Novel biocontrol agents “Fungal Endophyte” for Fusarium graminearum biocontrol in maize

Fusarium Head Blight (FHB) is a devastating fungal disease which affects small grain cereals such as wheat and maize. Although FHB is caused by a species complex, Fusarium graminearum (Fg) is the most important member. Beside the economic losses due to the decrease in yield, the fungus has an impact on the quality due to the production of mycotoxins. Additionally, these mycotoxins represent a serious impact on human and animal health upon consumption of the contaminated cereals. Driven by the awareness that reduced tillage systems result in soil structure improvement, conservation tillage practices are often implemented leaving more stubble/straw residues on the field. This organic material can serve as the primary inoculum of Fg. Over the last decade, different strategies for FHB management have been proposed. Biological control using beneficial or non-pathogenic bacteria and fungi is encouraged as it is a safe and sustainable longterm solution in comparison with chemical control. Although crop residues serve as primary inoculum of Fg, we hypothesize that these crop residues also harbor valuable antagonistic fungi which might be used as biocontrol agents. In the current project, several novel fungal endophytes have been isolated, from European and African crop residues, and tested for their ability to control the growth of Fg and the production of its mycotoxins in vivo and in vitro. New isolates of Sordaria spp., Clonostachys spp., Epicoccum spp., and others were tested for their effects against Fg. In vitro plating assays (contact and volatile) and in vivo, maize pot experiments, have been performed for each isolated species to assess their biocontrol capacity against Fg. The obtained results indicate that the selected biocontrol agents have a promising effect on Fg infection. Furthermore, the selected biocontrol agents have an inhibitory effect on levels of mycotoxins (deoxynivalenol,15-acetyldeoxynivalenol, 3-acetyldeoxynivalenol and zearalenone) measured through a validated multi-mycotoxin LC-MS/MS method production. Using a non-targeted approach, with Q-TOF LC/MS, the mechanism of action is being investigated: whether there is a detoxification effect and/ or inhibitory volatiles or other substances that may have an effect on the fungus metabolism. The project will contribute to a great extend to reduction of fusarium mycotoxins level in grain cereals especially wheat and maize