Mutagen Induced Responses in M₁ Generation of Black Turtle Bean (Phaseolus Vulgaris L.)

Present study was undertaken to evaluated the effect of gamma rays, ethyl methane sulphonate (EMS), and their combined treatments on biological characters in M₁ generation of black turtle bean (Phaseolus vulgaris L.). Genetically uniform seeds were exposed to different doses of gamma irradiation and EMS and grown under field conditions to assess mutagen-induced biological changes. Observations included chlorophyll injury, plant survival, pollen sterility, plant height, pods per plant, and seed yield per plant. The results obtained showed dose-dependent responses to mutagenic treatments. Chlorophyll injury increased with increasing mutagen dose, with the highest damage observed in combined treatments. Plant survival declined at higher doses, particularly under gamma irradiation and combination treatments. Pollen sterility also increased with mutagen intensity.,. Quantitative traits such as plant height, pods per plant, and seed yield showed gradual reduction with increasing doses.