Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: ENHANCING CORN WITH RESISTANCE TO AFLATOXIN CONTAMINATION AND INSECT DAMAGE

Location: Corn Host Plant Resistance Research

Title: Aflatoxin accumulation and kernel infection of maize hybrids inoculated with Aspergillus flavus and A. parasiticus

Authors
item Windham, Gary
item Hawkins, Leigh
item Williams, William

Submitted to: World Mycotoxin Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 30, 2009
Publication Date: February 1, 2010
Citation: Windham, G.L., Hawkins, L.K., Williams, W.P. 2010. Aflatoxin Accumulation and Kernel Infection of Maize Hybrids Inoculated with Aspergillus flavus and Aspergillus parasiticus. World Mycotoxin Journal. 3(1):89-93.

Interpretive Summary: Aflatoxin contamination of corn grain is a major problem for producers in the southern United States. To identify resistant corn lines, researchers must evaluate plants for aflatoxin resistance in the field. Infection by Aspergillus flavus, the fungus that produces aflatoxin, is sporadic from year to year so researchers must apply fungal spores to the test plants. The strain commonly used in field evaluations is strain 3357. It is not known whether combining strain 3357 with other Aspergillus strains would provide more consistently high levels of aflatoxin. We conducted field experiments over a three year period to examine the ability of two A. flavus strains (3357 & 19772), and an A. parasiticus strain (6111), and all combinations of the strains to infect developing corn kernels and induce aflatoxin formation. Strain 3357 alone and in combination with the other two strains generally yielded the highest levels of kernel infection and aflatoxin production. Strain 6111 also produced high levels of kernel infection and aflatoxin contamination. The lowest levels of aflatoxin contamination most years were in ears inoculated with strain 19772. Our studies determined that combining strain 3357 with other Aspergillus strains did not consistently produce higher levels of kernel infection or aflatoxin contamination.

Technical Abstract: Field experiments were conducted over a three year period to examine the ability of two Aspergillus flavus strains (NRRL 3357 and NRRL 19772), and an A. parasiticus strain (NRRL 6111), and all combinations of the strains to infect developing maize kernels and induce aflatoxin formation. Maize hybrids were inoculated with the Aspergillus strains using the side-needle technique at 7 days after midsilk (50% of the plants had silks emerged). Aspergillus kernel infection and aflatoxin contamination was determined at ca. 63 days after midsilk. A. flavus strain 3357 alone and in combination with the other two strains generally yielded the highest levels of kernel infection and aflatoxin contamination in both maize hybrids. A. parasiticus strain 6111 also produced high levels of kernel infection and induced high levels of aflatoxin contamination. A. flavus strain 19772 produced the lowest levels of aflatoxin contamination and kernel infection when used alone. A. flavus strain 3357 is the standard strain used to evaluate maize germplasm for aflatoxin resistance in the southeastern U.S. Our studies determined that combining this strain 3357 with other Aspergillus strains did not consistently produce higher levels of kernel infection or aflatoxin contamination.

Last Modified: 8/21/2014
Footer Content Back to Top of Page