GENETIC DIFFERENTIATION IN FOMITOPSIS-PINICOLA (SCHWARTS, FR) KARST STUDIED BY MEANS OF ARBITRARY PRIMED-PCR

Genetic variation within and among one Finnish and three Swedish popul ations of Fomitopsis pinicola (Schwarts:Fr.) Karst. were studied by am plifying DNA from haploid isolates originating from single spore cultu res using two arbitrary primers. Analysis offspring from single fruit bodies revealed only three pairs of codominant alleles among 42 variab le genetic markers, the remaining 38 segregated independently. Genetic similarity was measured in terms of Euclidean distance. Individuals i n the Finnish population tended to form a distinct cluster in the prin cipal component analysis. Variation within and among populations/regio ns was partitioned by Analysis of Molecular Variance - AMOVA. Within p opulation variation accounted for 91.6% of the total genetic variation . The remaining 7.68% was accounted for by variation between the Finni sh population and each of the three Swedish ones. Variation among the Swedish populations accounted for only 0.72% of the fetal variation. W right's F-st was 0.17 for all. four populations and 0.13 for the three Swedish populations. These relatively low values indicate that there is gene flow among all populations or that they are derived from a com mon ancestral population. The observed pattern of genetic variation is probably the result of effective spore dispersal and the continuous d istribution of this common early successional species.