Peculiarities of 137Cs translocation in higher plants under environmental and laboratory conditions

Accumulation of technogenic 137Cs in higher plant roots and above-ground part and comparison of 137Cs and 40K transfer from roots to the above-ground part of plant as well as distribution within above-ground part of plant under environmental conditions were investigated. Parallely, the results of the investigations of 137Cs accumulation in the roots and shoots of test-organism Lepidium sativum L. in the model hydroponic system aqueous solution-solid phase-plant were analyzed. Peculiarities of transfer of this radionuclide from roots to shoots during the entire plant growing period under experimental conditions were determined. 137Cs activity in the tested plants of meadow ecotop was on an average 6-fold lower than in the plants of swamp and 10-fold lower than in the plants of forest ecotop. Differences in 137Cs and 40K transfer from roots to the above-ground part of plant and their distribution in plants indicate particular biological metabolism of these radionuclides in plants. Increased levels of 137Cs in soil practically did not affect the 40K transfer from roots to the above-ground part of plants. The results of investigations under natural and laboratory conditions show that increasing contamination of growth medium with 137Cs caused higher accumulation of this radionuclide in roots but its transfer from roots to the above-ground part of plant decreased or changed insignificantly. 137Cs transfer from roots to above-ground part under natural (Artemisia vulgaris) and laboratory (Lepidium sativum) conditions was rather similar. (authors)