Bambara groundnut is an important food legume crop, cultivated mainly in sub-Saharan Africa. Crop plants that are indigenous to the local people are also a valuable biological resource for screening and evaluating the toxicity of the chemical substances with mutagenic effects. In this study, different caffeine concentrations were used to investigate their effect on seed germination of Bambara groundnut. The seeds were pre-soaked in distilled water for 12 hours and then exposed to the different concentrations of the caffeine dose of 0.0, 0.05, 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 1.75 and 2.0%, prepared in a phosphate buffer of pH-7. Three replications of the treatments were made and sown each seed of the treatment concentrations in a pot to rise the M1 generation using Complete Randomized Block Design (CRBD). Seed germination was scored for seven days and the germinated seedlings were further observed for 9 weeks. The radicle length, shoot height, and stem girth was measured at the 13 weeks after germination. From the results, it was evident that increased concentration of caffeine reduced the germination percentage of the seeds. In the caffeine concentrations of 1.75-2.0% recorded no germination compare with more than 90% germination at the end of the 7 days of 0.05-0.25% caffeine concentrations. There was a reduction in radicle length as the caffeine concentration increased at 7 weeks after planting. 0.5% caffeine concentration recorded the highest shoot length of 3.32cm among the caffeine concentrations with no significant differences detected in the stem girth studied.
Key words: Caffeine, Bambara nuts, germination