Globodera rostochiensis (Woll.) Behrens (Tylenchida, Heteroderidae), the only potato cyst nematode species found in Finland

About 10000 soil samples, 519 thereof infected with potato cyst nematode (PCN), were studied during 1984-1988. Cysts from infected samples were tested by isoelectric focusing to identify PCN species. All the infected samples were also tested with H1-resistant (Satuma) and susceptible (Bintje) potato cultivars to separate resistance breaking populations. Cysts from the roots of Satuma were tested by two-dimensional electrophoresis. The potato seed production area in Finland was found to be free of PCN of any kind. In other parts of Finland all tested samples revealed G. rostochiensis banding pattern, but no G. pallida was found. Except for the most common pathotype Ro1-Ro4, we only found Ro2