Location: National Peanut Research Laboratory
Project Number: 6044-21220-001-000-D
Project Type: In-House Appropriated
Start Date: Apr 11, 2022
End Date: Apr 10, 2027
Objective:
Objective 1
Identify and integrate beneficial genes from disease-resistant peanut and wild peanut sources into genetically stable peanut germplasm.
Sub-objective 1A.
Screening for aflatoxin accumulation under laboratory conditions.
Sub-objective 1B.
Identification of disease resistance-associated genes and plant defense mechanisms.
Sub-objective 1C.
Integration of beneficial alleles from wild diploid Arachis species into genetically stable peanut germplasm.
Objective 2
Define specific defensive roles of peanut phytoalexins against Aspergillus spp. and other fungal pathogens and identify their genetic sources as potential resistance to fungal diseases and aflatoxin contamination.
Sub-objective 2A.
Determination of phytoalexin profiles in experimental and field seeds and search for new phytoalexins.
Sub-objective 2B.
Study of potential involvement of pegs in contamination of peanut seeds with aflatoxins.
Approach:
Peanut (Arachis hypogaea) is one of the major food crops in the world. Most of the pathogens that attack peanuts are of fungal origin and are evident etiological factors of over 40 economically important peanut diseases. Aspergillus flavus and A. parasiticus are opportunistic fungal parasites that often invade peanut seeds and produce carcinogenic aflatoxins. Contamination of peanuts with aflatoxins is an important food safety issue and threatens the competitiveness of the United States agriculture in the world market. Aflatoxin monitoring and reprocessing of contaminated peanuts is a passive and costly practice to prevent aflatoxins from entering the food chain. Current peanut cultivars often demonstrate limited resistance to fungal pathogens. Therefore, wild peanut species have received substantial consideration as sources of disease resistance because the narrow genetic base of cultivated peanuts cannot provide the necessary levels of resistance to defend the peanut plant. A prospective approach to reduce disease pressure and aflatoxin contamination is to develop resistant peanut cultivars through introgression of beneficial genes and alleles from wild peanut species into elite cultivars. To achieve this goal, the first objective to identify and integrate beneficial genes from disease-resistant peanut and wild peanut sources into genetically stable peanut germplasm will use this approach. In conjunction with this objective, another promising strategy/second objective is to define specific defensive roles of peanut phytoalexins against Aspergillus spp. and other fungal pathogens and identify their genetic sources as potential resistance to fungal diseases and aflatoxin contamination. Both approaches will generate new knowledge on the mechanisms of peanut resistance to fungal invasion and a faster release of enhanced germplasm and cultivars. The ultimate goal of this project is to reduce peanut disease load and to develop improved germplasm. The beneficiaries of the successful accomplishment of the project goal are breeders and all segments of the peanut industry.
