Epichloë elymi is a haploid sexual species of fungus in the genus Epichloë (family Clavicipitaceae). It is a systemic, seed-transmissible endophytic symbiont of cool-season grasses.
Taxonomy and Description
The species was first described in 1999 by Christopher L. Schardl and Adrian Leuchtmann in the journal Mycologia, as part of a study describing three new Epichloë species symbiotic with North American grasses. The specific epithet elymi refers to its association with grasses of the genus Elymus. It is a sister lineage to Epichloë bromicola.
Host Range and Distribution
Epichloë elymi is found in North America. It has been identified in several grass species, including Elymus virginicus, Elymus patula, Elymus hystrix, Elymus canadensis (Canada wildrye), and Bromus kalmii. The species exhibits host specificity, being naturally associated primarily with Elymus species.
Reproduction and Transmission
Epichloë elymi is capable of both horizontal transmission (via sexual reproduction through the formation of stromata on host inflorescences, which produce contagious ascospores) and vertical transmission (via systemic infection of host seeds). The fungus produces stromata on some but not all infected inflorescences, placing it along a continuum from antagonistic to mutualistic symbiosis. Vertical transmission to seeds occurs at high rates regardless of stroma production.
Alkaloid Production
Epichloë elymi is known to produce the insect-feeding deterrent peramine. It has not been shown to produce ergot alkaloids, lolines, or indole-diterpenes.
Hybridization
Asexual hybrid endophytes found in Elymus canadensis have been identified as interspecific hybrids between E. elymi and Epichloë amarillans, containing ancestral genomes from both species. These hybrids are unable to form stromata on host plants.
References
- Schardl, C.L.; Leuchtmann, A. (1999). "Three new species of Epichloë symbiotic with North American grasses". Mycologia. 91 (1): 95–107. doi:10.1080/00275514.1999.12060996.
- Tintjer, T.; Leuchtmann, A.; Clay, K. (2008). "Variation in horizontal and vertical transmission of the endophyte Epichloë elymi infecting the grass Elymus hystrix". New Phytologist. doi:10.1111/j.1469-8137.2008.02441.x.
- Tintjer, T.; Rudgers, J.A. (2006). "Grass–herbivore interactions altered by strains of a native endophyte". New Phytologist. 170 (3): 513–521. doi:10.1111/j.1469-8137.2006.01720.x.
- Burr, K.; Mittal, S.; Hopkins, A.; Young, C.A. (2007). "Characterisation of fungal endophytes present in Elymus canadensis (Canada wildrye)". NZGA Research and Practice Series. doi:10.33584/rps.13.2006.3126.
- NCBI Taxonomy Browser: Epichloe elymi (Taxonomy ID: 55200).
