Genetic divergence in gamma-rays induced mutants of rice bean (Vigna umbellata).

摘要

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 among themselves. Thus, Gamma-rays treatment was an effective tool in creation of micromutational variation in the polygenic traits. The high D2 values and character complementation for productivity traits in mutants indicated that crosses among mutant RBL1-8 x RBL1-8, RBL1-8 x RBL1-10, RBL6-2 x RBL6-5, RBL6-2 x RBL6-10, PRR2-10 x PRR2-12, PRR2-3 x PRR2-9, PRR9302-5 x PRR9302-11 and PRR9302-11 x PRR9302-12 would give more transgressive segregates for yield and other desirable traits.