Modification of radiation damage with storage in seeds irradiated with thermal neutrons

Irradiation of seeds with thermal neutrons induces radioactivity in seeds. A study was undertaken to find out how the storage of the radioactive seeds, and consequent decay of activity, modify the radiation damage. Immediate hydration after thermal neutron irradiation of rice seeds showed higher mutation frequency than that obtained after storage of the seeds for 10 days. The spectrum of chlorophyll mutations was also different. Chromosome aberrations were scored in barley seeds in which immediate hydration increased the frequency of chromosome fragments. The study of γ-ray spectra and β-activity in irradiated rice and barley seeds showed detectable activation of Mg, P, K and Cu. Transmutation of elements and internal radioactivity are considered likely to contribute to the radiation damage. Even though the activity by itself is too small to cause direct damage, transmutation and internal activity may be able to modify the initial radiation damage in diverse ways. Restitution or repair of the lesions may have been affected leading to the enhanced effects noted in the present study