Crop improvement of Bambara groundnut through mutation breeding

Abstract

Bambara groundnut is an important indigenous African grain legume cultivated primarily by smallholder farmers across sub-Saharan Africa. The crop is valued for its nutritional richness, adaptability to marginal environments, and contribution to household food security and soil fertility through biological nitrogen fixation. Despite these advantages, Bambara groundnut (BG) remains underutilized and under-researched, with productivity constrained by low yield potential, asynchronous pod development, long maturity periods, susceptibility to environmental stresses, and limited availability of improved cultivars. Furthermore, the relatively narrow genetic base of cultivated germplasm restricts progress through conventional breeding approaches. Mutation breeding provides an opportunity to generate novel genetic variation beyond that available in existing germplasm; however, its application in BG remains limited, with relatively few studies reporting the development and evaluation of mutant populations. This review critically examines the current status of mutation breeding research in BG and evaluates its potential for accelerating genetic improvement of the crop. Particular attention is given to the use of induced mutagenesis for enhancing agronomic performance, seed quality traits, and tolerance to biotic and abiotic stresses. The review further highlights major research gaps, including the limited number of well-characterized mutant populations, inadequate multi-environment validation of mutant lines, and the lack of integration between mutagenesis and modern breeding technologies. In addition, the potential role of genomics, transcriptomics, metabolomics, proteomics, and high-throughput phenotyping in enhancing the identification and characterization of beneficial mutations is discussed. Future research should prioritize the development of large mutant populations, standardized mutagenesis protocols, and the integration of multi-omics and advanced phenotyping approaches to accelerate the generation of superior BG varieties. Such efforts could expand the genetic diversity available for BG improvement, enhance breeding efficiency, and strengthen its contribution to sustainable agriculture, climate resilience and food and nutritional security.