Genetic Diversity of Epicoccum nigrum and its Effects on Fusarium graminearum

Epicoccum nigrum is a saprophytic or endophytic fungus that is found worldwide. Because of the antagonist effects of E. nigrum on many plant pathogens, current studies on E. nigrum have focused on the development of biological control agents and the utilization of its various metabolites. In this study, E. nigrum was collected from a wheat field, and its genetic diversity was analyzed. Phylogenetic analyses identified 63 isolates of E. nigrum divided into seven groups, indicating a wide genetic diversity. Isolates antagonized the wheat pathogen Fusarium graminearum, and reduced disease symptoms caused by F. graminearum in wheat coleoptiles. Moreover, pretreatment of wheat coleoptiles with E. nigrum induced the upregulation of pathogen-related (PR) genes, PR1, PR2, PR3, PR5, PR9, and PR10 in wheat coleoptiles responding to F. graminearum invasion. Overall, this study indicates that E. nigrum isolates can be used as biological pathogen inhibitors applied in wheat fields.