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United States Department of Agriculture

Agricultural Research Service

Research Project: ENHANCING CORN WITH RESISTANCE TO AFLATOXIN CONTAMINATION AND INSECT DAMAGE Title: Characterization of a maize association mapping panel for new sources of Aspergillus flavus and aflatoxin accumulation resistance

Authors
item Warburton, Marilyn
item Williams, William
item Windham, Gary
item Murray, Seth -
item Xu, Wenwei -
item Hawkins, Leigh
item Franco, Jorge -

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 9, 2013
Publication Date: November 1, 2013
Citation: Warburton, M.L., Williams, W.P., Windham, G.L., Murray, S., Xu, W., Hawkins, L.K., Franco, J. 2013. Phenotypic and genetic characterization of a maize association mapping panel developed for identification of new sources of resistance to Aspergillus flavus and aflatoxin accumulation. Crop Science. 53:2374-2383.

Interpretive Summary: Maize (Zea mays L.) susceptibility to ear rot and aflatoxin accumulation by Aspergillus flavus (Link:Fr) causes significant economic and human health damage worldwide. Genetic resistance in maize would solve the problem, but no commercial varieties have enough resistance, and there are no populations of maize plants in which to study the trait. We have created a new population containing known and many potential new resistant lines, and here we present the lines, with genetic and phenotypic information including aflatoxin levels, maturity, corn earworm (Helicoverpa zea (Boddie) damage data, and fungal biomass (weight of the fungus in each kernel). In addition to confirming previously reported aflatoxin resistant lines, new resistant lines were identified, which can be used for breeding improved resistant germplasm. The Mexican landrace Tuxpeño is the original source of most of the resistant lines, but a few other novel sources will allow breeders to combine the best sources of resistance into new cultivars. Genetic characterization data presented here will also allow this resource to be used for association mapping of aflatoxin and identification of genes responsible for this important trait.

Technical Abstract: Maize (Zea mays L.) susceptibility to ear rot and aflatoxin accumulation by Aspergillus flavus (Link:Fr) causes significant economic and human health damage worldwide. Although host plant resistance is an ideal solution to the problem, no commercial varieties display sufficient levels of resistance to solve the problem. In addition, because of the lack of resistant maize germplasm in general, no currently available association mapping panels contain significant variation for the trait. A new association mapping panel containing the vast majority of resistant maize lines at the time of compilation is presented here, along with genetic and phenotypic characterization data. Phenotypic data were collected on testcrossed lines from seven environments with three replications each in which aflatoxin levels, maturity, corn earworm (Helicoverpa zea (Boddie) data, and fungal biomass were measured. In addition to identifying the previously reported aflatoxin resistant lines, new resistant lines are presented here, which may be used for breeding improved resistant germplasm. The Mexican landrace Tuxpeño is the original source of most of the resistant lines, but a few other sources may allow additional novel resistance to be pyramided into future breeding lines. Genetic characterization of kinship, genetic diversity, and substructure analysis presented here allow this resource to be used for association mapping of aflatoxin and identification of factors responsible for this challenging quantitative trait.

Last Modified: 10/30/2014
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