Genetic diversity of Heterobasidion spp. in Scots pine, Norway spruce and European silver fir stands

Investigations of genetic diversity of Heterobasidion spp. in Scots pine, Norway spruce and European silver fir stands indicated that almost all of identified genets occurring in those stands were small and occupied only a single stump. In some cases two, three or even four genets could effectively exist in an individual stump. Genetic similarity of H. annosum s.s. genets varied from 0% to 62%, H. parviporum from 0% to 38% and H. abietinum from 0% to 55%. The oldest and biggest genet was found in laying fir log and overgrew the wood for at least 14 years. This genet belonged to H. abietinum. The size of genets was related to thinning operation, spore dispersal, age of stand or competition in wood colonization