Effects of gamma radiation on lichens—i. acute gamma radiation on lichen algae and fungi

Abstract

Gannutz T.P. Effects of gamma radiation on lichens—I. Acute gamma radiation on lichen algae and fungi. Radiation Botany 12, 331–338. 1972.-The effects of acute gamma irradiation on isolated cultures of lichen algae and fungi have been determined quantatively. Lichen algae were more radiosensitive than the lichen fungi, even among components from the same species of lichen. This is in direct correlation to the effects of natural environmental stress. Although the lichen fungi have similar radiosensitivities to similar free-living fungi, the irradiated lichen fungi were entirely in the vegetative state (i.e. not in stages of reproduction or sporulation). Consequently, it is apparent that the lichen fungi are less radiosensitive than similar free-living fungi. Radiosensitivities of lichen algae and free-living algae were similar. When comparisons are made with intact thalli growing in a chronically irradiated situation, it appears that the intact thallus is more radiosensitive than either the algal or fungal component in culture. It is postulated that this is due to the addition of another stress (i.e. radiation) on an already strained symbiotic relationship. Correlations were attempted between the various species of algae and fungi, their radiosensitivities, and water, lipid, and DNA contents.