Diversity of foliar endophytes in a dioecious wild grass and their interaction with the systemic Epichloë

Abstract

This study compares the culturable fungal endophytic community inhabiting leaves of Epichloë-infected (E+) and Epichloë-free (E-) plants of Poa bonariensis. Plants were collected from a wild population (dioecious species) where E+ and E- plants co-exist. Fungal endophytes were isolated and then morphology and ribosomal DNA internal transcribed spacer sequences were used for the identification of isolates. In total 24 different taxa of non-Epichloë (NE) endophytes were identified. No significant differences were found in richness and diversity indexes of NE-endophytes between E+ and E- plants, or between pistillate (P) and staminate (S) plants. When we analyzed these effects based on the count of the most abundant genera, Alternaria and Stemphylium infection frequencies decreased in S plants, while in E+ plants, this tendency was observed for Alternaria. Our results suggest that Epichloë and the sex of the host plant may modulate some of the dominant foliar endophytic fungal taxa.