Rapid detection of fungal endophytes in grasses for large‐scale studies

Summary Standard visual screening methods for determining the qualitative and quantitative presence of fungal endophytes are too time‐consuming for large‐scale ecological studies. We investigated whether commercially available immunoblot kits, using monoclonal antibody techniques and designed for rapid‐screening of the presence of Neotyphodium endophytes in fresh samples of the pasture grasses Festuca arundinacea and Lolium perenne , could be used for Neotyphodium detection using other grasses and preserved samples. We also determined whether immunoblot kits could provide quantitative information about the amount of Neotyphodium in the grass. The kits accurately detected endophyte presence in F. rubra , F. ovina , F. pratensis and F. altaica , in both preserved samples (dried and fixed), including 12‐year‐old stored, dried samples of F. rubra . Endophytes were detected in 7‐day‐old seedlings of Lolium perenne , 3 days (30%) earlier than previously recognized. The intensity of the coloured tissue prints on scanned immunoblot cards was significantly positively correlated with hyphal density, demonstrating a previously unrecognized accurate quantitative application. These findings greatly reduce logistical barriers to large‐scale field research into the broader ecological significance of Neotyphodium in temperate and arctic grasses in non‐agricultural ecosystems (particularly in remote areas) and suggest potential for estimating historical infection rates using stored and herbarium specimens.