ARS | Publication request: Production of mycotoxins by members of the Aspergillus section Nigri isolated from peanuts and maize in the United States

Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: August 7, 2010
Publication Date: August 7, 2010
Citation: Palencia, E.R., Bacon, C.W. 2010. Production of mycotoxins by members of the Aspergillus section Nigri isolated from peanuts and maize in the United States. American Phytopathological Society Annual Meeting. August 7-10, 2010. Charlotte, NC. 100(6):S10.

Technical Abstract: Fungi of the Aspergillus section Nigri (black aspergilli) are pathogenic to maize, grapes, onions, garlic, apples, mangoes, and peanuts. Although some black aspergilli are reported as opportunistic pathogens, other species are able to colonize maize seedlings as symptomless endophytes, which under stress, can develop symptoms of seedling blight or later on symptoms similar to Fusarium ear rot disease. The main concern for crops infected by black aspergilli is the production of toxic secondary metabolites. Ochratoxin A, the fumonisins, and penicillic acid are examples of these metabolites that are carcinogenic to animals and are thereby classified as mycotoxins. The aim of this research was to screen 60 field black Aspergillus strains, isolated as asymptomatic endophytes from peanut and maize, for production of these mycotoxins. HPLC-MS/MS analysis detected the production of ochratoxin A, fumonisin B1, and penicillic acid when strains were cultured on maize, wheat, and rye seeds. Our results indicated that the most dominant species isolated was A. niger var. niger, and less than 20% of the field isolates were able to produce ochratoxin A, while less than 10% produced fumonisins B1. Pencillic acid was produced in high amounts (> 10 ppm) by these isolates, which is the first report for the production of this mycotoxin by members of the Nigri section. The fumonisins and penicillic acid are also phytotoxic and might play roles in diseases of peanuts and maize.