[Does Radioecological Paradox Exist?].

In some cases radioresistant species of plants in radionuclide-contaminated areas have more strong radiation damages than radiosensitive ones. This effect was called "the radioecological paradox". It could be explained by different abilities to accumulate main dose forming radionuclides. It leads to formation of higher doses due to internal irradiation. In the case of the Chernobyl N PP accident it can be conditioned by species specific particularities in consumption of potassium and calcium, and cesium and strontium, correspondingly.

[Effect of soil microflora on 137Cs transition to plants].

The impact of certain types of microorganisms on 137Cs transfer from the substrate into the plant was analyzed in the experiment on artificial mediums. It was found that certain types of microorganisms could either reduce or increase the ratio of 137Cs transfer from the substrate to the plant. It is shown that this property is independent of the localization of the microorganism on the surface of the root, for all the analyzed bacteria belonging to the rhizospheric group. Azotobacter chroococcum UKM B-6003 stimulated the radionuclide transfer to plants up to 1.5 times, while the best bacteria for reducing its accumulation is Burkholderia sp IMER-B1 -53 - 1.3 times in comparison with the control. It was shown that the strain Bacillus megaterium UKM B-5724 from the collection of the Institute of Microbiology and Virology of NASU has a high ability to accumulate radionuclides.

[The role of trace elements in radiation protection of plants and animals on radionuclide contaminated territories of Poles'e].

The retrospective review and analysis of works on some physiologically active trace elements influence on the radionuclides transfer from soil to plants and with forage to animals are presented. Also reviewed is their radioresistance in the contaminated territories. It is shown that some elements--zinc, manganese, cobalt--being appled to the soil at seeding or spraying plants with aqueous solutions and also in complex compounds are capable of reducing significantly the 90Sr and 137Cs transit to agricultural plants, and with forage--into the animals bodies. We have also shown that trace elements reduce the effects of radiation injury. The mechanisms of the radioprotective action of trace elements are also discussed in the paper.

[Application of the ferrocin containing waste of wine-making for reduction of 137Cs tansit from forage to laboratory animal organisms and cow milk].

Addition to rat ration of ferrocin containing wastes of wine-making formed during the process of wine demetalization in the amount of 0.2 g per animal per day reduces the 137Cs content in organs and tissues in 1.5-7 times. Addition of the above-mentioned substance to the ration of milk cows in the amount of 10-16 g per day reduces the radionuclide content in milk 1.5-2 times in two weeks and more than 3 times in four weeks.

[Radiation injury of the plants in the zone of influence of the accident on Chernobyl Nuclear Power Station (NPS)].

Were considered the radiobiological effects in some species of agricultural and wild growing plants in 30-kilometer zone of alienation of Chernobyl nuclear power station and other radionuclide contaminated territories. The particular attention was given to the distance plant reactions: immunity decreasing, genetic consequences, changes in phytocenosis. Was discussed the question of possibility of plant adaptation to conditions of high radiation influence.

[Use of metal salts for radioprotection of plants during radioactive pollution of the territory]. / Protivoluchevaia zashchita rastenii s pomoshch'iu solei metallov v usloviiakh radioaktivnogo zagriazneniia territorii.

The applying salts of some metals to radionuclide contaminated soddy-podzolic soil in the zone of Chernobyl nuclear power station or the spraying of plants by its solutions are showing the radioprotective effect (salts of iron, zinc, cobalt and manganese) and decreasing the uptake of 90Sr and 137Cs through roots (salts of zinc, manganese, boron, lithium, cobalt and copper).

Cell radiosensitivity variation in synchronously-dividing root meristems of Pisum sativum L. and Zea mays L. during the mitotic cycle.

The cell divisions in pea and maize seedling root meristems were synchronized by treatment with 0.03 per cent hydroxyurea for 24 hours. At different times after block cessation (removing seedlings from hydroxyurea), i.e. according to certain phases and subphases of the mitotic cycle, the seedlings were treated with 60Co gamma-radiation at doses from 3 to 32 Gy. Evaluation of seedling radioresistance by the survival of the main root meristem on the tenth day after irradiation led to the following sequence of cell stages in order of increasing resistance. For the pea root meristem: G2, M, late G1, early S, late S, middle S and early G1. For the maize root meristem: late G2, M, G1, early S, early G2, late S and middle S.

Induction by gamma-radiation of DNA synthesis in radicle cells of germinating seeds of Pisum sativum l.

In radicle meristem cells of germinating seeds of the pea (Pisum sativum L) before the onset of replicative synthesis of DNA, irradiation with 2-3 krad of gamma-rays induced the incorporation of 3H-thymidine (3H-TdR). Maximum isotope incorporation was noted during the first 2 hours after irradiation. Higher doses of radiation suppressed 3H-TdR incorporation. It was not seen after gamma-irradiation of air-dried seeds, nor after fast-neutron irradiation. The replication inhibitors hydroxyurea and 5-aminouracil had no effect on the gamma-induced incorporation of 3H-TdR, Whereas caffeine and acriflavine inhibited it to some extent. It is suggested that the gamma-radiation-induced incorporation of 3H-TdR in meristem cells during the pre-replicative period may be connected with repair phenomena.