Genetic variation within Gremmeniella abietina var.
abietina was studied using the Random Amplified
Microsatellite-technique (RAMS). Ninety-three isolates were
investigated, originating mostly from Finland, but also from Canada,
U.S.A., Japan, Norway, Italy, Iceland and Sweden. Four banding pattern
types were observed corresponding to the present division of this
species in Asian, North American and two types of European races.
Furthermore, an additional banding pattern was also observed.
Intraracial variation was observed within all races, the North
American one being the most polymorphic. Isolates of the large tree
type (LTT) Gremmeniella from North America, Italy and Iceland
contained RAMS alleles not observed in Finland, Sweden or Norway.
Therefore, the isolates of LTT Gremmeniella should not be
transported even within the area of its natural occurrence.