Submitted to: Multicrop Aflatoxin and Fumonisin Elimination and Fungal Genomics Workshop-The Peanut Foundation
Publication Type: Abstract Only
Publication Acceptance Date: 10/24/2008
Publication Date: 4/22/2008
Citation: Accinelli, C., Abbas, H.K., Zablotowicz, R.M., Wilkinson, J.R. 2008. Aspergillus Flavus/Aflatoxin Occurrence and Expression of Aflatoxin Biosynthesis Genes in Soil. Multicrop Aflatoxin and Fumonisin Elimination and Fungal Genomics Workshop-The Peanut Foundation. 54:371-379
Technical Abstract: Mycotoxins, including aflatoxins, fumonisins, cyclopiazonic acid (CPA), and zearalenone, produced by Aspergillus and Fusarium species when present in grain can cause serious health problems in livestock and humans. Little is known about the occurrence of these toxins in corn plant debris post-harvest. The objective of this study was to determine the overwintering mycotoxin levels in corn stover, cobs, and cobs containing grain on the soil surface three to six months after harvest. Isolines of the hybrid Pioneer brands 34B24(Bt) or 34B23 (non-Bt) were planted in Elizabeth, MS in 2006. Samples were dried, ground and analyzed for aflatoxin, fumonisin, zearalenone, and CPA. At maturity, grain from Bt hybrid contained significantly less total aflatoxin than the conventional hybrid (109 vs 200 ng g-1). In stover residues less than 4 ng g-1 aflatoxin was observed in both hybrids. Higher aflatoxin levels were found in cobs (17 to 111 ng g-1) and cobs containing grain (541 to 774 ng g-1) with significantly greater levels in the non-BT hybrid compared to the BT hybrid (Pr > 0.01). Pooled over hybrids, fumonisin levels averaged 3 'g g-1 in stover, vs 12 'g g-1 in cobs, and 120 'g g-1 in cobs with grain, with no difference between hybrids. The pattern of partitioning of zearalenone in corn residues was different than other mycotoxins in that the lowest concentration was observed in cobs with grain (mean = 0.08 'g g-1 ) compared to cobs (mean = 0.50 'g g-1) or stover (0.67 'g g-1) with no DON or its derivatives (3A-DON, 15ADON, nivalenol) detected in any samples. The presence of high levels of these mycotoxins in corn residues could be detrimental to grazing livestock or wildlife.