Abstract
In this study, we investigated the cytogenetic effects of exposure to chronic radioactive contamination on the populations of Rosa spinosissima L. and Leymus angustus (Trin.) Pilg. growing in fields affected by radioactive water streams from the 'Degelen' test location of the Semipalatinsk test site. The results revealed that the radiation dose absorbed by these plants varied from 108 to 1,150 µGy/day, depending on the sampling points of the plants. The main exposure dose received by the plants was from 90Sr and 137Cs. In both plant species, chromosomal aberrations were the main contributors to the range of cytogenetic effects (double bridges and double fragments). The proportions of chromosomal aberrations were the highest among all cytogenetic effects at 42 and 54% in R. spinosissima and L. angustus, respectively. A linear relationship was established between the increase in the frequency of aberrant cells and the increase in the rate of radiation dose absorption in R. spinosissima for the entire range of the absorbed doses in question up to 1,129 µGy/day and in L. angustus for the range of absorbed doses from 152-583 µGy/day.