[Antagonistic acttvity of Bacillus amyloliquefaciens strains--potential biocontrol agents for cereal crops].

The antagonistic activity of strains Bacillus amyloliquefaciens YKM B-7243 and YKM B-7404 against bacterial and fungal agents of winter wheat diseases was demonstrated. Low antagonistic level against bacterial agents of plant diseases was shown. Antifungal activity of strains against agents of winter wheat was on the low level. High biological efficiency was shown under binary compositions of the studied strains. It was concluded that the enhancing of fungicide and growth-stimulation effects in binary compositions were found.

Micromycetes associated with wheat diseases in different regions of Ukraine.

The study is largely concerned with the micromycetes that represented the causative agents of harmful diseases of wheat and are severe challenges for grain producers in Ukraine. The potential yield of domestic commercial cultivars is 11-12 t/ha, but only 25-40% of their productivity is realized One of the main factors reducing the yield is ineffective disease control. Eyespot, take-all and sharp eyespot are among the most important diseases of wheat in Ukraine. However they are still underestimated in the country because of difficulties in their detection and causal agent isolation. Results of analysis of 37 Oculimacula strains, causal agents of eyespot, show the prevalence of the O. acuformis in northern regions, O. yallundae - in the south. Both species were detected in the central regions. The wide distribution (up to 100%) of Ceratobasidium cereale, a causal agent of sharp eyespot, has been observed all over the country. Gaeumannomyces graminis var. tritici, a causal agent of take-all, has been detected among darkly pigmented soil-borne fungi. Seed infection has been mainly presented by Alternaria, Fusarium, Penicillium, Helminthosporium and Mucor species. Pathogenicity of Fusarium strains has been confirmed in pathogenicity tests. The information has been obtained during surveys of winter wheat crops under different climatic conditions of Ukraine.

[Synthesis of extracellular phythohormones by Bacillus strains isolated from different ecological sources].

Synthesis of extracellular phytohormones by bacteria strains of the genus Bacillus isolated from different ecological sources (soil and plant) has been researched. It has been shown that phytohormone's synthesis ability of the endophytic and free-living Bacillus strains is significantly different as regards the level and spectrum of synthesized compounds. It was concluded that such differences in synthesis of extracellular phytohormones by bacilli are associated with different type of interactions between the studied microorganisms and host plant.