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United States Department of Agriculture

Agricultural Research Service

Research Project: CONTROL MECHANISMS FOR MYCOTOXIN PREVENTION IN PEANUTS AND THEIR ROTATION CROPS

Location: Peanut Research

Title: Biodiversity of Aspergillus section Flavi in the United States

Author
item Horn, Bruce

Submitted to: Journal of Food Additives & Contaminants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 2, 2007
Publication Date: October 3, 2007
Citation: Horn, B.W. 2007. Biodiversity of Aspergillus section Flavi in the United States. Journal of Food Additives & Contaminants. 24(10):1088-1101.

Interpretive Summary: The molds Aspergillus flavus and A. parasiticus are of great economic importance in the United States due to their production of toxic and carcinogenic aflatoxins in agricultural commodities. Development of control strategies against these molds is dependent upon a basic understanding of their genetic diversity in fields used for agriculture. This review summarizes our current knowledge of diversity in A. flavus and A. parasiticus populations in the United States. The high diversity in populations is a reflection of the versatile activities of these molds in nature, which include colonization of plant debris in soil and parasitism of seeds and grain. Genetic variation within populations may originate from an undiscovered sexual process. Intensive monoculture agriculture not only increases population size but also may increase the potential for aflatoxin production by A. flavus and A. parasiticus.

Technical Abstract: Fungi belonging to Aspergillus section Flavi are of great economic importance in the United States due to the formation of toxic and carcinogenic aflatoxins in agricultural commodities. Development of control strategies against A. flavus and A. parasiticus, the major aflatoxin-producing species, is dependent upon a basic understanding of their diversity in agricultural ecosystems. This review summarizes our current knowledge of species and population diversity in the United States in relation to morphology, mycotoxin production, and genetic characters. The high genetic diversity in populations of aflatoxigenic fungi is a reflection of their versatile habits in nature, which include saprotrophic colonization of plant debris in soil and parasitism of seeds and grain. Genetic variation within populations may originate from a cryptic sexual state. The advent of intensive monoculture agriculture not only increases population size but also may introduce positive selective pressure for aflatoxin production due to its link with pathogenicity in crops. Important goals in population research are to determine how section Flavi diversity in agricultural ecosystems is changing and to measure the direction of this evolution.

Last Modified: 8/22/2014
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