Understanding patterns of abiotic and biotic stress resilience to unleash the potential of crop wild relatives for climate-smart legume breeding

Although new varieties are urgently needed for climate-smart legume production, legume breeding lags behind with cereals and underutilizes wild relatives. This paper provides insights in patterns of abiotic and biotic stress resilience of legume crops and wild relatives to enhance the use and conservation of these genetic resources for climate-smart legume breeding. We focus onVigna, a pantropical genus with more than 88 taxa including important crops such as cowpea and mung bean. Sources of pest and disease resistance occur in more than 50 percent of theVignataxa, which were screened while sources of abiotic stress resilience occur in less than 20 percent of the taxa, which were screened. This difference suggests thatVignataxa co-evolve with pests and diseases while taxa are more conservative to adapt to climatic changes and salinization. Twenty-twoVignataxa are poorly conserved in genebanks or not at all. This germplasm is not available for legume breeding and requires urgent germplasm collecting before these taxa extirpate on farm and in the wild.Vignataxa, which tolerate heat and drought stress are rare compared with taxa, which escape these stresses or tolerate salinity. These rareVignataxa should be prioritized for conservation and screening for multifunctional traits of combined abiotic and biotic stress resilience. The high presence of salinity tolerance compared with drought stress tolerance, suggests thatVignataxa are good at developing salt-tolerant traits compared with drought-tolerant traits.Vignataxa are therefore of high value for legume production in areas that suffer from salinization.