Aggressiveness to Mature Maize Plants of Fusarium Strains Differing in Ability to Produce Fumonisin

Four strains each of Fusarium moniliforme (syn. Fusarium verticillioides) and Fusarium thapsinum were tested for aggressiveness toward two maize inbred lines grown under greenhouse conditions. All strains induced significantly longer stalk lesions than those observed in the controls. Mean lesion length resulting from inoculation with strains of F. moniliforme was longer than the mean lesion length resulting from inoculation with strains of F. thapsinum. Within each species, however, there was a broad range of lesion lengths observed, and all tested strains of both species probably should be regarded as potential pathogens of maize. No isolate × inbred interaction was detected. Fumonisins may play a role in aggressiveness, but under our conditions, stalk rot and the ability to produce fumonisins in vitro were not correlated.