Effects of natural hybrid and non-hybrid Epichloë endophytes on the response of Hordelymus europaeus to drought stress
Article first published online: 18 SEP 2013
© 2013 The Authors. New Phytologist © 2013 New Phytologist Trust
Volume 201, Issue 1, pages 242–253, January 2014
How to Cite
Oberhofer, M., Güsewell, S. and Leuchtmann, A. (2014), Effects of natural hybrid and non-hybrid Epichloë endophytes on the response of Hordelymus europaeus to drought stress. New Phytologist, 201: 242–253. doi: 10.1111/nph.12496
- Issue published online: 26 NOV 2013
- Article first published online: 18 SEP 2013
- Manuscript Accepted: 2 AUG 2013
- Manuscript Received: 20 MAR 2013
- Swiss National Science Foundation. Grant Number: 31003A-117729
- drought adaptation;
- hybrid endophyte;
- niche expansion;
- woodland grass
- Interspecific hybrid endophytes of the genus Epichloë (Ascomycota, Clavicipitaceae) are prevalent in wild grass populations, possibly because of their larger gene variation, resulting in increased fitness benefits for host plants; however, the reasons are not yet known. We tested hypotheses regarding niche expansion mediated by hybrid endophytes, population-dependent interactions and local co-adaptation in the woodland grass Hordelymus europaeus, which naturally hosts both hybrid and non-hybrid endophyte taxa.
- Seedlings derived from seeds of four grass populations made endophyte free were re-inoculated with hybrid or non-hybrid endophyte strains, or left endophyte free. Plants were grown in the glasshouse with or without drought treatment.
- Endophyte infection increased plant biomass and tiller production by 10–15% in both treatments. Endophyte types had similar effects on growth, but opposite effects on reproduction: non-hybrid endophytes increased seed production, whereas hybrid endophytes reduced or prevented it completely.
- The results are consistent with the observation that non-hybrid endophytes in H. europaeus prevail at dry sites, but cannot explain the prevalence of hybrid endophytes. Thus, our results do not support the hypothesis of niche expansion of hybrid-infected plants. Moreover, plants inoculated with native relative to foreign endophytes yielded higher infections, but both showed similar growth and survival, suggesting weak co-adaptation.