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United States Department of Agriculture

Agricultural Research Service

Title: Aspergillus Colonization and Aflatoxin Contamination in Peanut Genotypes with Resistance to Other Fungal Pathogens.

Authors
item Holbrook, C
item Wilson, David - UNIVERSITY OF GEORGIA
item Matheron, Michael - UNIVERSITY OF ARIZONA
item Anderson, William - STONEVILLE PEDIGREE, MS

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 19, 1997
Publication Date: N/A

Interpretive Summary: Aflatoxin is a toxin produced by fungi of the Aspergillus flavus group. When subjected to heat and drought stress late in the growing season, peanut can be contaminated by aflatoxin. Research is ongoing to develop peanut cultivars with resistance to the fungi that produces aflatoxin. Peanut genotypes that have resistance to other fungi are available. The objective of this study was to determine if these genotypes also have resistance to A. flavus and (or) aflatoxin contamination. Nine peanut genotypes with resistance to leaf spot and (or) white mold were evaluated for two years at Tifton, GA and Yuma, AZ. Plots were subjected to late season heat and drought stress. None of these genotypes exhibited less colonization of shells or kernels by A. flavus group fungi than a standard check when tested in Georgia or Arizona. None of these genotypes showed a reduced level of aflatoxin contamination in comparison to a standard check at either location. These results indicate that the mechanisms of resistance to other fungi operating in these genotypes are not effective in providing resistance to colonization by A. flavus group fungi, or reduced aflatoxin contamination.

Technical Abstract: Preharvest aflatoxin contamination is a serious challenge facing the U.S. peanut (Arachis hypogaea L.) industry. Indirect selection tools would be valuable in the development of peanut cultivars with resistance to aflatoxin contamination. The objective of this study was to determine if resistance to other fungi could be used as an indirect selection tool for resistance to colonization of peanut by Aspergillus flavus group fungi and (or) aflatoxin contamination. Nine peanut genotypes with resistance to late leafspot [Cercosporidium personatum (Berk. and Curt.) Deighton and (or) white mold (Sclerotium rolfsii Sace.) were evaluated for two years at Tifton, GA and Yuma, AZ. Plots were subjected to late seasoon heat and drought stress. None of genotypes exhibited less colonization of shells or kernels by A. flavus group fungi than Florunner when tested in Georgia or Arizona. None of genotypes showed a reduced level of aflatoxin contamination in comparison to Florunner at either location. These result indicate that the mechanisms of resistance to other fungi operating in these genotypes are not effective in providing resistance to colonization by A. flavus group fungi, or reduced aflatoxin contamination. Therefore, resistance to these fungi cannot be used as an indirect selection tool for resistance to aflatoxin contamination.

Last Modified: 7/28/2014
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