Assessment of enzymative and microbiological activity of soil rhizosphere <i>Solanum tuberosum</i> L. under the influence of treatment of tubers with endophyte bacteria <i>Bacillus subtilis</i> in the conditions of the Cis-Ura

The effect of inoculation by endophytic bacteria Bacillus subtilis 26D and 10-4 on potato yield, its commercial quality, the prevalence of tuber diseases, the number of bacteria in different organs of the plant endosphere, the enzymatic activity of the soil of the rhizosphere of inoculated and non-inoculated (control) plants and the number of different trophic groups of microorganisms in dynamics were studied. Treatment with the B. subtilis 10-4 strain led to an increase in the total number of tubers from the bush by 35.4, their weight by 16.5%, and a decrease in the number of diseased tubers with signs of scab and dry rot. Treatment with strain B. subtilis 26D contributed to protection against dry rot while maintaining productivity at the control level without inoculation. The number of endophytic bacteria in different organs of the plant varied from 106 to 8×107 CFU/g of crude mass. A larger number of endophytes than in the control and inoculation variant with strain 26D was recorded in the treatment variant with strain 10-4 in the budding phase in the roots, and in the flowering phase in the stems and leaves. According to the ratio of polyphenol oxidase/peroxidase activity in the rhizosphere of the inoculated variants, the humus accumulation coefficient increased from 0.51 in the control without inoculation to 0.56 and 0.57 in the inoculation variants with endophytic bacteria. The intensity coefficient of hydrolysis of organic soil compounds (invertase/catalase activity ratio) it was 2 times less in the variant of inoculation with strain 10-4. The high and prolonged catalase activity in the rhizosphere of plants inoculated with strain 10-4 indicated a positive effect of endophytes not only on the preservation of soil fertility, but also on the effectiveness of biocontrol of phytopathogens. Differences in the microbiome of the rhizosphere of inoculated plants were associated with an increase in the number of micromycetes and a high coefficient of microbial mineralization in the treatment variant with strain 26D and the predominance of the number of oligonitrophils in the treatment with strain 10-4.