FUNGAL ENDOPHYTE-INFECTED GRASSES - ALKALOID ACCUMULATION AND APHID RESPONSE

The occurrence of the alkaloids N-formyl and N-acetyl loline, peramine, lolitrem B, and ergovaline and the response of aphids to plants containing these compounds were determined in species and cultivars of Festuca, Lolium, and other grass genera infected with fungal endophytes (Acremonium spp., and Epichloe typhina). Twenty-nine of 34 host-fungus associations produced one or more of the alkaloids, most frequently peramine or ergovaline. Three alkaloids (lolines, peramine, and ergovaline) were found in tall fescue and in perennial ryegrass infected with A. coenophialum, while peramine, lolitrem B, and ergovaline were present in perennial ryegrass and in tall fescue infected with A. coenophialum and A. lolii produced similar patterns of alkaloids regardless of the species or cultivar of grass they infected, isolates of E. typhina produced either no alkaloids or only one or two different alkaloids in the grasses tested. Aphid bioassays indicated that Rhopalosiphum padi and Schizaphis graminum did not survive on grasses containing loline alkaloids and that S. graminum did not survive on peramine-containing grasses. Ergovaline-containing grasses did not affect either aphid.