INFLUENCE OF AZOTOBACTER VINELANDII IMV B-7076 ON THE GROWTH OF WHEAT AND THE SYNTHESIS OF EXOMETABOLITES IN HYDROPONIC CONDITIONS

Objective. Determine the influence of Azotobacter vinelandii ІМV В-7076 on the in vitro synthesis of exometabolites by wheat plants. Methods. Experiments were carried out with the winter wheat of Shestopalivka variety, which seeds first underwent surface sterilized and then grown for 14 days under the conditions of hydroponics with A. vinelandii ІМV В-7076. Bacteria were grown in 700 mL E-flasks contained 100 mL of Ashby medium and incubated on the orbital shakers at 220 rpm at 28 °С during two days. The wheat plants were grown in 1.5 L cylindrical glass vessels of 115 mm in diameter and 160 mm height. Stainless steel meshes were placed in the vessels at a distance of 5 mm from the bottom. The vessels were sterilized, after which 75 mL of sterile Farreus medium was added. After seed germination, five sprouts were placed on stainless steel meshes in glasses. Azotobacter suspensions were added to the medium in three different dilutions (105, 106 and 107 cells/mL, respectively). The effect of bacteria on plant morphometric parameters, chlorophyll and carotenoid content in plant leaves, and the accumulation of carbohydrates, proteins and phenolic compounds in the medium with root exudates were determined. Results. It was found that growing wheat on a medium with A. vinelandii IMV B-7076 had a positive effect on plant growth, the content of photosynthetic pigments in leaves and the accumulation of proteins, phenols and carbohydrates in root exudates. The stimulating effect of Azotobacter increased with an increase in the content of cells in the medium. When growing plants on a medium with 107 cells/mL, the length of sprouts increased by 26.4 % compared to the control (without Azotobacter), and the weight of plants increased by 63.6 %. When growing wheat plants under such conditions, the content of proteins and carbohydrates in the medium with plant root exudates increased more than twice compared to the control, and phenolic compounds — by 79.8 %. Conclusion. A. vinelandii ІМV В-7076 has the positive effect on the growth and development of the wheat plants and synthesis of exometabolites.