Intersterillity groups (ISG) of Heterobasidion annosum in the Italian Alpine region and Austria : Poster-Abstract : Root and Butt Rots of Forest Trees

1998

S. 437

Bandaufführung

9207S

103685

Heterobasidion annosum is one of the most important fungal parasites of conifer trees in the Alpine region were borth the main hosts and all the three intersterility groups (ISG) of the pathogen, F, P and S, are growing under nearly optimal climatic conditions. After several surveys the fungus has been collected from natural forests and artificial stands both from Norway spruce (Picea abies) and Silver fir (Abies alba) on the Italian slope of the Alps and in some localities of Austria. Occasionally the pathogen was found also on Scots pine (Pinus sylvestris) and larch (Larix decidua) trees. The intersterility group of the isolates was determinet by pairing the cultures with homokaryon testers in Petri dishes. As a rule each group was colonizing mainly its typical host, on Silver fir 95,5% of the isolates wre F type. 3,6% S and 0,9% P. On pine all the isolates collected were P type. 71,7% of the isolates collected from Norway spruce were S type, and 1,% P. In some areas and particularly in Austria F group was frequently detected on Norway spruce (26,5% of the isolates belonged to the F type), apparently as a saprophytic stump colonizer.