathogens in the soil and cropping system beyond the threshold level and, therefore, poses serious threat to crop health and productivity. Climate changes warrants developing pigeonpea cultivars with increased plasticity and ameliorate climate resilience by infusing genes for biotic and abiotic stress tolerance from the germplasm and crop alien species. However, crop wild relatives were not utilized to the fullest potential in spite of their enormous potential to faceoff the challenges posed by climate change–induced biotic and abiotic stresses. Cross-incompatibility, very poor successes in crossing, low recovery of traits of interest, high linkage drag, agronomically inferior progenies with poor adaptability are some of the reasons for under exploitation of wild relatives in regular breeding programs. Availability of modern breeding, cyto-genetic, molecular, and genomic tools, including next-generation sequencing technology, can efficiently overcome the bottlenecks of alien gene transfer for deriving climate-resilient genotypes. Therefore, coordinated and focused multidisciplinary efforts are required to harness the full potential of wild relatives of pigeonpea. Various aspects ranging from breeding to genomics and biotechnological interventions for harnessing the potential of crop wild species for developing climate-resilient pigeonpea varieties are discussed.