## Materials and Methods
### Influence of pesticides on the growth and morphology of colonies of phytopathogenic bacteria  
To determine the effect of the pesticides on _P. syringae_ pv. _tomato_ LB Broth (Lennox) was used. The studied compounds were introduced into the LB medium, into which phytopathogenic bacteria had been already inoculated. After 48 h of cultivation at 28 \({}^{\circ}\)C, several series of 10-time dilutions were plated on potato agar (PA) [18] to count the number of bacterial cells (CFU/mL) and determine the ability of pesticides to induce morphological dissociation in phytopathogenic bacteria. Morphology and structure of bacterial colonies were studied in 48-72 h after plating on PA. The size of the colonies, their shape, structure and consistency, surface, profile, edges, colour were characterised. Physiological and biochemical properties of bacteria were studied by well-known methods [19].  
**Detection of streptomycin resistance mutations in phytopathogenic bacteria.** The mutagenic activity of pesticides against phytopathogenic bacteria was recorded as an increase in the number of streptomycin resistance mutations during cultivation on the medium containing the pesticide. For this purpose, 0.1 mL of bacterial cell suspension (10\({}^{9}\) CFU/mL) was plated on PA containing pesticide and streptomycin (10 \(\mu\)g/mL). After 48 h of cultivation at 28 \({}^{\circ}\)C, the number of streptomycin-resistant (Str\({}^{\text{R}}\)) colonies was counted. Mutagenic effect of pesticides was estimated by increasing the number of Str\({}^{\text{R}}\) colonies formed on the medium with pesticide and streptomycin in comparison with the number of Str\({}^{\text{R}}\) colonies that grew on the medium with streptomycin only [15].  
**Serological methods.** The belonging of R form and Str\({}^{\text{R}}\) mutants to _P. syringae_ was established by serological methods. For the microagglut reaction on a glass slide, a drop of antiserum at the dilution of 1:10 or 1:20 and a drop of saline were applied. Into each drop, a small amount of bacteria was inserted and mix to form a barely visible turbidity. In 1-2 min, in the case of a positive reaction, the gluing of bacteria into conglomerates was detected. Only in the control drop, the uniform suspension of bacteria without gluing was observed [19].  
**Hypersensitivity reaction on tobacco leaves.** The ability of S and R forms of _P. syringae_ to induce the hypersensitivity reaction was determined using the method of injection-infiltrations on the leaves of _Nicotiana tabacum_[19]. To do this, a suspension of cells of two-day cultures of the studied bacterial strains with a concentration of \(1\times 10^{7}\) CFU/mL was introduced under the leaf epidermis. The suspension of cells was prepared on sterile tap water. As a negative control, under the epidermis of the leaf, sterile tap water was introduced. The presence of necrosis was observed in a day.  
**Statistica.** Statistical processing of the research results was performed using the STATISTICA v. 6.0 application software package, which, according to the Student t-test, were statistically significant at the significance level \(p\leq 0.05\).