Electronic Journal of Plant Breeding

The biological effect of new source of physical mutagen viz., electron beam over gamma rays were studied with different dosages in the M1 generation of rice during 2017–18. The seeds of rice variety Anna (R) 4 rice were treated with 100 to 400 Gy of electron beam and gamma rays. At higher dosage level of 400 Gy both in gamma rays and electron beam, the germination percentage was reduced to 28 and 24 per cent respectively. The LD₅₀ value was fixed as 273.27 Gy for electron beam, which is much lower dose than gamma rays (376.57Gy). During germination, root length was more affected than shoot length in both radiations. The electron beam irradiation affected maximum reduction in pollen fertility (61.87%) and in spikelet fertility (72.75%) at 400 Gy, whereas at same dose lesser reduction was observed in gamma rays. The relationship between pollen and spikelet fertility showed positive significant. The above information obtained from this study is more useful to understand the effect of electron beam on rice over gamma rays and also help to decide the dose for future mutation breeding programme in rice.