INDUCTION OF MICRONUCLEI IN PLANT-CELLS AFTER EXPOSURE TO ACCELERATEDION IRRADIATION

The root apex cells of Pisum sativum were irradiated in an U-240 isoch ronous cyclotron at the Institute for Nuclear Research of the Ukrainia n National Academy of Sciences, Kyiv. Several types of micronuclei, di ffering in structural peculiarities, were observed in the 84 h followi ng exposure to beams of accelerated H-1, He-4, and N-14 ions with line ar energy transfer (LET) of 0.95, 9.34, and 221 keV/mu m, respectively . The maximum micronucleus induction was observed after irradiation wi th helium ions. Results obtained show that the micronucleus assay is a responsive test for investigations of cytogenetic damage produced by high LET beams in dividing cell systems in vivo.