Potential and limits of exploitation of crop wild relatives for pea, lentil, and chickpea improvement

Abstract

Legumes represent the second most important family of crop plants after grasses, accounting for approximately 27% of the world's crop production. Past domestication processes resulted in a high degree of relatedness between modern varieties of crops, leading to a narrower genetic base of cultivated germplasm prone to pests and diseases. Crop wild relatives (CWRs) harbor genetic diversity tested by natural selection in a range of environments. To fully understand and exploit local adaptation in CWR, studies in geographical centers of origin combining ecology, physiology, and genetics are needed. With the advent of modern genomics and computation, combined with systematic phenotyping, it is feasible to revisit wild accessions and landraces and prioritize their use for breeding, providing sources of disease resistances; tolerances of drought, heat, frost, and salinity abiotic stresses; nutrient densities across major and minor elements; and food quality traits. Establishment of hybrid populations with CWRs gives breeders a considerable benefit of a prebreeding tool for identifying and harnessing wild alleles and provides extremely valuable long-term resources. There is a need of further collecting and both ex situ and in situ conservation of CWR diversity of these taxa in the face of habitat loss and degradation and climate change. In this review, we focus on three legume crops domesticated in the Fertile Crescent, pea, chickpea, and lentil, and summarize the current state and potential of their respective CWR taxa for crop improvement.

Wild and Domestic Differences in Plant Development and Responses to Water Deficit in Cicer

“…Given genetic bottlenecks in most crop species, there is widespread interest in exploiting crop wild relatives (CWRs) that typically harbor much greater diversity (Tanksley and McCouch, 1997;Dempewolf et al, 2014;Gepts, 2014). Advocates of base broadening suggest that the greater genetic diversity of CWR will improve complex traits like yield by breaking linkage drag through the introgression of novel, previously unexploited alleles (Tanksley and McCouch, 1997), and/or be reflected in greater adaptive diversity (Dempewolf et al, 2017;Coyne et al, 2020). Indeed, ideas such as exploiting the climatic resilience of wild populations have gained considerable traction recently (McCouch et al, 2013;Dempewolf et al, 2014).…”

Editorial: Wild Plants as Source of New Crops

“…Crop wild relatives (CWRs) remain the largest reservoir of genetic diversity for crop improvement and have been utilized for major gene disease and pest resistance, and abiotic stress tolerance ( Vavilov et al., 1992 ; Hajjar and Hodgkin, 2007 ; Warschefsky et al., 2014 ; Castañeda-Álvarez et al., 2016 ; Smýkal et al., 2018 ; Coyne et al., 2020 ). However, there remains a large set of plant species from various plant families and genera which have favorable traits but have not been domesticated so far.…”

The Impact of Domestication on Aboveground and Belowground Trait Responses to Nitrogen Fertilization in Wild and Cultivated Genotypes of Chickpea (Cicer sp.)

“…The genetic bottlenecks that arise from domestication, post-domestication divergence, and the intensive breeding for agronomic traits may have additional, inadvertent effects on unselected belowground traits (e.g., Morrell et al, 2013;Gaut et al, 2018). These inadvertent effects are one of several reasons why large collections of wild relatives with a greater range of adaptive traits or plasticity than in the cultigen are needed in breeding programs to increase the resilience of our crops within a changing global climate (Warschefsky et al, 2014;Coyne et al, 2020).…”