Fungal endophyte Epicoccum nigrum 38L1 inhibits in vitro and in vivo the pathogenic fungus Fusarium graminearum

Abstract

Wheat (Triticum aestivum L.) and its products constitute a major part of the daily human and animal diet. However, Fusarium head blight caused by Fusarium graminearum is one of the most devastating fungal diseases in wheat. In this study, a fungal endophyte strain 38L1 was newly isolated from leaf of maize (Zea mays L.) and identified as Epicoccum nigrum using molecular phylogenetic analysis of the rDNA internal transcribed spacer (ITS), large subunit ribosomal RNA (LSU) and beta-tubulin (TUB) gene sequences. In dual cultures and double plate assays, strain 38L1 markedly inhibited the mycelial growth of F. graminearum strain PH-1 and four other pathogenic fungi including Botrytis cinerea strain P-1, Colletotrichum gloeosporioides strain Y-3, Botrytis cinerea strain F-2, and Sclerotinia sclerotiorum strain D-4, indicating a broad antifungal activity. Besides, culture filtrates of strain 38L1 indicated a high fungicidal effect resulting in a significant reduction of mycelial growth, mycelial biomass and spore germination of F. graminearum strain PH-1. Furthermore, the application of conidial suspensions and/or culture filtrates of E. nigrum strain 38L1 with spore suspensions of F. graminearum strain PH-1 on wheat spikes resulted in a significant biocontrol efficacy of Fusarium head blight in growth chamber and field conditions. Hence, these results suggest that E. nigrum strain 38L1 could be a potential biocontrol agent against F. graminearum strain PH-1 in vitro and in vivo.