Zearalenone in New Zealand pasture herbage and the mycotoxin-producing potential of Fusarium species from pasture

Abstract Zearalenone, in concentrations of 0.4 — 4.0 mg/kg dry weight of herbage, was found in 10 of 60 pasture samples collected from January to April 1985 at sites near Pukekohe, Wanganui, and Gisborne. It was present most often and in highest concentrations in samples from a Gisborne coastal farm. Zearalenone was produced in culture by some strains of eight of the Fusarium spp. most often recovered from the samples, but most consistently and in greatest amounts by F. crookwellense and F. culmorum. There was no correlation between zearalenone concentrations in the samples and Fusarium numbers, as determined by direct counts of macroconidia and by dilution plating. There was also no correlation between zearalenone concentrations and the in vitro zearalenone-producing potential of the Fusarium spp. recovered. Site-related factors appeared to affect zearalenone concentrations as much as the presence of Fusarium spp. Cytotoxicity of the Fusarium cultures to HEp2 cells in tissue culture, indicative of the pr...