Submitted to: Toxin Reviews
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/10/2008
Publication Date: 5/1/2009
Citation: Scully, B.T., Krakowsky, M.D., Ni, X., Wilson, J.P., Lee, R.D., Guo, B.Z. 2009. Preharvest aflatoxin contamination of corn and other grain crops grown on the U.S. southeastern coastal plain. Toxin Reviews. 28(2-3):169-179. Interpretive Summary: Aflatoxin is a food toxin and carcinogen produced by a fungus that attacks corn grain and other grain crops produced during warm growing seasons between 40o North and South latitude. This contamination is a significant problem because warm season grains, such as corn and sorghum are important components of the American diet and a large potion of these crops are designated as feed for animal consumption. The formation of aflatoxin on grain is typically induced by three external factors, including a fungus known as Aspergillus that causes ear rot, which subsequently produces aflatoxin, insects that attack the developing ear and disperse the fungus, along with drought conditions that favor and exacerbate the formation of this toxin. These three factors can be managed agronomically in the field, but can also be avoided through the development of new corn hybrids that are resistant to the ear rot fungus, ear feeding insects, and drought during the growing season. This review summarizes the progress of an interdisciplinary and multifaceted approach to eliminate preharvest aflatoxin contamination in warm season grain crops grown on the U.S. southeastern coastal plain, where aflatoxin is a recurrent problem.
Technical Abstract: Preharvest aflatoxin contamination of grain grown on the U.S. southeastern Coast Plain is provoked and aggravated by both biotic and abiotic stress factors that influence infection by Asperigillus flavus, Link ex Fr. A. flavus is the primary toxigenic fungus of grain in the region, and the hot and humid weather patterns along with suboptimal summer rainfall favor the development of this organism. An array of arthropod species also contribute to the dispersal of this fungus as they attack and feed on the developing grain. Research on corn grown on the Coastal Plain has the expressed goal of reducing, and perhaps eliminating aflatoxin contamination, using classical crop improvement methods to deploy host plant resistance into “southern adapted” corn germplasm. This research is complimented and enhanced by molecular techniques that have proven invaluable in the identification and development of superior germplasm. It also emphasizes the need to fully understand the biological interactions between fungus, arthropods, crops and the environmental conditions that govern the aflatoxin contamination. Alternative cropping systems that avoid contamination are also integrated into this summary of this research progress.