Location: National Peanut Research Laboratory
Project Number: 6044-42000-011-00-D
Project Type: In-House Appropriated
Start Date: Apr 11, 2017
End Date: Apr 10, 2022
1. Evaluate pathogen-host interactions, including enzyme production by host and pathogen during aflatoxin accumulation, and identify potential resistance genes for aflatoxin control. 2. Mine the diploid Arachis germplasm collections in peanut to identify resistance to various pathogens, characterize novel sources of resistance to important fungal pathogens, and introgress genes into cultivated peanuts. 2a. Screen wild peanut germplasm collection to identify useful germplsm for resistance to important fungal pathogens (e.g. Aspergillus, Cercospora, Cercosporidium, and Sclerotinia spp.). 2b. Transfer economically important genetic traits from wild Arachis species to cultivated peanuts. 3. Develop integrated strategies for management of fungus-associated peanut diseases.
Mycotoxins are toxic secondary fungal metabolites. Contamination of crops with mycotoxins, particularly aflatoxins, is an important food safety issue and threatens the competitiveness of United States agriculture in the world market. Aflatoxins are strong carcinogens produced in crops by the fungus Aspergillus (A.) flavus. Contamination of crops with aflatoxins is an important food safety issue. The purpose of this project is to develop effective integrated strategies for controlling mycotoxin accumulation and fungal diseases that cause yield losses in peanut. One strategy for reducing aflatoxins is to prevent Aspergillus from invading crops. To achieve this goal, the first objective will evaluate fungus-plant interactions, gene expression and chemical profiling of host and pathogen during aflatoxin accumulation. Another strategy for aflatoxin reduction is to prevent its formation by the fungus. This strategy is based on data from our recent research showing that selected peanut stilbenoids significantly reduce or completely block aflatoxin biosynthesis in A. flavus. The second objective will explore wild Arachis germplasm collections to identify resistance to A. flavus, determine and characterize novel sources of resistance to important fungal pathogens, including species causing early and late leaf spot and white mold diseases, and introgress genes into cultivated peanuts. New genetic and genomic resources will be developed to identify mechanisms of pre-harvest aflatoxin resistance in selected wild peanut germplasm. Understanding these mechanisms is fundamental to efficiently introgress favorable alleles from wild Arachis species to reduce aflatoxin in elite peanut cultivars. The third objective, which is related to the first and second objectives, is to combine knowledge and methodology obtained from these objectives on the reduction of aflatoxin in peanut. The ultimate goal of this objective is to establish new peanut germplasm with increased resistance to toxigenic A. flavus.