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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 in Commercial Corn Hybrids Artificially Inoculated with Aspergillus flavus in 2008 and 2009

Authors
item Daves, Chris -
item Windham, Gary
item Williams, William

Submitted to: Mississippi Agricultural and Forestry Experiment Station Technical Bulletin
Publication Type: Experiment Station
Publication Acceptance Date: September 10, 2010
Publication Date: October 1, 2010
Citation: Daves, C., Windham, G.L., Williams, W.P. 2010. Aflatoxin accumulation in commercial corn hybrids artificially inoculated with Aspergillus flavus in 2008 and 2009. Mississippi Agricultural and Forestry Experiment Station Research Report. Vo. 24, No. 9. 6 p.

Interpretive Summary: Aflatoxin is produced by the fungus Aspergillus flavus and is a major problem for corn producers in the southern United States. The most desirable method for controlling aflatoxin contamination in corn is the use of resistant plants. Studies were conducted at two locations (Mississippi State, MS, and Raymond, MS) to compare commercial hybrids for resistance to aflatoxin accumulation. Developing corn ears were inoculated with the fungus Aspergillus flavus during silking stage. Ears were hand harvested approximately 63 days after inoculation and aflatoxin was quantified using the Vicam AflaTest. Aflatoxin contamination was extremely high in 2008 at both locations. Commercial hybrids with the lowest levels of aflatoxin were Terral TV24R83 at Mississippi State and Dyna-Gro DG58P45 at Raymond. In 2009, aflatoxin contamination was much lower compared to the levels observed in 2008. Commercial hybrids with the lowest levels of aflatoxin were Golden Acres 28Z89 at Mississippi State and DEKALB DKC 68-06 at Raymond. The most resistant lines to aflatoxin accumulation were resistant single-cross hybrids made by ARS researchers and included in the studies as controls. Several of these resistant single-cross lines had aflatoxin contamination below the action threshold of 20 ppb. Although none of the commercial hybrids had consistently low levels of aflatoxin accumulation, the corn industry appears to be making progress in developing hybrids with resistance to aflatoxin accumulation. These studies also demonstrate the need for continued efforts in identifying corn genotypes with resistance to aflatoxin accumulation and molecular markers associated with resistance.

Technical Abstract: Commercial corn hybrids were grown at two locations and evaluated for resistance to aflatoxin accumulation. In 2008, 92 commercial corn hybrids and 8 single-cross hybrids were grown at Mississippi State, MS, and 77 commercial corn hybrids were grown at Raymond, MS. In 2009, 35 commercial corn hybrids and 5 single-cross hybrids were grown at both locations. Plants were artificially inoculated 7 days after midsilk (50% of the plants in the plot had silks emerging) with Aspergillus flavus isolate 3357 using the side-needle technique. Ears were harvested ca. 63 days after midsilk and aflatoxin was quantified using the Vicam AflaTest. Aflatoxin contamination was extremely high in 2008 at both locations.Commercial hybrids with the lowest levels of aflatoxin were Terral TV24R83 (77 ppb) at Mississippi State and Dyna-Gro DG58P45 (285 ppb) at Raymond. In 2009, aflatoxin contamination was much lower compared to the levels observed in 2008. Commercial hybrids with the lowest levels of aflatoxin were Golden Acres 28Z89 (45 ppb) at Mississippi State and DEKALB DKC 68-06 (167 ppb) at Raymond. The most resistant lines to aflatoxin accumulation were the resistant single-cross hybrids. Several of these lines had aflatoxin contamination below the action threshold of 20 ppb. Although none of the commercial hybrids had consistently low levels of aflatoxin accumulation, the corn industry appears to be making progress in developing hybrids with resistance to aflatoxin accumulation. These studies also demonstrate the need for continued efforts in identifying corn genotypes with resistance to aflatoxin accumulation and molecular markers associated with resistance.

Last Modified: 9/21/2014
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