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.