Management and breeding for rust resistance in legumes

Abstract

Rust diseases are a major concern in legume production worldwide causing heavy losses especially in developing countries that depend on grain legumes as staple food. Fungal species from Uromyces, Phakopsora and Puccinia genera are the main causal agents of the various legume rust diseases. They induce up to 100% yield losses on susceptible cultivars and are emerging as a substantial threat to global food security. Developing durable resistance to rust has thus become a critical breeding objective alongside efforts to improve cultural and disease management practices. This review specifically focuses on the recent advances in understanding and enhancing genetic rust resistance across diverse legume crops. Key topics covered include: (i) the diversity and host range of the rust species affecting legumes; (ii) the disease management strategies from cultural practices to chemical control; (iii) the available screening methods for identifying new sources of resistance; (iv) the genetic basis of resistance, encompassing both major resistance genes and quantitative trait loci; (v) insights into gene regulation and effector molecules leading to legume-rust interactions; and (vi) emerging genomic-assisted breeding techniques that can accelerate the development of durable rust resistance in legumes. Overall, this review highlights the progress made to date and the remaining challenges in sustainably managing rust diseases across diverse legume crops through integrated approaches spanning pathogen biology, advanced phenotyping, genetic resistance, and molecular breeding.