The Epichloë endophytes associated with the woodland grass Hordelymus europaeus including four new taxa

Abstract

Epichloë endophytes (Clavicipitaceae, Ascomycota), including asexual forms placed in Neotyphodium, are common in cool-season grasses. Here we characterize the endophytes of the European woodland grass Hordelymus europaeus based on growth characteristics, morphology of conidiophores and conidia and phylogenetic relationships. Of the six different taxa found on H. europaeus, four are new, for which we propose the species names E. hordelymi, E. disjuncta, E. danica and subspecies E. sylvatica subsp. pollinensis. The other two are assigned to previously described E. bromicola and E. sylvatica. E. hordelymi, E. disjuncta and E. danica are asexual interspecific hybrids, while the other taxa are haploid. Only E. sylvatica subsp. pollinensis was found to reproduce sexually on H. europaeus. The high diversity of endophytes may be explained by repeated host jumps to H. europaeus with and without subsequent interspecific hybridizations.

• Clavicipitaceae
• cool-season grasses
• interspecific hybrids
• Neotyphodium

Acknowledgments

We thank O. Putallaz and S. Rieben, former master students at ETH, for providing colony growth data and photographs, and S. Güsewell (ETH Zürich) for help with statistical analyses. Sequence data were generated in the Genetic Diversity Centre of ETH Zurich (GDC). We acknowledge the administration of the Parco Nazionale del Pollino, Parco Nazionale della Sila, Parco Nazionale del Cilento e Vallo di Diano and Länsstyrelsen Kalmar Län for permission to collect plant material in their territories.

This research was supported by a grant of the Swiss National Science Foundation ( 31003A-117729).