Forster, B.; Knizek, M.; Grodzk:i, W. (eds.) 1999: Methodology of Forest Insect and Disease Survey in Central Europe. Proceedings of the Second Workshop of the IUFRO WP 7.03.10, April20-23, 1999, Sion-Chateauneuf, Switzerland. Birmensdorf, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) 278. The occurrence of Cenangiumferruginosum Fr. (Ascomycota) as an endophyte from the needles of Austrian pine in Slovenia Dusan Jure*, Maja Jure**, Vesna Rajh* * Slovenian Forestry Institute, Department of forest protection and wildlife ecology, Vecna pot 2, 1001 Ljubljana, Slovenia ** University of Ljubljana, Biotehnical Faculty, Department of Forestry and Renewable Forest Resources, Vecna pot 83, 1001 Ljubljana, Slovenia. Abstract Isolations of endophytic fungal populations from green symptomless needles of Austrian pine conducted in natural stands and plantations in Slovenia establish that after Cyclaneusma niveum (Pers.:Fr.) DiCosmo, Peredo & Minter, Cenangiumferruginosum Fr. with isolation frequency of 6% (N=5592) is the most numerous fungus. It was isolated from the samples of all collected sites, the infection rate varied from 2,73% to 10,42%; on young trees it was 7,16% and in old trees it was 5,64%. The number of infections increased with needle age. It was predominantly isolated from the middle part (45,6%, N=336) and the tip (32,7%) of the needles, the basal part was less infected (21,7%). C.ferruginosum could not be isolated from buds. The results suggest that the needles represent reservoirs for the fungus from where it can spread to the twigs when environmental conditions change to the advantage of the fungus and/or the disadvantage of the host. Key words: endophytic fungi, Cenangium ferruginosum, Pin us nigra, drought stress 278 .