|A Fusarium fujikuroi population isolated from grapes reveals the need to re-evaluate the species' fumonisin production potential|
S. L. BOLTON (1), P. M. Brannen (1), A. E. Glenn (2). (1) Univ of Georgia, Athens, GA, U.S.A.; (2) USDA - ARS -TMRU, Athens, GA, U.S.A.
Mycotoxins pose a documented threat to crops worldwide, making plant pathology and food science collaboration necessary for the safety and growth of our food supply. The genus <i>Fusarium</i> produces several mycotoxins, including fumonisins, associated with serious diseases of humans and animals. <i>F. verticillioides</i> and <i>F. proliferatum</i> are recognized as the main fumonisin producers in economically significant crops. To date, most <i>F. fujikuroi</i> strains tested in-vitro produce undetectable/low amounts of fumonisins. In 2013, a large population of <i>Fusarium</i> spp. was recovered from southeastern U.S. winegrapes, representing eight vineyards and ten grape varieties. This population includes 239 isolates of <i>F. fujikuroi</i> and 52 isolates of <i>F. proliferatum</i>, as identified via PCR amplification of the translation elongation factor 1-alpha gene followed by sequence comparisons to verified strains in GenBank. A phylogenetic analysis revealed genetic diversity within populations of both species, and an in-vitro mycotoxin assay quantified fumonisin B1-B3 production for representative isolates using HPLC-MS/MS. In contrast to previously published work, these <i>F. fujikuroi</i> isolates produced high levels of fumonisins comparable to <i>F. verticillioides</i> and <i>F. proliferatum</i>. Published strains of all three species were included in the assay for comparison. This research shows that <i>F. fujikuroi</i> needs to be reconsidered as both a fumonisin producer of concern and as a threat to food safety.