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Bambara groundnut [Vigna subterranea (L.) Verdc.] is an underutilised, protein-rich and self-pollinating legume that can withstand high temperature and drought stress and is mainly grown in semi-arid Africa. In order to dissect the complexity of drought resistance and to use genomic tools for yield enhancement of bambara groundnut in response to drought stress, yield-related and morphological traits under drought-stressed (DS) and well-watered (WW) conditions were evaluated in the F3 and F4 segregating generations derived from a cross between two genotypes selected from landraces S19-3 (originally from Namibia) and DodR (originally from Tanzania). Significant quantitative trait loci (QTLs) for shoot dry weight (SDW) were mapped on LG10 accounting for 15.5% of the phenotypic variation explanation (PVE) under well-watered conditions and a putative quantitative trait locus (QTL) for the same trait mapped on LG10 with reduced PVE (10.10%) under drought-stressed conditions in the F3 segregating population. Significant QTLs associated with the number of seeds per plant (NS), number of double-seeded pods per plant (NDP), seed weight per plant (SW) and pod weight per plant (PW) were mapped on LG4 (nearest marker: 4181663 and 4175954) with overlapping confidence intervals and explained 21.9%, 21.8%, 23.5% and 19.9% of the PVE, respectively, under well-watered conditions in the F4 population, which could be considered as the major QTL involved in the control of these traits. Seven consensus QTLs for yield-related and morphological traits were mapped on LG2, LG3, LG4, LG7A and LG10. The study provides fundamental knowledge of QTLs associated with yield-related and morphological traits under drought-stressed and well-watered conditions in bambara groundnut, which is also essential for yield improvement of bambara groundnut in response to drought stress.

Bambara groundnut has the potential to be used to contribute more the climate change ready agriculture. The requirement for nitrogen fixing, stress tolerant legumes is clear, particularly in low input agriculture. However, ensuring that existing negative traits are tackled and demand is stimulated through the development of markets and products still represents a challenge to making greater use of this legume. World agriculture is currently based on very limited numbers of crops, representing a significant risk to food supplies, particularly in the face of climate change which is expected to increase the frequency of extreme events. Minor and underutilised crops can help to develop a more resilient and nutritionally dense future agriculture. Bambara groundnut [Vigna subterranea (L.) Verdc.[, as a drought resistant, nitrogen-fixing, legume has a role to play. However, as with most underutilised crops, there are significant gaps in knowledge and also negative traits such as 'hard-to-cook' and 'photoperiod sensitivity to pod filling' associated with the crop which future breeding programmes and processing methods need to tackle, to allow it to make a significant contribution to the well-being of future generations. The current review assesses these factors and also considers what are the next steps towards realising the potential of this crop.

Underutilised species such as bambara groundnut (Vigna subterranea (L.) Verdc.) have the potential to contribute significantly to meeting food and nutritional needs worldwide. We evaluated phenotypic traits in twelve bambara groundnut genotypes from East, West and Southern Africa and Southeast Asia and two F2 bi-parental segregating populations derived from IITA-686 &times, Tiga Nicuru and S19-3 &times, DodR to determine phenotypic trait variation and their potential contribution to the development of improved crop varieties. All phenotypic traits in twelve genotypes were significantly influenced (p &lt, 0.01) by genotypes. Principal component analysis (PCA) showed that PC1 accounted for 97.33% variation and was associated with four genotypes collected from East and Southern Africa. PC2 accounted for 2.48% of the variation and was associated with five genotypes collected from East, West and Southern Africa. Transgressive segregation for a number of traits was observed in the two F2 bi-parental populations, as some individual lines in the segregating populations showed trait values greater or less than their parents. The variability between twelve genotypes and the two F2 bi-parental segregating populations and the negative relationship between plant architectural traits and yield related traits provide resources for development of structured populations and breeding lines for bambara groundnut breeding programme.