XVI International Botanical Congess

We examined occurrence of endophyte infections of 14 grass species in wild populations and 13 species in cultivars in Finland. Mean infection frequensies were lower than past literature has suggested. In wild populations, the highest mean incidences of infected plants were found in Agrostis capillaris, Festuca arundinaceae, F. pratensis and F. rubra, being 15-69 %. No infection were detected in four grass species. However, we detected high variation in infection incidencies (0-100%) among populations, supporting the idea that endophytic fungi provide selective advantage of infected grasses to their conspesifics in some habitats. In cultivars, endophyte infected seeds were detected only in F. pratensis and Lolium perenne, and frequensies were either very high or very low.