Isolates of Tiarosporella parca from needles of Picea abies growing in Lapland, southern Finland, southern Norway and Switzerland were compared with each other by using their combined fatty acid and sterol profiles (FAST) and randomly amplified microsatellite (RAMS) markers.

Nineteen fatty acids and four sterols were recorded, nine of which appeared only at low amounts (<1% of the total amount of extractives). In a discriminant analysis of their FAST-profiles the isolates could be separated into three non-overlapping groups: (i) Lappish and southern Norwegian, (ii) Southern Finnish and (iii) Swiss isolates. The Swiss isolates form the most distinct group with 11 out of 23 extractives significantly different from those of the other geographical populations.

In RAMS analysis two out of five primers tested with ten isolates resulted in polymorphic banding patterns. Using these two primers 26 variable markers in eight size areas were observed which allowed separation of the 39 isolates investigated into 35 different haplotypes. Thus, only four pairs of identical isolates were observed. Determination of the genetic diversity among the isolates revealed that 59% of variation was due to variance within populations, 27% was due to variance between populations within geographical regions and 13% was due to variation between regions.

Hence, both methods show a differentiation of the European T. parca population according to geographical origin.