Mycotoxins produced by Fusarium spp. in isogenic Bt vs. non-Bt maize hybrids under European corn borer pressure

Stalk and ear rots caused by Fusarium subspecies are often related to mycotoxin accumulation in maize (Zea mays L.) kernels. Various mycotoxicoses in livestock and humans are triggered by the consumption of these toxins. The European corn borer (Ostrinia nubilalis Hübner) reportedly promotes the infection by Fusarium spp. The objectives of our study were to (i) evaluate the concentration of deoxinivalenol (DON), 3-acetyl-deoxynivalenol (3-A-DON), 15-acetyl-deoxynivalenol (15-A-DON), fumonisin (FUM), fusarenon-X (FUS-X), moniliformin (MON), and nivalenol (NIV) in kernels; (ii) determine the level of European corn borer (ECB) resistance; and (iii) investigate the association between the concentration of mycotoxins and ECB resistance. The study used early maturing European Bt (Bacillus thuringiensis) cultivars, their isogenic counterparts, and commercial hybrids. The field experiments were conducted at three locations in Germany. The mycotoxins most prevalent were DON, FUM, and MON. Plots infested by and protected from ECB differed significantly for DON and FUM concentrations. In addition, significant differences were found for concentrations of FUM between isogenic Bt and non-Bt hybrids. The two Bt events - Bt176 and Mon810 - were also significantly different for FUM concentrations. Not all mycotoxins were related to ECB damage. Insect management and, therefore, the use of Bt cultivars may be a short-term solution to minimize toxins in kernels.