Waterlogging responses of colchicine- and silver nanoparticle-derived Bambara groundnut mutant lines

Abstract

Waterlogging is a major abiotic stress limiting Bambara groundnut (Vigna subterranea) productivity in poorly drained environments, yet the performance of induced mutant lines under excess moisture remains poorly understood. This study evaluated the physiobiochemical and yield responses of colchicine- and green silver nanoparticle-derived Bambara groundnut mutant lines under waterlogging stress imposed at flowering. Selected mutant lines from three genotypic backgrounds, MOK01, MOK02 and PTG01, together with their corresponding parental controls, were exposed to 10 days of waterlogging and assessed for survival, antioxidant activity, lipid peroxidation, proline accumulation, chlorophyll retention, morphophysiological traits and yield components. Significant variation was observed among the lines. PTG01 0.025% colchicine showed 100% survival with high catalase activity, moderate malondialdehyde accumulation, improved chlorophyll retention, high pod number, heavy seeds and high seed yield. MOK01 0.05% colchicine also showed strong yield performance and high shelling percentage. In contrast, silver nanoparticle-derived and combined lines showed inconsistent responses that did not consistently improve survival or yield. Pod number showed the strongest association with seed yield, while most physiological traits showed weak to moderate relationships. The findings identify PTG01 0.025% colchicine as a promising line for further multilocation evaluation.