CROP WILD RELATIVES OF LEGUME PULSES: AN UNTAPPED RESOURCES IN INSECT RESISTANCE BREEDING

Abstract

Legume pulses are essential to ensuring food and nutritional security around the world, but remain subject to significant losses due to insects in the field and during storage. Due to domestication bottlenecks, genetic erosion and the loss of defence related traits, resistance remains limited in cultivated legumes and this makes them increasingly susceptible to the challenges posed by a changing climate. Wild legume relatives serve as important reservoirs of resistance to insect pests, and adaptive genetic variation created over time through a dynamic co evolutionary process with insect enemies. This review brings together ecological, evolutionary, physiological, biochemical, and molecular understanding of resistance mechanisms found in wild legume taxa, which could help improve insect resistance in legumes. Such wild relatives are endowed with a variety of defense mechanisms: structural barriers, secondary metabolites, defense proteins and defense hormones, as well as with various inducible defense mechanisms. Advances in genomic and multi-omics platforms have made it possible to pinpoint resistance loci, candidate genes, and defense-related pathways with direct applications in crop improvement. However, limitations in the use of these are still faced due to reproductive barriers, linkage drag, less genomic resources and small germplasm characterization. A combination of systematic germplasm exploration, standardized phenotyping, and the application of omics-assisted breeding approaches will be essential for developing pest and disease resistant pulse cultivars, ultimately supporting the goal of reduced or eliminated chemical pesticide use in sustainable pulse production systems.