REACTION OF TALL FESCUE INFECTED AND NONINFECTED BY ACREMONIUM-COENOPHIALUM TO PUCCINIA-GRAMINIS SUBSP GRAMINICOLA

Seedlings of the tall fescue cultivar Kentucky 31 infected or not infected by the endophyte Acremonium coenophialum were evaluated for reaction to Puccinia graminis subsp. graminicola in the greenhouse. Seedlings (11 wk old) were rated for rust infection type (0-4 scale) 2 wk after inoculation with urediniospores. Seedlings rated 0 or 1 were considered resistant and those rated > 1, susceptible; 27% of the infected and 19% of the noninfected seedlings were resistant. In a second experiment, 14 seedlings (10 wk old) each of 20 tall fescue cultivars were inoculated and rated; 12 were infected by endophyte and eight were not. Among the infected cultivars, 7% of the seedlings were rated infection type 0, 2% type 1, 7% type 2, 21% type 3, and 63% type 4. Among the noninfected cultivars, 7% of the seedlings were rated infection type 0, 1% type 1, 4% type 2, 17% type 3, and 71% type 4. Based on these observations, the presence of A. coenophialum in seedlings did not influence infection type of P. g. graminicola.