StatusThe thesis was presented on the 30 July, 2008
Approved by NCAA on the 23 October, 2008
Abstract– 0.31 Mb / in romanian
– 0.53 Mb / in russian
ThesisCZU 74/577:550.47(478.9) 1.10 Mb / in russian
The given thesis contains the results of investigations of the peculiarities of the migration and accumulation of selenium on the territory of eastern and south-eastern regions of the Republic of Moldova.
It has been found out that geochemical conditions of the regions under study are suitable for the migration of selenium in various ecosystem components and its accumulation in plants. The high concentration of selenium in both surface and ground waters has been confirmed.
The level of the selenium content in the soils of the regions under study, in general, in conformity with the conditionally determined optimal area. Hence, the content of selenium in the soils of forest-steppe zones is higher than in those of steppe zones. It is of interest that in the latter zones some areas of marginal insufficiency of the microelement or even the deficiency of it has been spotted. The given research has revealed not only the differences in the concentration of selenium in various soil types, depending on certain relief elements in the valley of the Dniester, but also certain regularities in the distribution of selenium on the vertical soil profile.
In the surface part of plants the decrease in the bioaccumulation of selenium has been noticed from alfalfa to sunflower and then to barley, wheat and maize. A positive correlation between the content of copper in soil and the content of selenium in maize has been determined against low copper concentration. In the plants with a low content of sylph-bearing amino acids the increase of cysteine is followed by the decrease of selenium, and, vice versa, with the increase of methyonine the accumulation of selenium in plants has the tendency to going up.
The data of the author demonstrate the high level of selenium content in the blood serum of the people of the Republic of Moldova, living in the valley of the Dniester. Also the status of selenium has been found to be significantly higher in rural than in urban zones. The author succeeded in getting the equation of regression allowing one to calculate the average level of selenium content in the human body for a certain zone according to biochemical parameters for that region.