Effects of Sulphur Dioxide and Fluoride on Ascospore Germination of Several Lichens

Abstract

AbstractThe effects of fluoride and sulphur dioxide on the germination of ascospores of Lecanora conizaeoides, Xanthoria parietina, Physconia distorta and Peltigera canina were studied under controlled conditions. The two pollutants (H2SO3 and NaF) were dissolved in the culture medium. An improved culture technique permitted a high percentage germination (90° 0) of P. canina spores. Peltigera canina spores had the highest sensitivity to SO2 (no germination at 500 UM H2SO3). Lecanora conizaeoides spores were almost insensitive to each of the two studied pollutants (30°0 spore germination at 1000 UM H2SO3 or NaF). However, simultaneous exposure to 1000 UM H2SO3 and 1000 UM NaF resulted in no germination, indicating a synergistic effect of these products.