Phylogenetic relationship and taxonomy of a hybrid Epichloë species symbiotic with Festuca sinensis

More than 40 unique taxa in genus Epichloë that form associations with grasses in the subfamily Pooideae have been described based on morphology, host specificity, and phylogenetic analyses. In this study, a new Epichloë species, Epichloë sinensis sp. nov., was isolated from seeds of endophyte-infected Festuca sinensis that were collected from northwest China. This endophyte has typical morphological characteristics of the Epichloë genus. Endophyte hyphae are long, thin, septate, a little curved, and sparsely branched in seed aleurone layer and are orientated longitudinally and parallel to each other without branching in the intercellular spaces of leaf sheaths. On potato dextrose agar (PDA), colonies are smooth, cottony, and white. Phylogenetic relationships showed that E. sinensis was an asexual interspecific hybrid of Epichloë poae and Epichloë sibirica based on intron sequences of housekeeping genes for β-tubulin (TUBB) and translation elongation factor 1-α (TEF1-α). The alkaloid chemotype analysis showed that this E. sinensis may have the ability to produce lolitrem B and peramine. These morphological and phylogenetic characteristics supported the designation of isolates from F. sinensis as a new interspecific hybrid species.