[FORMATION AND FUNCTIONING OF SYMBIOTIC SYSTEMS AND RHIZOSPHERE MICROBIOCENISIS OF SOYBEAN UNDER VARIOUS FUNGICIDES APPLICATION].

The Relevance. At the recent years in soybean crops the quantity of plant pathogenic fungi has increased. The fungicides of systemic and contact action have been applicated intensively against of them. After introducing into the soil fungicides and/or their deg- radation products can to disrupt the activities of non-target objects - beneficial soil mi- croorganisms, inhibit nodulation process and the nitrogen-fixing activity of diazotrophs. The purpose of the work was to investigate the impact of combined application of fungi- cides with inoculation on the soybean symbiotic system and rhizosphere microorganisms. The Methods. The microbiological and statistical methods, gas chromatography method. The Results. Inoculation of seeds by the highly active Bradyrhizobiumjaponicum UCM B-6035, UCM B-6018 and UCM B-6023 strains the activity of nitrogen-fixing symbiotic systems increased by 1.4-3.4 times in comparison with the variant without of fungicides application and bacterization. Seed treatment by Vitavaks 200 FF fungicide caused a de- crease of'nitrogen-fixing activity of rhizobia industrial strains in symbiosis with soybean by 3-5 times. The seeds inoculation by B. japonicum UCM B-6035 strain promoted to reduce the negative impact of the Maxim Star 025 FS fungicide on the nitrogenase activity of nodulation apparatus. The positive effect of seeds bacterization was observed in the in- crease of the quantity of rhizosphere microorganisms of main ecological trophic groups. In the variant with seed treatment by Maxim Star 025 FS and Kinto duo fungicides was found a decrease in the number of microorganisms of studied groups in comparison with the control variant; the Vitavaks 200 FF fungicide application promoted to improve of these microorganisms development compared with the variant without the fungicides application and bacterization. At the inoculation of rhizobia industrial strains the negative effect of the Maxim Star 025 FS and Kinto duo fungicides to oligoazotrophic and prototrophic micro- organisms was not observed. The Conclusion. The symbiotic system of variant with the combined application of the Kinto duo fungicide with B. japonicum UCM B-6023 strain characterized by the highest nodulation and nitrogen-fixing activity.

[INFLUENCE OF FUNGICIDES COMPLEX INOCULUM EKOVITAL ON RHIZOSPHERE MICROBIOCENOSIS, DISEASES RESISTANCE AND SOYBEEN PRODUCTIVITY].

It has been investigated the effect of fungicide with systemic action of Vitavaks 200 FF, Maxim Star 025 FS, Kinto duo and the complex inoculum Ekovital on rhizospheric microbial communities, diseases resistance and soybean productivity of Annushka biovar. The combined use of fungicides and inoculation has contributed to better formation of nodulation apparatus (the number of nodules on the roots was increased in 1.3-2.8 times), resistance increase to soybean pathogens septoriosis and ascochitosis, plant productivity increase on 17.4-32.1% relatively to the variant with Ekovital. The efficiency of the combined treatment of seeds against septoriosis and ascochitosis has become 45.8-64.1% and 82.0-95.1% respectively, in the flowering-early fruiting stage and 38.1-60.6% and 70.3-82.1% respectively, in the loading beans phase.

[Effect of soil microflora on 137Cs transition to plants].

The impact of certain types of microorganisms on 137Cs transfer from the substrate into the plant was analyzed in the experiment on artificial mediums. It was found that certain types of microorganisms could either reduce or increase the ratio of 137Cs transfer from the substrate to the plant. It is shown that this property is independent of the localization of the microorganism on the surface of the root, for all the analyzed bacteria belonging to the rhizospheric group. Azotobacter chroococcum UKM B-6003 stimulated the radionuclide transfer to plants up to 1.5 times, while the best bacteria for reducing its accumulation is Burkholderia sp IMER-B1 -53 - 1.3 times in comparison with the control. It was shown that the strain Bacillus megaterium UKM B-5724 from the collection of the Institute of Microbiology and Virology of NASU has a high ability to accumulate radionuclides.

[Comparative analysis of isolation methods of DNA from rhizosphere soil for research of microbiocenosis].

The comparative analysis of different methods for the isolation of microbial DNA from ordinary black earth and dark-gray podzolic soil of soybean rhizosphere was carried out. All preparations of DNA which isolated from dark-gray podzolic soil after purification using highly dispersed silica (AppliChem, Germany) were suitable for 16S rRNA genes amplification with universal bacterial primers 11F i 1492R. For DNA extraction from ordinary black earth suitable for PCR DNA preparations were obtained using two of the six investigated methods. Isolation of DNA using a commercial Power Soil DNA Isolation Kit (MO BIO, USA) can get a small amount of DNA suitable for molecular studies without further purification procedures.

[Qualitative composition of dominating forms of microorganisms isolated from radionuclide contaminated soil and their ability to accumulate 137Cs].

Qualitative composition of the dominating forms of microorganisms isolated from radionuclide contaminated soils has been studied. The ability to accumulate 137Cs by freshly isolated species and collection cultures that were not adapted to the presence of the radionuclide has been analyzed. It is shown that among the analyzed microorganisms the greatest ability to accumulate the radionuclide is inherent in the collection culture Bacillus megaterium UKMV-5724.

[Activity of main enzymes of ammonium assimilation in Bradyrhizobium japonicum under the influence of plant flavonoid inductors].

The activity of key enzymes of ammonium assimilation in cell-free extracts of soybean rhizobia characterized with different effectiveness in symbiosis, has been researched. It has been found out that at highly efficient strain Bradyrhizobium japonicum UKM B-6035 the most active links in the system of ammonium assimilation reactions are glutamate synthase (glutamate-oxoglutarate-aminotransferase, GOGAT) and glutamate dehydrogenase (GDH). Whereas the most active links at the ineffective strain B. japonicum 21110 are glutamine synthetase (GS) and GDH. Under the influence of specific for soybean-rhizobia symbiosis flavonoid genistein (0.01 nm) GS-activity of the highly efficient strain has considerably increased (60.9 times), and this activity has exceeded the one of the ineffective strain more than twice. GDH has been activated in the presence of genistein in both researched strains. The nonspecific flavonoid naringenin has not stimulated GS-activity of the highly efficient rhizobia, but has stimulated the activity of GDH-way.

[Effect of phytoregulator reglag on symbiotic properties of Bradyrhizobium japonicum 634b].

The influence of inoculation compositions on the basis of nodule bacteria Bradyrhizobium japonicum 634b and phytohormonal plant preparation Reglalg on formation, functioning and productivity of soybean-rhisobium symbiosis was studied in the vegetation and field experiments. It was shown, that the phytohormonal component of the composition increases the nodulation and nitrogenase activity of the Bradyrhizobium japonicum 634b and effectiveness of the symbiotic system.

[Glutamate dehydrogenase activity of Bradyrhizobium japonicum in the presence of phytoregulators].

Influence of plant growth regulators ivin and emistim C, and flavonoids daidzein and quercetin on the glutamate dehydrogenase activity of soybean nodule bacteria, with contrasting symbiotic properties, were studied. It was shown that all used phytoregulators stimulated glutamate dehydrogenase activity of Bradyrhizobium japonicum 71t (the strain with highly efficient symbiotic properties) 1.2-4.9 times. Bradyrhizobium japonicum 21110 (the strain with inefficient symbiotic properties) diminished the enzyme activity in the presence of all phythoregulators except for ivin.

[Effect of plant growth regulators on physiological activity of Bradyrhizobium japonicum ].

Influence of plant growth regulators Ivin, Emistim C, Eney and Agrostimulin on the biomass production and exopolymers synthesis of soybean nodule bacteria, which have contrasting symbiotic properties, and glutamine synthetase activity of their cell-free extracts were studied. It was shown that the processes of the biomass and exopolymers accumulation had an opposite direction. Of all preparations only Ivin and Agrostimulin intensificol growth activity of the microorganisms under study. The level of glutamine synthetase activity and this enzymatic reaction specificity to the bivalent metal ions were determined by the special features of Bradyrhizobium strains and nature of the plant growth regulators. Only in the presence of Eney the increase of glutamine synthetase activity of both cultures of Bradyrhizobium japonicum was established.