[BACILLUS STRAINS'S SCREENING--ACTIVE ANTAGONISTS OF BACTERIAL AND FUNGAL PHYTOPATHOGENS].

Antagonistic activity 100 strains of Bacillus bacteria towards to museum and actual strains of phytopathogenic bacteria and fungy was defined. Relation between level of antagonistic activity to phytopathogenic bacteria and genus accessory of the last was shown. The medium level of antagonism to fungal phytopathogens at 30% of the studied strains of Bacillus bacteria was shown. 5 strains of Bacillus sp. with high and medium levels of antagonism to phytopathogens bacterial and fungy nature was selected and considered as perspective for creation of biological preparations for plant protection.

[Yeasts--the pathogen of weed diseases].

Plant pathogenic yeast were isolated from infected weeds that occur in cereal crops. On the basis of morphological, physiological and biochemical properties the yeast isolated from sow thistle and dandelion have been identified as Rhodosporidium diobovatum Newell & Hunter and Rhodotorula sp. In the experiment the yeast caused pathological process on the weeds, from which they are isolated, on other types of weeds, but also on wheat, oat and soybean.

[Pseudomonas syringae - the agent of bacterial diseases of weeds].

The symptoms of bacterial diseases of the associated weeds have been identified and described in the wheat crops grown in different farming systems. On the basis of its morphological, biochemical and serological properties the agent isolated from frost-blite, barnyard grass, wild radish, couch grass, bottle-brush, bindweed and sow thistle has been identified as Pseudomonas syringae. Serological affinity between the weed bacteria and the agent of bacterial diseases of cereals has been established.

[Influence of bacteria of Bacillus genus on the causative agent of bacterial cancer of tomatoes].

It has been shown that bacteria of the genus Bacillus inhibited the development of infection caused by Clavibacter michiganensis subsp. michiganensis, in tomatoes. Pre-sowing seed treatment with suspensions of Bacillus subtilis IMV B-7023 and Bacillus pumilus 3 enhanced resistance of plants to bacterial disease of cancer, probably due to the synthesis of biologically active substances with antimicrobial properties by these bacteria. Of the two strains of bacillus, differing by antagonist properties to C. michiganensis subsp. michiganensis, a significant stimulating effect on the growth and development of tomatoes was provided by the strain B. subtilis IMV B-7023, which is part of the bacterial preparations for crop production.

[Basal bacteriosis of wheat and influence of agrotechnical methods on its spread].

Monitoring of bacterial diseases of wheat was conducted allowing for different doses of mineral fertilizers and crops predecessors. It is shown that symptoms of development of the basic disease of wheat, which is caused by Pseudomonas syringae pv. atrofaciens, varied depending on agrotechnical methods, stages of plant growth and environmental factors. Introduction of different doses of nitrogen, phosphate and potassium fertilizers, especially high ones, increases the damage of wheat by the agent of basal bacteriosis P. syringae pv. atrofaciens. Strains of this pathogen, isolated from the infected wheat plants, affect in the experiment such weeds as sow thistle, field horsetail, and couch grass.

[Pseudomonas genus bacteria on weeds].

It has been shown in the work that the weeds (couch-grass and ryegrass) may be affected by bacterial diseases in natural conditions, Pseudomonas genus bacteria being their agents. The isolated bacteria are highly-aggressive in respect of the host-plant and a wide range of cultivated plants: wheat, rye, oats, barley, apple-tree and pear-tree. In contrast to highly aggressive bacteria isolated from the affected weeds, bacteria-epi phytes isolated from formally healthy plants (common amaranth, orache, flat-leaved spurge, field sow thistle, matricary, common coltsfoot, narrow-leaved vetch) and identified as P. syringae pv. coronafaciens, were characterized by weak aggression. A wide range of ecological niches of bacteria evidently promote their revival and distribution everywhere in nature.

[Serological heterogeneity of Pseudomonas syringae pv. atrofaciens strains and their ecological niches]. / Serologicheskaia geterogennost' shtammov Pseudomonas syringae pv. atrofaciens i ikh ékologicheskie nishi.

The paper deals with a comparative analysis of the serological and ecological properties of Pseudomonas syringae pv. atrofaciens strains from the collections of microbial cultures at the Malkov Institute for Plant Genetic Resources and Zabolotny Institute of Microbiology and Virology. All of the strains from the Bulgarian collection, except for one, fall into five serogroups (II through VI) of the classification system of Pastushenko and Simonovich. The P. syringae pv. atrofaciens strains isolated from Bulgarian and Ukrainian wheats belong mainly to serogroups II and IV, respectively. The strains that were isolated from rye plants belong to serogroup I. The strains isolated from sorghum and Sudan grass belong to serogroups II, IV, and VL. Serogroup III includes the P. syringae pv. atrofaciens strains that were isolated from cereals in the United Kingdom but not in Ukraine.