Prevalence and diversity of pathogen-like endophytic fungi from wild grasses and sedges of Iran’s Hyrcanian forests

The diversity of mycoflora associated with grass and sedges belonging to 24 species of eight plant families inhabiting three regions of the Hyrcanian Forest in Iran was surveyed. Fungal isolates were recovered from the roots, stems and leaves of plants, and ITS sequences of ribosomal DNA were determined. The 113 fungal isolates were categorized into the lowest taxonomic rank possible. Surprisingly, pathogen-like fungi encompassed 34% of the endophytic isolates. Colletorichum, Fusarium, and Alternaria, all genera containing important pathogenic species, were abundant. Occurrence of Fusarium was highest in root tissues, while Colletotrichum appeared more dominant in leaves and stems. Wheat seedlings were exposed to inocula of 25 of these endophytic isolates. Eleven isolates inhibited growth of the seedlings, whereas 14 isolates promoted growth compared to uninoculated controls. Further, wheat seedlings treated with isolates reported as etiological agents such as Parastagonospora nodorum and Fusarium sp., promoted growth. We report first-time isolation of Darksidea sp., a genus of root-colonizing dark septate endophytes (DSE), from herbaceous vegetation of Hyrcanian forests of Iran.