Seeds of four rice bean varieties viz., RBL-1, RBL-6, PRR-2 and PRR-9302 were treated with 40
kr dose of Gamma-rays. Twelve high yielding plants from M2 population of each variety were selected for M3 generation study, along with the respective parents. Observations on days to flowering, maturity, plant height, branches/plant, clusters/plant, pods/plant, seeds/pod, 100-seed weight and yield were recorded. The genetic divergence (D2) estimates among the M3 lines and the parent in all four varieties showed wide variation. Using Tocher’s method the M3 lines of RBL-1, RBL-6, PRR-2 and PRR-9302 were grouped into 5, 6, 4 and 5 genetic clusters, respectively. 8, 8, 7 and 5 M3 lines of RBL- 1, RBL-6, PRR-2 and PRR-9302, respectively, grouped into diverse genetic clusters away from the parent indicating large genetic diversity of these lines compared to the parents and also amongthemselves. Thus, Gamma-rays treatment was an effective tool in creation of micromutational variationin the polygenic traits. The high D2 values and charactercomplementation for productivity traits in mutants indicated that crosses among mutant RBL1-8 × RBL1-8, RBL1-8 × RBL1-10, RBL6-2 × RBL6-5, RBL6-2 × RBL6-10, PRR2-10 × PRR2-12, PRR2-3 × PRR2-9, PRR9302-5 × PRR9302-11 and PRR 9302-11 × PRR 9302-12 would give more transgressive segregants for yield and other desirable traits.
