Survey of fungal endophytes in barley under Fusarium head blight infection

Fusarium head blight (FHB) is a devastating fungal disease caused by <i>Fusarium graminearum</i>, which affects barley (<i>Hordeum vulgare</i> L.) and other small cereal grains. Fungal endophytes are microorganisms that reside inside tissues and considered that they may have been involved in various roles of the plants. This study involved the comparison of fungal endophytes between "non-infected/clean" and "FHB-infected" barley genotypes in various tissues collected at different plant developmental stages and were grown under different conditions (i.e., greenhouse, research field, and FHB-field nursery). We hypothesized that fungal endophytes diversity and abundance may differ between plant tissues in various barley genotypes that were non-infected and FHB-infected. The 18S-internal transcribed spacer sequencing analysis revealed a greater number of fungal operational taxonomic units (OTUs) and endophyte species in FHB-infected barley compared to clean barley. A one-way ANOVA and Tukey's pairwise comparison test (<i>p</i> ≤ 0.05) were performed to test significant differences. Higher seed endophyte diversity was found in FHB-infected (120 OTUs) compared to non-infected (113 OTUs) harvested in 2021. The increase in diversity of endophytes that contributes to different roles in plant protection and defense, such as biocontrol agents, may prevent the growth of <i>Fusarium</i> species and decrease FHB-infection.