SYMBIOTIC PRODUCTIVITY OF PHYTO-BACTERIAL SYSTEMS UNDER THE ACTION OF N-ACETYL-D-GLUCOSAMINE ON DIAZOTROPHIC MICROORGANISMS

The purpose of the work was to evaluate the symbiotic productivity of soybean‒rhizobium and wheat‒azotobacter phyto-bacterial systems under the action of N-acetyl-D-glucosamine (0.01 M; 0.1 M) in vitro on the cultures of nitrogen-fixing microorganisms Bradyrhizobium japonicum 634b and Azotobacter chroococcum Т79. We have used such indicators as plants biological and seed productivity, rhizobia nodulation ability and nitrogenase activity of soybean symbioses as well as wheat rhizosphere microbiota. It was shown that the biological activity of N-acetyl-D-glucosamine during incubation with soybean nodule bacteria had a higher level of realization of the rhizobia nodulation ability: plants were more actively infected (by 12%), a greater number of nodules were formed (1.2‒2.3 times) with their greater total mass per plant (1.4‒2.1 times) and the mass of each root nodule (1.2 times), as well as the nitrogen-fixing activity of the symbiosis (1.7 times) and the functional capacity of each morpho-structural symbiotic unit (1.4 times). It provided higher (by 14‒29%) seed productivity of this system as compared with the symbiosis formed by the rhizobia monoculture. Activation of basic physiological processes in wheat such as nitrogen fixation (the activity of the rhizosphere microbiota was increased by 1.1‒1.4 times) and photosynthesis (the content of chlorophylls in leaves was increased by 1.1‒1.2 times) with N-acetyl-D-glucosamine-modified azotobacter provided a higher level of realization of the productive potential of this system in comparison with both non-infected plants (by 15%) and the variant of seed inoculation with bacteria only (by 7%). While inoculants bacteria + glucosamine had positive effect on seed productivity of the symbiotic and associative systems, it was shown no significant change in the biological productivity of soybean and wheat plants. So, the use of N-acetyl-D-glucosamine as an additional agent of carbohydrate nature in inoculants with soybean nodule bacteria and soil diazotrophs of Azotobacter genus led to a more complete realization of the symbiotic and productive potential of phyto-bacterial symbiosis and association when compared to using a diazotrophs only. Our results indicated the possibility of practical use of acetylated glucose-containing aminosaccharide in the creation of complex inoculants based on nitrogen-fixing bacteria.