Enhancement of performance in tall fescue by endophyte presence

Abstract

Summary Background and aims: The invasion of exotic plant species can be facilitated by the presence of endophytes. Plants and caryopses of Lolium arundinaceum (tall fescue) are frequently infected by the endophytic fungus Epichloë coenophiala, which is toxic to livestock. This study evaluated the effect of E. coenophiala on vegetative and reproductive growth and caryopsis germination in tall fescue under defoliation, as well as fungal transmission from maternal plants to caryopses. M&M: The experiment was conducted outdoors. Plants from two infection levels (infected and uninfected) were grown individually in pots. During the vegetative stage, shoot biomass was removed at 6 cm height every 230 °C days. Results: All plants survived and reached the reproduction stage. Endophyte presence did not impose a cost on the evaluated traits. The relative growth rate of shoot biomass and the length of primary seminal root were significantly higher in infected than in uninfected plants. Infected plants tended to have higher reproductive effort, caryopsis number, and vegetative biomass per plant than uninfected plants. Defoliation did not disrupt vertical transmission of the endophyte to caryopses. Conclusions: The results suggest that tall fescue plants infected with E. coenophiala may exhibit higher fitness than uninfected plants. These traits are likely to contribute to the successful propagation of tall fescue across different environments in the Pampas region.