EN
Bacteria of the genus Pseudomonas are often components of bioproducts designed to enhance the condition of the soil and plants. The use of Pseudomonas bacteria in bioproducts must be preceded by the acquisition, characterization and selection of beneficial strainsliving in the soil. A prerequisite for the selection of bacterial strains for use in bioproducts is to be able to identify the isolates rapidly and accurately. To identify and differentiate 15 bacterial isolates obtained from the soil surrounding the roots of sour cherry trees and to assess their genetic similarity, the rep-PCR technique and restriction analysis of the 16S rRNA gene and the 16S-ITS-23S rRNA operon were used. In addition, a sequence analysis of the 16S rRNA gene was performed. The analyses made it possible to divide the isolates into four clusters and to confirm their affiliation with the Pseudomonas species. RFLP analysis of the 16S-ITS-23S rRNA operon enabled greater differentiation of the isolates than RFLP of the 16S rRNA gene. The greatest differentiation of isolates within the clusters was obtained after using the rep-PCR technique. However, none of the techniques was able to discriminate all the isolates, which indicates very high genetic similarity of the Pseudomonas isolates found in the same sample of soil from around the roots of sour cherry trees. The tests performed will find application for distinguishing and identifying Pseudomonas strains collected from the soil in order to select the most valuable bacterial strains that produce beneficial effects on plants.