ABSTRACT
The influence of γ- rays on genetic variability is in direct correlation with the condition of irradiated material. Here we tried to increase the variability of Vicia faba L. var. major karyotype, after contamination with 131I (a kind of radioactive rain) in elongation phase in ten plant groups. The effects of irradiation were observed not only by controlling mitotic activity and calculating mitotic index in control and treated groups, but also by examination of every phase of mitotic and meiotic division. The values for normal and defect dividing cells are given in percentages. The most common types of aberrations were recorded during M1 generation.