Saline stress negatively affects early onyogenesis of plants. The use of biologics is promising to overcome the negative effects of stress. The purpose of the work was to detect the reaction of winter wheat in the conditions of sulfate, chloride and carbonate salinity and the effect of the Regoplant drug on the crop at different stress intensity.

The research was carried out using winter wheat seed of the Zira variety. Seeds were treated with the biopreparate in the manufacturer's recommended dosage. During the experiment, germination energy and laboratory seeds similarity, length of seedlings and root system, dry mass of seedlings and roots of winter wheat were determined.

In this study, it is observed that sulfate salinity exhibits the least stressful reaction to the plant organism. Germination energy gradually decreased from 90,7 % to 47,0 % and the laboratory similarity from 92,4 % to 48,9 % with an increase in the concentration of saline solution.

With sodium chloride salinization, the negative effect of salt loading on the energy of winter wheat germination is more pronounced, and in comparison with plants without stress, this indicator decreased by 1.16-1.64 times, and the laboratory similarity – by 1.15–1.64 times.

Sodium hydrogencarbonate caused the greatest stress for seedlings and the germination energy decreased from 68.40 % to 21.40 %, the laboratory similarity – from 72.0 % to 17.25 %.

It has been shown that the Stympo positively affects the early stages of winter wheat development. The preparate caused an increase in the laboratory similarity by 1.02-1.83 times and the germination energy in 1,03-1,53 times on the salinization of soil background, depending on the type of salinity. It increased growth of seedlings by an average of 11.6–51.2 % and roots by 7.4–51.5 %, and the accumulation of dry matter compared with plants sprouted in an environment of the appropriate salinity type.

With an increase in the inhibitory effect of hydrocarbon salinization, the positive effect of the Stympo bioregulator becomes more visible. At the same time, there is a significant difference in comparison with plants sprouted on a carbonate background in the length of seedlings and roots at all salt concentrations.

In all variants with different types of salinization with increasing concentration of the solution, we observe a gradual decrease in the process of accumulation of dry mass of seedlings and root system. Accordingly, the smallest inhibitory effect was observed in the sulfate type of salinity, and the largest in the case of carbonate.

The bioregulator containing Na₂SO₄ caused a reliable increase in the seedlings dry weight – by 1.35-1.52 times and dry mass of the roots increase by 1.19-1.23 times as compared to the saline control. Accordingly, these figures increased under chloride salinization in seedlings by 27.4-38.6 % and in the roots of by 28.9-79.1 %. Under the influence of sodium hydrogen carbonate on the plant, Stympo preparate showed a positive effect on the accumulation of dry matter, and thus the dry mass of seedlings increased by 28.4–47.4 % and the roots by 18.6-41.7 % compared with the NaHCO₃ variant.

Thus, a significant difference was observed in the increaseof the l seedlings ength – by 8.9 %, the length of the root system – by 5.9 %, and the dry weight of seedlings – 14.8 %, under the use of Stympo biopreparate as compared with the control variant.

It is promising to carry out further research into the effects of the Stympo drug on the adaptation of plants at different stress levels and its effect on winter wheat productivity.

Key words: biopreparate, Stympo, winter wheat, salinity, stress, stimulation.