Genetic effects observed in tetrads of Tradescantia induced by radon

Inflorescences of Tradescantia clone 4430 were exposed to different concent rations of radon (Rn) gas (0.85, 12.10, 36.50 and 98.16 kBq/m(3)) from plan ts placed in an acrylic chamber that received radon from a container with p itchblende (containing uranium mineral). The exposure time was 24 h, afterw ards the plants were left for 6 h in water and constantly aerated. Positive control plants were irradiated with gamma rays (0.8 Gy) and negative contr ol plants received ambient air only (the background measurement had a mean of 0.38 kBq/m(3)). Micronuclei (MCN) in the tetrads induced by a particles emitted from Rn were tabulated and a linear concentration response was obta ined. The potency of radon to induce MCN from the slope of the regression l ine was 0.13 MCN/kBq/m(3) of alpha-radiation. Radon could reach the anthers by diffusion through the aerial spaces within the buds. (C) 1999 Elsevier Science B.V. All rights reserved.