Salinity Tolerance in Legumes: Classical and Molecular Breeding Perspectives

Abstract

Legumes, essential for global nutrition, confront challenges like environmental stresses like extreme temperatures, drought, and salinity. Salinity, affecting 8.7% of the planet’s area, poses a severe threat to legume cultivation, impacting physiological functions, nutrient balance, and nitrogen fixation. This chapter comprehensively explores the complex responses of legumes to salt stress, highlighting adaptive mechanisms such as osmotic stress tolerance, ion exclusion, antioxidant regulation, and hormone modulation. The breeding strategies, including molecular techniques like QTL mapping, association mapping, and transgenics, offer promising solutions to enhance salt tolerance in legumes. The knowledge regarding salt tolerance breeding is well-documented in cereals but not in legumes, emphasizing the identification of genomic regions associated with tolerance and the effective utilization of molecular tools. Wild relatives provide valuable tolerance genes, requiring detailed understanding of their roles at different developmental stages. The multi-environment screening and integration of diverse breeding approaches, including genomics, transcriptomics, metabolomics, transgenics, and CRISPR-Cas9, is essential for developing legumes capable of thriving in saline environments and exhibiting high-salt tolerance.