Festuca rubra is a perenníal grass which is naturally infected by the endophytic fungus Epichloe festucae. lnfected grass plants produce several alkaloids toxic to herbivores. In natural grasslands from western Spain, where cattle are maintained under extensive management, 70 % of the Festuca rubra plantS were found to be infected by Epichloe festucae. We determined the concentration of the alkaloids ergovaline (toxic to livestock) and peramine (an insect feeding deterrent) in endophyte infected plants from two wíld populations of Festuca rubra. Both alkaloids were detected in plants of both popuJations. The percentage of plants containing ergovaline ranged from 17-50 % and that containing peramine from 3380 % at each popuiation studied. A low percentage of the plants (10-17 %) were found to produce both alkaloids. In one of the populations 70 % of the analysed plants produced peramine but not ergovaline.

Resumen del trabajo presentado en la 20th General Meeting of the European Grassland Federation, celebrada en Luzern (Suiza), del 21 al 24 de junio de 2004