Plant breeding is needed to meet agroecological requirements: Legume crops as case study

Legume-based cropping systems are regaining interest due to the environmental services and the variety of food and feed uses they provide, this having special interest in agroecological systems. There are many legume crops that can be adopted but focused breeding is needed to better meet the specific requirements of each system, especially in the situation of changing climate and often stressful environments. Standard breeding methods remain valid, from classical selection, to genomic assisted-breeding, profiting from the modern biotechnological and genomic approaches which are rapidly developing for most legume crops. Rather than focusing on the tools, emphasis is needed on the breeding targets, which might be different from those of high input agriculture such as improved response to symbiosis, nutrient and water use efficiency and tolerance to biotic and abiotic stresses becoming priorities. Breeding for these traits requires the infusion of genetic diversity from landraces or wild relatives by pre-breeding. Prospects and constraints are discussed.