EN
Recent years have seen a great increase of interest in application of molecular biology methods (hybridization of nucleic acids, polymerase chain reaction and ligase chain reaction) in the diagnostics of plant bacterial diseases. These methods are incomparably more sensitive than the traditional and the serological ones, thus making possible detection and correct identification of even low number of bacteria and, what 18 most important, results are obtainable in a significantly shorter time - even in a few hours. The paper reviews the most recent literature concerning applications of molecular methods to detection of bacteria belonging to genus: Agrobacterium, Clavibacter, Erwinia, Pseudomonas and Xanthomonas. A serious disadvantage of these methods is their high cost resulting from the need for expensive laboratory equipment and chemicals. Another drawback is the use of hazardous materials such as ethidium bromide (PCR) and radioactive isotopes (hybridization, LCR). Nevertheless, the molecular methods are more and more commonly used in phytopathological laboratories, especially in those examining quarantine objects. They are particularly useful as an assisting tool when results of traditional and serological tests are equivocal.