Utilization of Plant Genetic Resources of Bambara Groundnut Conserved Ex Situ and Genetic Diversification of Its Primary Genepool for Semi-Arid Production

Bambara groundnut (Vigna subterranea (L.) Verdc) is a nutritious and drought-tolerant crop that is native to Africa. Currently, it possesses a cosmopolitan distribution across the semi-arid agro-ecologies of Africa and its cultivation has extended to other regions, particularly in the drier parts of Asia and Indonesia. Due to historic neglect, research on the crop and policy prioritization in national breeding programs is lagging; hence, varietal development is in its infancy. Farmers rely on traditional landraces, which are characterized by low productivity and yield. Breeding for moisture stress adaptation and high yield is crucial to improve its productivity and adequate genetic diversity is desired to strengthen resiliency for climate adaptation and nutritional and food security. Nevertheless, thousands of plant genetic resources (PGRs) conserved in several genebanks are still not being fully utilized to reintroduce lost diversity into farmers' fields and pre-breeding activities. The exploitation of ex situ conserved PGRs has been minimal due to a lack of extensive genetic characterization. Thus, to harness utilization of the PGRs in genetic improvement programs, holistic strategies including the traditional genomic resources and participatory-led trait discoveries are needed to bridge the gap between conservation and utilization of ex situ germplasm. This review focuses on the PGRs of bambara, methods to widen genetic diversity, genomic resources, and high-throughput phenotyping to enhance the utilization of genetic resources in pre-breeding programs, and approaches to identify useful adaptive features for yield and drought.