Recent Levels of Radionuclide Contamination in the Eastern Ural Radioactive Trace and Biological Effects in Local Populations of <Emphasis Type="Italic">Plantago major</Emphasis> L.

The results of the study have shown that the stocks of ⁹⁰Sr and ¹³⁷Cs in the frontal part of the EURT are 6700–15000 and 200–400 kBq/m², respectively. The coefficients of their accumulation in different herbaceous plant species in this impact zone are lower than in other areas. The accumulative capability of plants has probably decreased in the course of selection as an adaptation to the effect of radiation. The viability and growth parameters of Plantago major L. seeds from the EURT zone are similar to those of seeds from the background sample. Cenopopulations chronically exposed to radiation are characterized by a higher mutation rate in the progeny and an unstable response to additional acute irradiation in most characters studied. A high level of inbreeding is observed in all P. major cenopopulations of plantain. The cenopopulation of the impact zone is characterized by a lower variation of allozyme loci, which may be a result of stringent selection for individuals better adapted to the complex of conditions existing in its habitat.