Mykhalkiv L. Nitrogen fixation activity and productivity of alfalfa under different water supply conditions and growth regulators influence

The thesis is devoted to the studying of physiological peculiarities of Medicago-Sinorhizobium meliloti symbiotic systems under influence of plant growth regulators both synthetic and natural origin and in different water conditions, as well as to the investigation of possibility of alfalfa crop increase under water deficit by means of plant growth regulators and rhizobial periplasmic glucan employment. It has been established, that the treatment of plant with PS-K, PS-A-6 and TMFP soften negative water deficit effect on nodulation, nitrogen fixation, nitratereductase functional activity, nitrogen accumulation in above-ground part of plants, CO2-gas-exchange processes and productivity of alfalfa. The influence of growth regulators depend on water supply level, cultivars and microsymbiont strain. It has been proved the possibility of rhizobial periplasmic glucan to stimulate nitrogen fixation and growth processes in alfalfa in water deficit conditions.