Severity of Fusarium ear rot and concentration of fumonisin in grain of Argentinian maize hybrids

Fusarium ear rot severity and fumonisin concentration in grain of 16 Argentinian maize hybrids were assessed after inoculation with Fusarium verticillioides. Differences among hybrids for both traits indicate that field contamination with fumonisins might be reduced by sowing the most resistant genotypes currently grown in Argentina. Positive phenotypic (0.790.89) and genotypic (0.850.98) correlations between symptom severity and concentration of fumonisins indicated that genotypic effects for concentration of fumonisins in grain mainly depended on genotypic effects for disease resistance, and that visual ratings of disease severity might be used as a preliminary selection criterion to eliminate hybrids accumulating the highest levels of fumonisins. Since a minor proportion of genotypic variability for concentration of fumonisins in grain did not depend on disease severity, these hybrids might vary in frequency or expression of genes affecting production of fumonisins by F. verticillioides after colonization.