[Cytogenetic effects in native populations of Crepis tectorum exposed to chronic irradiation in the vicinity of the Chernobyl Nuclear Power Station. Induction of chromosome aberrations during the first 2 years following the accident].

During the first year after the accident the maximum frequency of Crepis tectorum cells with chromosome aberrations amounted to 10.2 to 15.3% at a dose-rate of 5-10 mR/h (gamma-radiation), cells with multiple aberrations being rather frequent. During the second year, in the areas where a dose-rate was 20 to 0.02-0.03 mR/h, the number of cells with chromosome aberrations amounted to 1.4-2.2% at the highest dose-rates. Besides, plants were found with the altered karyotype which was indicative of active microevolutionary processes in chronically exposed populations.