|Palencia, Edwin - University Of Georgia|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/20/2011
Publication Date: 2/20/2011
Citation: Palencia, E.R., Bacon, C.W. 2011. Potential production of ochratoxins and fumonisins by members of the Aspergillus section Nigri isolated as endophytes from maize and peanuts. Genetics of Maize Disease Workshop Renaissance. February 20-23,2011. Raleigh North Hills, NC.
Technical Abstract: Members of the Aspergillus section Nigri (black aspergilli), are pathogenic to several plant hosts including maize, peanuts, grapes, onions, garlic, apples, and mangoes. Although some black aspergilli are reported as opportunistic pathogens, we have documented that some species within this section are able to colonize maize seedlings as symptomless endophytes, which under drought stress, may lead to symptoms similar to Fusarium ear rot disease in maize. However, a main concern with black aspergilli plant infection by the black aspergilli is the production of the mycotoxins ochratoxins A (OTA) and B, and fumonisins B1, B2, and B3 (see chemical structures), all of which are toxic to livestock and poultry. The aim of this research was to screen 41 field black Aspergillus isolates obtained as asymptomatic endophytes from peanut and maize kernels, identify the isolates, and determine their ability to produce mycotoxins fumonisin B1 and ochratoxin . The black aspergilli were identified by a molecular barcoding procedure we developed and endophytism of the species or strain was determined by isolation from surface disinfected plant and seed materials. Mycotoxins were analyzed by an HPLC-MS/MS system that was used to confirm the production of ochratoxins A and B, and fumonisins B1, B2 and B3 using maize kernels, as well as wheat and rye seeds as natural substrates. Our results indicated that the most predominant isolated species was A. niger var. niger, and of the strains surveyed approximately 20% of the field isolates were capable of producing ochratoxin A and approximately 10% produced fumonisins B1, and B2.