No abstract

Thirty years after the accident, the alienation zone of Chornobyl NPP continues to be an open source of radionuclide spread which is carried with superficial and soil waters into river systems and moves beyond the area. The study of mutagenic activity of radionuclide contamination of the water reservoirs in the near zone of Chornobyl NNP will make it possible to predict genetic consequences of their effect in the years after the accident. The purpose of this research is to study frequency and spectrum of chromosome aberrations in root meristem cells of Triticum aestivum L. under the prolonged effect of radionuclide contamination of water and bottom deposits of the water reservoirs in the near alienation zone of Chornobyl NPP. Seeds of winter wheat varieties Al’batros odes’kyi and Zymoiarka were sprouted in the conditions of the effect of water radionuclide contamination of the Prypiat River, Brahinka River, a reservoir-cooler of ChNPP, Semyhodskyi backwater, drainage-way 3 of ChNPP, Lakes Hlyboke and Azbuchyn (total specific activity of 137Cs and 90Sr – 0.17–52.99 Bq/м3) and bottom deposits of the left and right banks of Prypiat canal, a reservoir-cooler of ChNPP, drainage-ways 1–3 of ChNPP (total specific activity of 137Cs and 90Sr – 16.0–45.0 Bq/kg). Frequency and spectrum of cytogenetic disorders were identified in the cells of root meristem sprouts with help of the ana-telophase method. Under the influence of radiation on water and bottom deposits of the water reservoirs in the alienation zone of ChNPP, a 1.6–4.2 times increase in the frequency of chromosome aberrations and mitosis disorders was found. The highest levels of cytogenetic activity were shown by water radionuclide contamination in a reservoir-cooler of ChNPP, Semyhodskyi backwater and bottom deposits of drainage-way 2. The correlation between frequency of chromosome aberrations and specific value of radionuclide activity of water reservoirs has not been recorded, which can prove the induction of cytogenetic disorders resulting from the radiation in the low-rate range. The spectrum of cytogenetic disorder types is mostly represented by acentric fragments, bridges and lagging chromosomes. The induction of the cells with lagging chromosomes, which exhibit the highest levels (0.24–0.38%), under the effect of radionuclide contamination of water in Hlyboke Lake, the Brahinka River, the Prypiat River, a reservoir-cooler of ChNPP and bottom deposits of drainage-way 3, allows one to assume the availability of aneugenic factors in the water reservoirs in the alienation zone of ChNPP. The water entities of the alienation zone of ChNPP, the level of radionuclide contamination of which is characterized by a high cytogenetic activity, induce cells with complex chromosome rearrangements of high frequency. Despite the decrease in chromosome aberration frequency effected by the water of the Prypiat River near Chornobyl city, the Brahinka River and bottom deposits of the right bank of Prypiat canal, the increased level of aneugenic cells and the induction of multiple chromosome rearrangements confirm the persistence of mutagenic activity in the abovementioned contaminated water entities.

Досліджено ефективність симбіотичних систем сої за обробки рослин сорту Алмаз фунгіцидом аканто плюс у вегетаційних і польових умовах. Встановлено, що у вегетаційних умовах у варіантах із застосуванням фунгіциду за нормально сформованого симбіотичного апарату функціональна активність симбіозу була нижчою, ніж у необроблених рослин. При цьому виявлено і зменшення маси насіння, що свідчить про інгібування цим препаратом продукційного процесу соєво-ризобіального симбіозу. Згідно з результатами польових досліджень, застосування аканто плюс сприяє повнішій реалізації продуктивного потенціалу соєво-ризобіального симбіозу і забезпечує збільшення маси насіння на 21 % порівняно з контролем. Зроблено припущення, що такі зміни відбуваються внаслідок дії досліджуваного фунгіциду на фітопатогени, що сприяє відновленню здатності симбіотичного апарату рослин до повноцінного функціонування.

Aim.To study frequency and spectrum of chromosome aberrations in the cells of Triticum aestivum L. root meristem under a prolonged effect of radionuclides from water reservoirs in the proximal alienation zone of the Chernobyl nuclear power plant NPP. Methods. The seeds of two soft winter wheat varieties were treated with samples from water reservoirs in the alienation zone of the Chernobyl NPP. Ana-telophase analysis of chromosome aberrations in crushed cytological preparations of apical meristem of primary rootlets was carried out. Results. Radionuclides from water reservoirs in the proximal alienation zone of the Chornobyl NPP cause an increase in the occurrence of aberrant cells and mitoses by 1.6-4.2 times. The highest level of cytogenetic activity is typical for the radionuclides from the reservoir-cooler of the Chernobyl NPP, Semyhodskyi backwater, drainage N 3 of the NPP and Lake Hlyboke. The obseved aberrations are mostly represented by single and paired acentric fragments, bridges and lagging chromosomes. Conclusion. A prolonged exposure to ionizing radiation by radionuclides from the water reservoirs of the proximal alienation zone of the Chernobyl NPP produces leads to high cytogenetic activity. No correlation between the chromosome aberration level and the scope of specific radionuclides from water reservoirs was found; this may prove the induction of cytogenetic disorders under the radiation effect in the low-rate range. The increased level of aneuploid cells and those with multiple chromosome aberrations confirms genetic сonsequences for the organisms in water reservoirs even with a low specific activity of radionuclides. K e y w o r d s:Aberrations, cytogenetic disorders, radionuclide, low-rate radiation.

An important way of regulating the key units of metabolism in the plant organism under the action of stressors is the use of biologically active substances with regulating properties – plant growth regulators. They affect endogenous regulatory systems, altering key metabolic pathways and thus increasing the plant's sustainability and productive potential in adverse environmental conditions. The aim of the research was to establish the possibility of regulation of physiological processes in winter wheat varieties by exogenous treatment of plants with growth regulators of synthetic (salicylic acid) and natural (Emistim C and Biolan) origin to increase their resistance to the phytopathogen Erysiphe graminis DC f. sp. tritici Em. Marchal , the causative agent of powdery mildew. The intensity of the physiological processes in plants was evaluated by the dynamics of the activity of antioxidant enzymes – ascorbate peroxidase and catalase, the release of ethylene and the integrity of the cell membranes. The objects were selected varieties of soft winter wheat, which were grown in controlled growing conditions against the background of infection by powdery mildew. The treatment of plants was carried out using aqueous salicylic acid solutions in the concentration of 10–5 M (experimentally established by us), Emistim C and Biolan (manufacturer Agrobiotech) in the concentration specified by the manufacturer at the rate of 20 mL/ha, when the development of the disease reached 5% of the total natural background of the infection in the plants during the stages of heading-beginning of flowering. Infection of winter wheat with powdery mildew leads to disruption of cell membrane integrity, increased activity of catalase and ascorbate peroxidase in leaves of the susceptible winter wheat variety. The intensification of ethylene release by leaves of the resistant variety was observed, which was caused by the hypersensitive reaction of the hormone to the effect of stress. The use of plant treatment by growth regulators contributes to maintaining the integrity of membrane structures, adaptive changes in the activity of antioxidant enzymes and regulation of the synthesis of the stress hormone ethylene in both winter wheat varieties under stress. Such changes in the physiological processes induced by plant growth regulators are accompanied by the preservation of the grain productivity of winter wheat and the increase of their resistance to the development of the disease.