Moskalyk G. . Activity of the Key Enzymes of Nitrogen Metabolism of Lettuce by Acting of Nitrogen and Ammonium Nitrate and Synthetic cytokinins.

The peculiarities of the regulation of activities key enzymes of the nitrogen metabolism - nitrate reductase, glutamine synthctase, glutamate dehydrogenase by nitrogen and ammonium nitrate separately and together with synthetic cytokinins are shown in the thesis work. It has been noted that ammonium nitrogen assimilation in the organs of lettuce took place both in glutamine synthetase and glutamate dehydrogenase way. The formation of the reserve pool of nitrates irrespective of the form and nitrogen concentration in the medium has been determined. A comparative investigation of the influence of the cytokinins monomer form - BAP and its polymeric analogue - polystimuline К on the activity of key enzymes has been done. The influence of monomer analogue of cytocinins on the shown parameters in the phase of two real leaves and polymeric in the phase of technical ripeness arc shown there.