EN
Armillaria root disease is one of the most important diseases causing losses in forestry, horticulture, pomiculture and agriculture. Fungi from Armillaria spp. infest roots and stem base in trees and shrubs, causing white wood rot. In Poland the most common species include Armillaria ostoyae (Romagn.) Herink, found both in coniferous and deciduous stands, and A. gallica Marxm. et Romagn. found in deciduous stands. Identification of antagonistic interactions between microorganisms in the soil medium enables to use their activity to protect plants against pathogens. Analyses were conducted on two Trametes versicolor isolates TR31 and TR55, collected from oak stumps, and 5 fungal species from the genus Armillaria: A. borealis Marxm. et Korhonen, A. cepistipes Velen., A. gallica, A. mellea (Vahl) P. Kumm. and A. ostoyae. Profiles of volatile compounds produced by T. versicolor isolates TR31 and TR55 determined in this study varied in their effect on growth of pathogens Armillaria borealis, A. cepistipes, A. gallica, A. mellea and A. ostoyae. TR31 more effectively than isolate TR55 inhibited growth of fungi from the genus Armillaria. Profiles of volatile compounds biosynthesised in the examined fungal cultures were assessed by headspace microextraction in a gas chromatograph coupled with a mass spectrometer. We detected 179 compounds in the analysed fungal cultures. They belonged to the following groups of chemical compounds: amines, alcohols, terpenes, aldehydes, ketones, hydrocarbons, heterocyclic compounds, esters and aromatic compounds (tab. 2). The most numerous group among the isolated volatile compounds comprised hydrocarbons, alcohols and esters at 32.4%, 16.2% and 14.5%, respectively. The highest concentrations reported in RU (i.e. the peak area of a given substances in relation to the peak area of the internal standard, i.e. tridecane) were recorded for aldehydes, alcohols and hydrocarbons. Among all the identified volatile compounds the highest concentration was observed for 2−methylbutanal. However, it was characteristic only of isolate TR31, which exhibited a greater capacity to inhibit growth of Armillaria spp. in comparison to isolate TR55 (fig.).