Diversity assessment of endophytic fungi isolated from Euonymus japonicus

Endophytes that live with plants in a mutualistic symbiosis can be promising biological agents to improve biotic resistance. In this study, 157 endophytic fungi isolates were obtained from from root, stem, and leaf segments of E. japonicus, and they were grouped into 2 phyla, 4 classes, 9 orders, and 26 genera based on characterization of morphological features and variances of ITS1, ITS2, and 5.8 s nrDNA sequences, the Genbank accession numbers of 79 representative endophytic fungi were from MT919117 to MT919195. Of 157 islotates, Ascomycota (99.4%), Sordariomycete (64.3%), Hypocreales (26.8%), and Colletotrichum (14.7%) were the most abundant phylum, class, order, and genus, respectively. The isolation frequency, Species richness(S), Shannon index of diversity (H`) was significantly higher in root than in stem and leaf. Among them, 15 strains exhibited various levels of antagonicstic abilities against two major pathogens, Colletotrichum gloeosporoides and Neopestalotiopsis foedans of E. japonicus, and three others of Botrytis cinerea, Phomopsis sp. and Botryosphaeria dothidea. The isolate ER15, which was classified as Trichoderma sp., exhibited the strongest level of antifungal effect with up to 70% of growth inhibition against these six pathogens in a dual culture assay. These results suggest that ER15 could have potential applications in Anthracnose and branch blight control of E. japonicus.