Induction of mutation in tomato (Solanum lycopersicum L.) by gamma irradiation and EMS

Abstract

Induction of mutation by gamma rays, ethyl methane sulfonate (EMS) and their combined treatments was studied in three widely divergent genotypes of tomato, EC620176, EC620177 and Patharkutchi. A steady reduction in germination percentage, seedling height and pollen fertility occurred in M1 generation with the increasing doses / concentrations of mutagens. Combination of gamma radiation and EMS caused more damage followed by EMS treatment and gamma radiation alone in M1 generation. The LD50 dose for EC620176, EC620177 and Patharkutchi corresponded to 67.3 Gy, 290.9 Gy and 303.8 Gy gamma radiation, and 0.10%, 0.17 % and 0.38 % EMS treatment, respectively. Highest mutation frequency was resulted by gamma radiation followed by the combined mutagens and EMS treatment. Genotype and mutagen, both, influenced the production of mutants. Mutagenic efficiency of lower doses/concentrations was more compared to higher doses in producing desirable mutants. Mutagenic effectiveness of gamma radiation was the highest followed by sole EMS and combined mutagens. Gamma irradiation (50-150 Gy) was most efficient followed by 0.05-0.10 % EMS and their combination treatment in inducing wide array of macromutation in tomato. Five putative mutants with exserted stigma flower, dark green fruit, dwarf plant having pyriform fruit from Patharkutchi, multiparous cyme from EC620177 and chlorophyll deficient mutant from EC620176 that could be isolated in M2 generation hold promise for their utilization in tomato breeding programme.