Infection of Tall Fescue Seed in Missouri by the Endophyte Epichloe typhina. F. Rycyk, Jr., Missouri Department of Agriculture, Jefferson City 65102. D. Sharpe, Missouri Department of Agriculture, Jefferson City 65102. Plant Dis. 68:1099. Accepted for publication 29 August 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-1099b.
Epichloe typhina (Fr.) Tul. (=Acremonium coenophialum Morgan- Jones & Cams), the tall fescue (Festuca arundinacea Schreb.) endophyte, has been associated with summer slump toxicity syndrome in cattle grazing infected pastures. In 1983 in Missouri, which produces approximately 70% of the tall fescue seed in the United States, 193 samples, each representing a separate seed-production field, were drawn from trucks delivering seed to seed houses. One hundred seeds from each sample were microscopically examined after partial digestion in nitric acid and staining with aniline blue. The highly convoluted, small- diameter mycelium characteristic of E. typhinawas observed in at least some of the seed from all samples, and 91% of the seed lots. examined had 50% or more infection. The identity of E. typhina infection was confirmed by enzyme-linked immunosorbent assay (ELISA) at Auburn University.