Polymorphism of microsatellite DNA was recorded for both species Phytophthora plurivora (syn P. inflata), and P. taxon salixsoil in water samples, which may suggest that investigated isolates differ and present the genetic richness leading to the potential adaptation in new environments. Results showed that locus S29-30 could be useful for analysis of Phytophthora species diversity. High polymorphism of microsatellite DNA was recorded for both species P. plurivora and P. taxon salixsoil. It may reflect the high potential of adaptabilityof P. plurivora to the changing environmental conditions. As they are distributed with the system of Polish rivers they may cause threat for many forest tree species.

Key words: microsatellite DNA markers, P. plurivora,P. taxon salixsoil, genetic variability