IMPROVEMENT OF FOOD BEANS (PHASEOLUS VULGARIS L.) THROUGH MUTATION BREEDING

Advanced generation lines derived for radiation-treated bean cultivar 'Canadian Wonder' were evaluated for their performance and response to Rhizobium inoculation in replicated trials for two seasons in 1984. In the early generations (M₁ to M₃), the variants were selected for resistance to common bean diseases in Kenya, anthracnose, angular leafspot, and rust. The M₅ and M₆ lines showed increased grain yield (11%), 100-seed weight and matured earlier compared to non-irradiated controls. Inoculation increased grain and seed weight but delayed maturity. The mutant lines generally exceeded control cultivars in grain yield, although the differences were not significant in some instances.