Effect of moisture stabilization period on radiosensitivity of barley seeds

Abstract

An experiment was designed to study the nature of the increase in radiosensitivity at high moisture levels. Seed lots were stabilized for different periods (2-16 weeks) so as to attain uniformly high (25%) water content and were then irradiated with ⁶⁰Co γ-rays (28·56 and 42·84 kR for growth studies and 28·0 and 40 kR for cytological experiments). Unirradiated controls showed little difference in growth as a result of differences in equilibration periods. On the other hand, irradiated seeds showed an increase in radiosensitivity with increasing equilibration period. The role of any alteration in the respiration and/or chromosomal duplication was then assessed. The change in respiration rate (presumably affecting the intracellular oxygen tension) was apparently better correlated with the increase in radiosensitivity.