Beschreibung:
<jats:p>Investigations of genetic diversity of <em>Heterobasidion</em> 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 <em>H. annosum</em> s.s. genets varied from 0% to 62%, <em>H. parviporum</em> from 0% to 38% and <em>H. abietinum</em> 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 <em>H. abietinum</em>. The size of genets was related to thinning operation, spore dispersal, age of stand or competition in wood colonization.</jats:p>