The effect of hypoxia on recovery of sublethal radiation damage in Vicia seedlings

Seedlings of Vicia faba were used as a test system to investigate the recovery of sub-lethal radiation damage. Groups of seedlings were exposed to single and fractionated doses under four treatment regimes; air present during the irradiations and during the interval between dose fractions; air present during the irradiations but hypoxic conditions between the doses; hypoxia during the doses but air available between doses; hypoxia maintained both during and between the irradiations. It was found that some degree of recovery of sub-lethal damage took place under all conditions, but the amount of recovery was substantially reduced if a state of hypoxia was maintained between the dose fractions. The state ofoxygenation during the X-ray exposures was relatively unimportant.