EN
Cercospora leaf spot caused by fungus Cercospora beticola is the most serious foliar disease of sugar beet in Poland. The disease has a large negative impact on yield and quality of crops. A wide range of physiological and morphological diversity of this species was described. For most Cercospora species, including C. beticola sexual stage was not found, despite of determinate two matting types within populations of isolates. The aim of the study was asses genetic diversity of C. beticola isolates collected from sugar beet producing area in Poland during 2007–2008. A genetic study was performed by RAPD methods. They indicate a high level of variability of tested isolates. There was no correlation between RAPD and ISSR profiles of isolates and their origin. The high level of genetic diversity can be connected with increasing of fungicide resistance of C. beticola isolates.