[The cytogenetic effects in natural populations of Crepis tectorum exposed to chronic irradiation in the region of the Chernobyl Atomic Electric Power Station. An analysis of the frequency of chromosome aberrations and karyotype changes in the 3rd and 4th years after the accident].

In three natural Crepis tectorum populations from 30-km zone of the Chernobyl NPP cytogenetic analysis of plant progenies was carried out. Germination capacity was not correlated with the dose rate of chronic irradiation. There was a correlation between frequency of cells with chromosome aberrations and frequency of seedlings with non-identical altered karyotype among which pericentric inversions and reciprocal translocations dominated. 9-chromosome altered karyotypes were found. Homozygous plants with altered karyotypes were not observed. Several heterozygous plants segregated homozygous seedlings with altered karyotype were found. In comparison with the second year after the accident in the third and fourth years there was stronger deviation from linear dependence between the cytogenetic effect and the dose rate of irradiation.