[en] Radiotoxins (RT) isolated from γ-irradiated (10 krad) potato tubers and administered per os to male mice induce chromosomal aberrations (bridges and fragments) in the bone marrow cells (upto 19.63%). The percentage of cells with similar chromosomal aberrations in the groups of intact animals, that have received extracts from non-irradiated potato and a physiological solution is 5.01% and 3.19%, respectively. In addition to chromosomal aberrations, certain cytogenetic disorders in the bone marrow cells are observed in the experimental group of mice, namely, attached chromosomes and retarded chromosomes in the anaphase. The genetic effects observed confirm the mutagenic activity of RT formed in the irradiated plant tissue