Radiosensitivity Study for Identifying the Lethal Dose in MR219 (Oryza sativa L. spp. Indica cv. MR219)

The purpose of the research was determine the effects of gamma ray on seed germination, seedling height and root length of Rice (Oryza sativa L. spp. Indica cv. MR219) to identify the Lethal Dosage of the radiation. Paddy seeds of MR219 were exposed to different doses of gamma radiations viz 50,100,150,200,250,300,350,400,450,500,600,700,800,900 and 1000 Gy using 60Co as the radiation source. The effect of radiation was determined by measuring the Seed germination, seedling height, root length and emergence under the conditions of the M1 generation. The research results showed that the differences among radiation treatments significantly affect (p < 0.01) seedling height and root length. In part of seed germination percentage, insignificant differences were observed. Also the LD25 and LD50 values observed based on the growth reduction of seedlings after treatments occurred during 250 and 450GY of exposure for the variety Oryza sativa L. spp. Indica cv. MR219.