FUNGAL ASSEMBLAGES IN STEM AND TWIG LESIONS OF QUERCUS-ROBUR IN SWITZERLAND

Fungal assemblages present in necrotic tissues of Quercus robur were d etermined at two sites in Switzerland. Fungi were identified by examin ation of fruitbodies or by isolation. Assemblages differed with locati on (stem or twig), tissue source (xylem or bark), method of defection (isolation or inspection), stage of damage, and between sites. Dominan t fungi in stem lesions were Amphiporthe leiphaemia, Pezicula cinnamom ea, Phomopsis quercella, Fusarium sp., and Dichomera saubinetii. In di seased twig tissues A. leiphaemia and Colpoma quercinum, Fusarium sp., and P. cinnamomea were the most common. It is suggested that the lesi ons were induced by drought followed by a high frost incidence but tha t fungi may have been contributory.