EN
Selection of Fusarium sambucinum reizolates for high aggressiveness to potato tubers was conducted from 2000 to 2009. Five potato cultivars were used in the study: Bzura, Denar, Hinga, Irys and Tara. In 2000–2007, the differences in aggressiveness between reisolates were significant for all potato cultivars tested. Selection towards high aggressiveness of F. sambucinum reisolates in 2000–2007 probably caused the lack of significant differences in 2008 and 2009. It was confirmed also by a smaller range of infection degree and smaller standard deviation than observed in 2000–2007.