Fumonisin Levels and Fusarium Species in Maize in Isabela Province, Philippines

Abstract

The extensive and intensive cultivation of maize in Isabela Province, Philippines, could have fumonisin risk in maize kernels. Thus, the study aimed to determine the occurrence of fumonisin and toxigenic Fusarium species in maize varieties. Samples collected from six municipalities during the 2019 dry season harvesting. Fumonisin levels were quantified using enzyme-linked immunosorbent assays (ELISA), while identification of Fusarium species was through cultural and molecular methods. The results show that fumonisin was detected in 27.72% hybrid (Bt) maize samples; 72.27% samples were less than the limit of detection (LOD), 12.87% with 200-500 µg/kg, 8.91% with 501-1000 µg/kg, 2.97% with 1000-1500 µg/kg, and 0.99% with 1500-2000 µg/kg. The highest total fumonisin was detected in 1.98% samples with 2120-2410 µg/kg. All samples were within the acceptable level of total fumonisn based on the Philippine National Standard, code of practice in cereal. Identified Fusarium species consist of 68% Fusarium verticillioides, 28% Fusarium proliferatum, 2% Fusarium oxysporum, and 2% Fusarium kyushuense, the first report of Fusarium species from maize grain and first record in the Philippines. The presence of F. verticillioides and F. proliferatum may indicate the occurrence of fumonisin in maize. Monitoring and survey of maize kernels should be done at the post-harvest stage to prevent and control the threat of fumonisin contamination in food and feed. Further study can be done also for the identified Fusarium species to determine their capability to produce fumonisins in maize kernels.