Influence of Dose, Environmental Conditions and Nuclear Volume on Survival Times in Several Gamma-irradiated Plant Species

Summary

A relationship between environmental conditions (light and temperature) and mean survival time (MST) after gamma-irradiation has been shown for plant species from six genera (Arabidopsis Capsella Chrysanthemum Raphanus Tradescantia, and Tropaeolum). A five-fold difference among species in MST after irradiation was found to be directly related to nuclear volume (NV). The regression MST(Y) versus NV(X) has the form log Y = −0·515 + 0·597 log X, and a correlation coefficient of 0·92. An increase of 8°C in temperature after irradiation decreased the MST and reduced survival (by over 50 per cent for Arabidopsis thaliana). Decreased post-irradiation temperature increased the MST and the percentage survival of Arabidopsis and Capsella bursa-pastoris. A correlation between decreasing survival time and increasing dose also was demonstrated for these two species. The importance of allowing sufficient observation time and controlling environmental conditions after irradiation to determine accurate levels of survival and, thereby, the radiosensitivity of plant and animal species is discussed.