Specificity of phototrophic terrestrial microbial complexes under wheat crops

The article presents the results of determining the species and quantitative composition of algae and cyanobacteria in terrestrial growths under wheat crops. The wheat seeds were inoculated with various microorganisms in mono-, binary and triple combinations before sowing. Algocyanoflora of the “blooming” soil was represented by 24 species: Cyanobacteria – 7; Chlorophyta + Streptophyta – 12; Bacillariophyta – 5. The inoculants were representatives of prokaryotic and eukaryotic microorganisms – antagonists of Fischerella muscicola, Trichoderma sp. and the phytopathogen Fusarium culmorum. In one of the experimental variants, pre-sowing treatment with the fungicide “Maksim”® was used. It has been shown that during the formation of soil “blooming” the dominant microbiomes are green algae (Chlorococcum infusionum, Klebsormidium flaccidum) and cyanobacteria (species of the genera Leptolyngbya, Phormidium). When determining the number of phototrophic populations, it was found that their density ranges from 1.8 to 8.1 million cells/cm2. At the same time, the maximum development of phototrophs was found in the control variant, and the minimum number was found in the variant with a chemical disinfectant. In variants with microbial inoculation, the peak development of microphototrophs is typical for treatment with a triple mixture and a binary mixture of Fischerella + Trichoderma. Determination of the structure of microbial populations showed that the strongest dominance of cyanobacteria (80,2%) was detected on an artificial infectious background caused by pre-sowing inoculation of wheat seeds with the phytopathogen F. culmorum. A relatively high content of cyanobacteria (up to 60%) is observed in 4 experimental variants (Fischerella, Fischerella + Trichoderma, Trichoderma + Fusarium, Fischerella +Fusarium) and in the remaining 4 variants there is some dominance of microscopic algae ranging from 52 to 58%. Therefore, according to the results obtained, microbial inoculation does not lead to radical changes in the state of terrestrial phototrophic microbial communities, while chemical fungicide significantly suppresses the development of algae and cyanobacteria.