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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Toxicology & Mycotoxin Research » Research » Publications at this Location » Publication #321714

Title: Analysis of the mycotoxigenic fungi associated with southeastern U.S. winegrapes reveals a large population of Fusarium fujikuroi isolates producing high levels of fumonisins

item BOLTON, STEPHANIE - University Of Georgia
item BRANNEN, PHILLIP - University Of Georgia
item Glenn, Anthony - Tony

Submitted to: European Seminar in Fusarium Mycotoxins Taxonomy and Pathogenicity
Publication Type: Abstract Only
Publication Acceptance Date: 3/19/2015
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Mycotoxins pose a serious challenge to a consistently safe food supply worldwide, and their threat is only expected to worsen with our changing climate. Species of Fusarium produce one or more of several mycotoxins, including tricothecenes, zearalenone, and fumonisins, which have been associated with human and animal diseases around the globe. Fumonisins mainly occur in cereal crops but recently fumonisin B2 was discovered in wine. To elucidate the mycotoxin risk in American wine, samples of grapes from nine vineyards in the southeast were collected during harvest 2013, following a growing season with high humidity and rainfall. Grape varieties sampled included Cabernet Sauvignon, Cabernet franc, Malbec, Merlot, Norton, Petit Verdot, Pinot noir, Sangiovese, Tannat, and Touriga Nacional. Potentially mycotoxigenic fungi were isolated from grape samples using dichloran rose bengal chloramphenicol (DRBC) and 2-benzoxazolinone (BOA) selective media. Fusarium isolates were recovered from the grape clusters and identified to species by comparison of translation elongation factor 1-alpha gene sequences to verified strains in the Fusarium MLST, Fusarium-ID, and NCBI databases. Fusarium fujikuroi was the most abundant species (239 isolates), followed by F. proliferatum (52), F. incarnatum-equiseti (14), F. oxysporum (7), F. concentricum (1), and F. solani (1). An in vitro fumonisin production assay with rice as the growth medium was used to quantify fumonisin production for representative isolates using LC-MS/MS. Surprisingly, most F. fujikuroi isolates produced fumonisins B1, B2, and B3 at levels comparable to the F. proliferatum isolates and to the positive control, F. verticillioides. Such capacity for fumonisin production refutes the generally accepted notion that F. fujikuroi produces undetectable or low levels of fumonisins and provides evidence to reconsider this species as a threat to crops of economic significance.