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ARS Home » Pacific West Area » Maricopa, Arizona » U.S. Arid Land Agricultural Research Center » Pest Management and Biocontrol Research » Research » Research Project #439354

Research Project: Aflatoxin Mitigation in Sudan

Location: Pest Management and Biocontrol Research

Project Number: 2020-42000-023-022-T
Project Type: Trust Fund Cooperative Agreement

Start Date: Oct 1, 2020
End Date: Sep 30, 2022

Objective:
The overall objectives of the proposal are to: 1. Quantify the incidence of aflatoxin in groundnut, maize, sorghum, cottonseed, and sesame value chains. 2. Identify, with farmers, the best atoxigenic strains native to Sudan for biocontrol in groundnut, maize, sorghum, cottonseed, and sesame value chains. 3. Formulate the best atoxigenic strains into a commercial product, and engage in product stewardship and market development. 4. Scale-up biological control as the central component of aflatoxin management by executing an appropriate Aflasafe commercialization process. 5. Enhance the technical capacity of national partners (including a graduate student pursuing Doctoral studies, and another pursuing Master of Science studies), extension services, farmers, and other participants in the groundnut, maize, sorghum, cottonseed, and sesame value chains for incorporating biocontrol as a component of integrated aflatoxin management. The USDA-ARS will contribute primarily to Objective 2: Identify, with farmers, the best atoxigenic strains native to Sudan for biocontrol in groundnut, maize, sorghum, cottonseed, and sesame value chains.

Approach:
The USDA-ARS Aflatoxin Biocontrol lab will contribute to Objective 2 above using the following approach: • At least 5,000 isolates of Aspergillus section Flavi will be obtained from groundnut, maize, sorghum, cottonseed, and sesame grains using microbiological methods. • Approximately 1,000 atoxigenic strains of A. flavus will be selected (~250 strains from each crop) after characterizing all the 5,000 isolates. Characterization will include monitoring genetic defects in the aflatoxin biosynthesis gene cluster and evaluation of toxin-production abilities in maize fermentations. • Diversity among atoxigenic strains will be examined using simple sequence repeats (SSR) genotyping and portions of aflatoxin biosynthetic genes will be sequenced. • Atoxigenic strains belonging to genotypes widely distributed across Sudan, with good sporulation rates, and with superior ability to reduce crop aflatoxin content will be considered as potential biocontrol agents. • Twelve candidate atoxigenic A. flavus strains identified and tested in field conditions to assess their abilities to move from soil to grains during the growing season, survival during off-season and ability to reduce aflatoxin contamination by > 80%. • From the 12 candidate strains, the four most effective strains will be selected to constitute the biocontrol product for farmer field testing. • On-farm field performance of the product will be measured in at least 75 farmer fields (efficiency in moving from soil to grains during the growing season, surviving during off-season, reduction of aflatoxin contamination). These data will be used to demonstrate efficacy of the product while preparing the registration dossier.