STUDY OF PATHOGENICITY OF FIELD STRAINS OF XANTHOMONAS CAMPESTRIS BACTERIA

Gram-negative bacterium Xanthomonas campestris, which is the causative agent of bacterial diseases of many cultivated plants, annually leads to significant economic losses in many sarans of the world. The development of modern methods of combating this phytopathogen is an urgent task for agriculture. One of the promising methods is the use of bacteriophages, the selection of which requires working directly with bacteria that have pathogenic properties in relation to natural host plants. This paper presents the results of studying the pathogenicity of the existing collection of microorganisms in relation to various varieties of cabbage. 38 strains of Xanthomonas campestris bacteria were used as the object of the study. The pathogenicity of the selected crops was studied by methods of studying hypersensitivity on tobacco plants and by infiltration into natural host plants. Studies have shown that the bacteria had varying degrees of activity in relation to cabbage varieties F1, Agamer 611 and Siberian 60. At the same time, 21 of the 38 strains studied showed their pathogenic properties on plants of all three varieties. In most cases, characteristic V-shaped lesions were found on the leaves of plants, which eventually led to the withering of the entire leaf. In some cases, necrosis was observed at the sites of inoculation of the studied strain of bacteria. Analysis of the time of manifestation of symptoms of bacteriosis showed that strains previously isolated from affected plants visually showed their pathogenic properties 5-6 days earlier than strains isolated from seed material. The obtained results will be used in the future to select bacteriophages with the greatest spectrum of action against bacteria with pathogenic properties.