Physical and chemical parameters,Fusarium verticillioides growth and fumonisin production in kernels of nine maize genotypes

Fusarium verticilloides synthesizes fumonisins (FBs) in the field and during faulty storage of maize. FBs are worrisome because of their toxicological effects. Nine maize genotypes differing in physical grain properties, phytochemical profiles, and chemical compositions were evaluated. Kernels were tempered to 18% moisture and purposely contaminated with F. verticilloides to assess differences in mold growth and FBs. The genotype significantly influenced counts with mean values ranging from 12.9 CFU/mLx10⁴ for the highly susceptible Blue Don Goyo to only 1.0 CFU/mLx10⁴ for the Pob84C3 genotype. The concentrations of FBs in these two genotypes were 6.85 and 0.3 ppm, respectively. Popcorn kernels showed a relatively high level of Fusarium counts (7.0 CFU/mLx10⁴) but low concentrations of FBs (1.4 ppm). The large-sized Cacahuacintle and Don Goyo kernels, which had the lowest test weights and highest 1000 kernel weight (TKW) showed the highest occurrence of CFU likely due to their low proportion of pericarp, bound phenolics (coumaric), diferulic acids and bound antioxidants. Correlations indicated that mold counts did not correlate (r² = 0.6, P = 0.08) with FBs. However, grain thickness, hardness, TKW and bound phenolics were related to Fusarium counts. This research demonstrated that contrasting maize genotypes showed different susceptibilities to Fusarium growth and FBs contamination.