Morphological and Genetic Diversity of Cercospora beticola Isolates

The fungus Cercospora beticola Sacc. is the one of the most important pathogens on the sugar beet. This plant pathogen causes cercospora leaf spot disease which is a serious economic problem for growers of this crop all over the world. Traditionally, the identification of C. beticola is based mainly on conidial characters and host association, but today molecular characterization is necessary for determination of their genetic diversity. This study was designed to evaluate level of morphological and genetic diversity of population C. beticola in Serbia. Isolates originated from sugar beet field where this crop has been cultivated for last two decades and from localities where sugar beet has never been cultivated. The isolates exhibited significant morphological differences in shape, colour and size of border zone of colony on different nutrition media. For molecular identification and characterization of these isolates we used molecular tools: Polymerase Chain Reaction (PCR), Random Amplified Polymorphic DNA (RAPD) and Direct Amplification of Minisatellite-region DNA (DAMD). The ability of random amplified polymorphic DNA (RAPD) to distinguish among C. beticola populations from Serbia was evaluated. Certain specific bands were identified which could be effectively used to distinguish the populations. Polymorphism in RAPD markers among C. beticola populations was high and sufficient to distinguish each of the populations. The results obtained suggest that RAPD and DAMD markers are valuable for the genetic divergence estimation in C. beticola and for the study of diversity among populations. Results of morphological and molecular tests showed the presence of different populations of C. beticola in Serbia.