Location: National Peanut Research Laboratory
Project Number: 6044-30100-001-000-D
Project Type: In-House Appropriated
Start Date: Jul 22, 2025
End Date: Jul 21, 2030
Objective:
Objective 1: Conduct research to identify peanut with drought tolerance, determine tolerance mechanisms, identify molecular markers or alleles for drought tolerance, and work with breeders to develop peanut varieties that combine drought tolerance with resistance to diseases such as tomato spotted wilt virus and leaf spot. (NP 301, C1, PS1A and PS1B).
Sub-objective 1.a) Evaluate peanut germplasms for drought tolerance, identify potential tolerance mechanisms, and identify molecular markers or alleles for drought tolerance.
Sub-objective 1.b) Develop peanut varieties with drought tolerance, resistance to tomato spotted wilt virus and leaf spot.
Objective 2: Conduct research on host/pathogen interactions in peanut, develop and test novel highthroughput pre-harvest aflatoxin resistance screening methods for accuracy and use them to identify resistance genes and determine gene functions and expression. (NP 301, C1, PS1A)
Sub-objective 2.a) High-throughput seed phenotyping (HTSP) system for pre-harvest aflatoxin screening and evaluation of dsRNA in seeds, in collaboration with NP303
Sub-objective 2.b) Host/pathogen interaction with genetic variants of peanut pathogens, e.g., Aspergillus flavus, Aspergillus niger, Nothopassalora personata, Mycosphaerella arachidis.
Objective 3: Develop molecular genetic tools that can be used to create genetic populations for breeding disease resistant peanut varieties. (NP 301, C1, PS1A and PS1B)
Sub-objective 3.a) Establish an efficient protocol to regenerate peanut plants under in vitro conditions to be used for recovering edited peanut tissues.
Sub-objective 3.b) Establish an efficient gene editing system for the functional study of genes associated with peanut diseases.
Approach:
Drought, aflatoxin, and leaf-spot diseases are the main factors affecting peanut yield and quality, whereas the most desirable strategy to overcome stresses is through improved cultivars. After we released peanut “AU-NPL 17”, higher impact of leaf spot, and increased frequency/duration of droughts, have warranted development of new cultivars. The National Peanut Research Laboratory(NPRL) is equipped with drought-simulation environmental plots that will be used to screen/identify drought tolerant peanut lines, to then study tolerance mechanism(s), and develop molecular markers associated with drought tolerance. We will provide new high-yield cultivars with integrated traits of drought tolerance and disease resistance. The NPRL created a method to identify germplasm with low/no aflatoxin accumulation. Multimillion dollar losses caused by aflatoxins prompted the need to scale-up seed phenotyping to high-throughput (HTSP). This work will support our pre-breeding program NP303-NP301 at the NPRL. Regarding the two recalcitrant peanut-leaf-spot pathogens, we published their first genomes. That information will be used to explore their genetic diversity, host/pathogen interactions, and provide the peanut community with well characterized pathogen isolates to challenge germplasm and thus achieve long-lasting resistance. As for silencing of aflatoxin-biosynthesis gene in Aspergillus, exogenous applications of double strand RNA will continue to be researched. The NPRL has singular expertise in peanut tissue culture, being currently the only one that has obtained peanut seeds in vitro. As specific nucleotide changes associated with beneficial traits are being identified in peanut, those changes could be exerted by gene editing using Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR). The constraint of this technology has been the lack of methodology to regenerate peanut plants from protoplasts, thus, CRISPR has been circumscribed to hairy root tissues in peanut. Our plan is to conceive, design and create a system to obtain stable, edited, whole peanut plants. This system will allow incorporating nucleotide changes linked to resistance to biotic and abiotic stresses and providing fast generation of peanut germplasm for breeding improved cultivars.