Seminar: Ahto Agan | Hymenoscyphus fraxineus and Hymenoscyphus albidus on leaflets of Fraxinus excelsior

European ash has been declining since the 1990’s owing to ash dieback caused by the invasive alien ascomycete Hymenoscyphus fraxineus. Ash leaf tissues serve as a route for shoot infection but also as a sporulation substrate for this pathogen. Reports indicate that Hymenoscyphus albidus, an indigenous relative considered a harmless saprophyte in shed ash leaves, has declined along with ash dieback. In addition, knowledge of the leaf niche partitioning of F. excelsior by indigenous fungi and H. fraxineus is needed to understand the fungal community receptiveness to the invasion. We subjected DNA extracted from unwashed and washed leaflets of healthy and diseased European ash to PacBio sequencing of the fungal ITS1-5.8S-ITS2 rDNA region. Leaflets from co-inhabiting rowan trees (Sorbus aucuparia) served as a reference. To clarify spatial and temporal niche overlap between H. albidus and H. fraxineus, we used light microscopy, fungal species-specific qPCR assays and PacBio long-read amplicon sequencing to examine fungal species composition and hyphal growth in attached leaves of European ash.  

NB! Vastavalt praegu kehtivatele suunistele peavad kõik seminaril osalejad kandma maski. /  

NB! According to the current guidelines, everybody who will participate in the seminar must wear a mask.