Growth Kinetic Parameters and Prediction of Growth and Zearalenone and Deoxynivalenol Production Boundaries by Three Fusarium asiaticum Strains Isolated from Wheat

Abstract

Fusarium species can cause head blight of cereals worldwide. This is accompanied by impacts on yield and contamination of grains with mycotoxins. Regulations, with maximum limits, exist for the relevant Fusarium mycotoxins (e.g., type A and B trichothecenes, zearalenone and fumonisins). There is interest in a better understanding of the effect of key interacting abiotic factors which determine colonization and mycotoxin production in small grain cereals. Thus, this study examined the ecophysiological relationship between temperature and water availability (10–35 °C; water activity, aw, 0.87–0.98) on growth and production of Fusarium mycotoxins (zearelenone, ZEA; deoxynivalenol, DON; 3-acetyl deoxynivalenol, 3-Ac-DON and nivalenol, NIV) by three strains of F. asiaticum, a head blight pathogen isolated from China and becoming important in other global regions. These were carried out on simulated wheat-based matrices that identified the optimum (25 °C/0.98 aw) and marginal boundary conditions for growth (35 °C/0.90 aw) for all three strains. Contrarily, different mycotoxigenic profiles were observed between strains (p < 0.05). Four mycotoxins assessed were produced at 30 °C while cold temperature inhibited the production of NIV and ZEA, which were never detected at