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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Food and Feed Safety Research » Research » Research Project #420817

Research Project: Developing Resistance to Aflatoxin through Seed-Based Technologies

Location: Food and Feed Safety Research

Project Number: 6054-42000-021-00-D
Project Type: In-House Appropriated

Start Date: Dec 28, 2010
End Date: Dec 27, 2015

1. Develop and implement marker-assisted corn breeding strategy. Identify and characterize novel markers associated with aflatoxin-resistance, e.g., resistance-associated proteins (RAPs), in developing and mature kernels through proteomic and genomic comparisons of resistant and susceptible corn genotypes. 2. Identify new sources of corn germplasm and develop new germplasm resistant to fungal infection and aflatoxin contamination with national and international collaboration, using laboratory and field inoculations of corn kernels with tester fungi designed for rapid resistance screening. 3. Evaluate the contribution of novel RAP genes from corn (see Objective 1) for resistance to A. flavus growth and aflatoxin production and use these genes or others to develop transgenic cotton with enhanced resistance to aflatoxin contamination under greenhouse and field conditions. Identify and transfer resistant varieties to cooperating plant breeders for development of varieties for commercial application. 4. Develop rapid, non-destructive hyperspectral imaging methodology to: a) measure fungal growth and aflatoxin contamination in corn as a tool for use in enhancement of Homeland Security, and b) measure spectral signatures associated with traits for resistance to fungal infection and aflatoxin contamination in corn kernels.

Resistance to aflatoxin contamination will be enhanced in corn and cottonseed through marker assisted breeding and genetic engineering, respectively. In order to accomplish these goals, complex natural resistance mechanisms in corn kernels will be elucidated in resistant corn inbreds through identification of resistance associated proteins using proteomics and other resistance associated compounds through chemical analysis. Understanding the molecular basis of seed based resistances will lead to identification of biochemical factors correlated with resistance for use in marker assisted breeding and/or when pertinent resistance genes are identified and cloned, for use in enhancement of resistance in crops through genetic engineering. This strategy is especially pertinent to cottonseed, which does not possess practical levels of natural resistance to aflatoxin producing fungi in its germplasm base. Another goal is to assess resistance related biochemical products for their stability of expression in native and transgenic crops under environmental conditions (e.g. drought) known to be conducive to aflatoxin contamination. Also as a part of this project, rapid, non destructive detection methodology based upon hyperspectral imaging will be developed to measure fungal growth and aflatoxin in corn kernels and spectral signatures associated with traits for resistance to fungal infection and aflatoxin contamination in corn kernels, and also to measure physical and biochemical attributes in kernels potentially useful in resistance marker selection.