FUNGISTATIC EFFICIENCY OF PHENOLIC-COMPOUNDS IN SPRUCE (PICEA-ABIES [L] KARST) AND INFLUENCE OF SO2

The paper deals with fungistatic phenols in Norway spruce (Picea abies). Phenolic substances were isolated from several tissues and chromatographed by TLC. Detected by bioassay using Cladosporium cucumerinum, the most fungistatic compound was isolated and identified by UV-, mass- and NMR-spectra as the stilbenglucoside isorhapontin. The highest amounts of isorhapontin were found in a 15-year-old spruce in the bark of root (1.3%) and stem (0.4%), and also in fine roots (0.3%). Sapwood contained between 0.001 and 0.01% of this stilbene (all values related to green weight). The brown-rot fungi phaeolus schweinitzii and Fomitopsis pinicola showed a depression of growth related to the concentration of isorhapontin on malt agar. Growth reduction of 50 % was reached at a concentration of 1.25 mM (F. pinicola) and 3 mM (P. schweinitzii). The white-rot fungi Trametes versicolor, Heterobasidion annosum, and Armillaria ostoyae were not inhibited. First investigation results 6 months after long-term SO2-treatment (0.28-0.34 ppm) of cloned spruces showed a reduction of fungistatic stilbenes in fine roots and bark compared with untreated controls (indirect effect).