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.

Angular leaf spot (ALS) caused by Pseudocercospora griseola (Sacc.) is one of the serious fungal diseases affecting dry bean in Africa, including South Africa. Host plant resistance is the best management strategy, of which its effectiveness requires knowledge of the genetics underlying the resistance in guiding breeding efforts. In this study, the inheritance of ALS resistance was studied through the generation mean analysis biometrical procedure. Six generations consisting of the two parents Ukulinga and Gadra, and its cross derived filial progenies (F1), second-generation (F2), and backcrosses of F1 to Ukulinga (BCP1) and Gadra (BCP2) were planted in a net-house and later inoculated using a mixture of P. griseola isolates. Leaf lesions (% disease severity) were rated using a CIAT 1-9 scale and analysed using SAS macros in Proc GLM of SAS version 9.3. Results of ANOVA for a full model displayed significant additive effects (P<0.05) and highly significant (P<0.001) additive x dominance effects. Segregation analysis indicated 9:7 ratio, implying the involvement of complementary gene effects. The number of genes was estimated to be 1.79; however, due to epistasis two or more genes possibly govern the resistance in this cross. Broad and narrow sense heritabilities were 0.40 and 0.33, respectively. Therefore, the estimated narrow-sense heritability, additive gene effects, and epistatic interaction imply that it is prudent to delay selections until later stages, in which homozygosity could be achieved and additive effects fixed.

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