Bambara groundnut is a highly nutritious food legume. However, the low genetic variability in Bambara,groundnut constitutes a serious barrier for its improvement. The mutagenesis is one of the techniques able to create genetic variability of crops species for breeding. This study aims at evaluating the genetic variability induced by gamma irradiations within the second generation of mutants (M2). Thus, 40 families of M2 mutants resulting from the mutagenesis of three Bambara groundnut varieties (KVS115, KVS234 and KVS259) were characterized using a Fisher block design with three replicates. Twenty-two (22) characters related to phenology, morphology and yield were used for the characterization. The results showed highly significant differences between M2 mutant families for all the evaluated traits. Significant variability was recorded for the traits number of pods per plant, weight of pods, seeds weight, yield and number of leaves for which high coefficients of variation were observed (CV > 44%). The number of pods per plant, grain yield, seed weight and pod weight per plant, terminal leaflet length and width, and number of leaves presented high phenotypic and genotypic coefficients of variation (˃20%). High heritability (H2 > 60%) associated with high genetic advance value (GA > 72%) were registered for number of pods per plant, pods weight per plant, seed weight per plant and grain yield. Three classes were revealed from the Hierarchical ascending classification of the studied mutants. The first class comprised of fairly late maturing mutants (> 88 days), the second of and high yielding mutants (102-258 g/m2), while the third class comprised mutants with important aerial biomass. This significant variability could be used in Bambara groundnut improvement programs for creating highly performing varieties adapted to various biotic and abiotic constraints.

Bambara groundnut, Gamma irradiation, Genetic variability, Burkina Faso