Culturable Endophytic Fungi in Fraxinus excelsior and Their Interactions with Hymenoscyphus fraxineus

The species diversity of culturable endophytic fungi was studied in the leaves and twigs symptomatic asymptomatic Fraxinus excelsior trees. Endophytic mycobiota dominated by Ascomycota species, with Pleosporales (44.17%) Diaporthales (23.79%) endophytes being most frequently observed tree samples. number isolates richness varied depending on sampling date (May October) tissue location. Of 54 identified based ITS sequences, 14 were classified as dominant. isolated Diaporthe eres, followed Alternaria alternata, Dothiorella gregaria, Fraxinicola fraxini. inhibitory effect 41 (75 isolates) radial growth a Hymenoscyphus fraxineus isolate under vitro conditions (dual cultures). H. inhibited four from (Fusarium lateritium, Didymella aliena, macrostoma, gregaria). also planta conditions. artificially inoculated into trunks ash trees reduced length necroses formed co-inoculated same trunks. This depended isolate, inhibition prominent only F. lateritium D. aliena. Although total necrotic lesions infection shorter endophytes, difference not significant.