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ARS Home » Southeast Area » Tifton, Georgia » Crop Genetics and Breeding Research » Research » Research Project #434346

Research Project: Development of High-Yielding, High-Oleic Peanut Cultivars or Germplasm with Tolerance to Biotic and Abiotic Stresses

Location: Crop Genetics and Breeding Research

2020 Annual Report

Objective 1: Identify and characterize genes/Quantitative Trait Locus (QTLs) controlling resistance to major diseases (leaf spot, white mold, rhizoctonia limb rot, and nematodes) and drought stress, and use the information in marker-assisted breeding to develop improved high oleic (oleic/linoleic fatty acid ratio) peanut cultivars or germplasm with tolerance to biotic and abiotic stresses. Sub-objective 1.A.: Conduct phenotypic evaluations of recombinant inbred line (RIL) populations to aid in the identification and characterization of genes/QTLs controlling resistance/tolerance to biotic and abiotic stresses. Sub-objective 1.B.: Develop improved high oleic peanut cultivars or germplasm with resistance to nematodes and improved resistance to leaf spot. Sub-objective 1.C.: Develop high oleic peanut germplasm with improved drought tolerance and reduced preharvest aflatoxin contamination (PAC).

1.A. Sixteen structured recombinant inbred line (RIL) populations were developed using parents that were selected to maximize genetic diversity while meeting practical breeding objectives. In-depth phenotyping and genotyping of the populations will be conducted to identify genetic markers that can be used in peanut cultivar development. 1.B. Breeding populations will be developed by hybridizing cultivars with high oleic acid with high yielding breeding lines with resistance to the peanut root-knot nematode and/or resistance to leaf spot. Marker assisted selection will be utilized to select early generation progeny that are homozygous for the desired characteristics (high oleic, nematode resistance, and/or leaf spot resistance). Selections in later generations will focus on field resistance to tomato spotted wilt virus, high yield, and other agronomic characteristics. 1.C. Breeding populations will be developed by hybridizing high-yielding, high-oleic cultivars with sources of resistance to preharvest aflatoxin contamination and sources of resistance to drought. These populations will be evaluated under field conditions with drought and heat stress imposed by covering the entire test area with a mobile greenhouse. Aflatoxin contamination of the subsequent yield will be determined using the immunoaffinity column fluorometer method. Progeny will be selected based on relatively low aflatoxin and/or relatively high pod yields.

Progress Report
Crosses were made to combine resistance to biotic and abiotic stresses with high yield, good grade, and high oleic fatty acid content. Populations were advanced to a more inbred state when marker assisted selection (MAS) was used by ARS researchers at Tifton, Georgia, to identify individuals that will breed true for high oleic fatty acid content and/or nematode resistance and/or leaf spot resistance. Progeny from these individuals are then evaluated by ARS researchers at Tifton, Georgia, for resistance to other biotic and/or abiotic stresses, yield, and other agronomic characteristics. One recombinant inbred line (RIL) population (Tifrunner x SSD-6) was phenotyped for resistance to tomato spotted wilt virus (TSWV) using a replicated field study. Quantitative trait loci (QTLs) for resistance to TSWV were identified.

1. Genetic markers for resistance to white mold. Marker assisted selection (MAS) can be used to improve the efficiency and effectiveness of developing new peanut varieties. Genetic markers linked to important traits are needed before MAS can be implemented. White mold is one of the most damaging diseases of peanut with regards to both cost of control and yield loss. ARS researchers at Tifton, Georgia, genotyped and phenotyped a population that was segregating for resistance to stem rot to identify several genetic markers linked to resistance. Six of these were major genetic markers that explained over 10% of observed variation and could be consistently detected in multiple years or locations. Resistance to stem rot is a highly complex and quantitative trait. These genetic markers will allow breeders to use MAS to develop resistant varieties more effectively and efficiently.

2. A new source of root-knot nematode resistance in peanut. The peanut root-knot nematode (RKN) is a very destructive pathogen, to which most peanut varieties are highly susceptible. ARS researchers at Tifton, Georgia, evaluated reaction to RKN in a population derived from crossing peanut with a related wild species, Arachis stenosperma. ARS researchers at Tifton, Georgia, found strong resistance to RKN from the wild species is transferrable and express in cultivated peanut. ARS researchers at Tifton, Georgia, also discovered that the genetic markers for the high level of RKN resistance is in a region rich in known plant defense genes which may be involved in reducing nematode reproduction. These wild-derived genes can be used in breeding programs for transferring new sources of nematode resistance into elite peanut cultivars.

Review Publications
Chu, Y., Chee, P., Isleib, T.G., Holbrook Jr, C.C., Ozias-Akins, P. 2019. Major seed size QTL on chromosomes A05 of peanut (Arachis hypogaea) is conserved in the U.S. minicore germplasm collection. Molecular Breeding. 40(6):1-16.
Luo, Z., Cui, R., Chavarro, C., Tseng, Y., Zhou, H., Peng, Z., Chu, Y., Yang, X., Lopez, Y., Tillman, B., Dufault, N., Brenneman, T., Isleib, T.G., Holbrook Jr, C.C., Ozias-Akins, P., Wang, J. 2020. Mapping quantitative trait loci (QTLs) and estimating the epistasis controlling stem rot resistance in cultivated peanut (Arachis hypogaea). Journal of Theoretical and Applied Genetics. 133:1201-1212.
Ballen-Taborda, C., Chu, Y., Ozias-Akins, P., Timper, P., Holbrook Jr, C.C., Jackson, S., Bertioli, D., Leal-Bertioli, S. 2019. A new source of root-knot nematode resistance from Arachis stenosperma incorporated into allotetraploid peanut (Arachis hypogaea). Scientific Reports. 9:17702.
Gangurde, S.S., Wang, H., Yaduru, S., Pandey, M.K., Fountain, J.C., Chu, Y., Isleib, T.G., Holbrook Jr, C.C., Xavier, A., Culbreath, A., Ozias-Akins, P., Varshney, R.K., Guo, B. 2019. Nested-association mapping (NAM)-based genetic dissection uncovers candidate genes for seed and pod weights in peanut (Arachis hypogaea). Plant Biotechnology Journal.
Holbrook Jr, C.C. 2019. Peanut yield gains over the past fifty years. Peanut Science. 46:73-77.
Koolachart, R., Jogloy, S., Vorasoot, N., Wongkaew, S., Holbrook Jr, C.C., Jongrungklang, N., Kesmala, T., Suriharn, B. 2019. Association of aflatoxin contamination and root traits of peanut genotypes under terminal drought. SABRAO J. of Breeding and Genetics. 51(3):234-251.
Mahakosee, S., Jogloy, S., Vorasoot, N., Theerakulpisut, P., Banterng, P., Kesmala, T., Holbrook Jr, C.C., Kvien, C. 2019. Seasonal variation in canopy size and yield of Rayong 9 cassava genotype under rainfed and irrigated conditions. Agronomy. 9:362.
Chavarro, C., Chu, Y., Holbrook Jr, C.C., Isleib, T.G., Bertioli, D., Hovav, R., Butts, C.L., Lamb, M.C., Sorensen, R.B., Jackson, S.A., Ozias-Akins, P. 2020. Pod and seed trait QTL identification to assist breeding for peanut market preferences. Genes, Genomes, and Genomics. 10:2297-2315.
Zhang, H., Chu, Y., Dang, P.M., Tang, Y., Jiang, T., Clevenger, J.P., Ozias-Akins, P., Holbrook Jr, C.C., Wang, M.L., Campbell, H., Hagan, A., Chen, C. 2020. Identification of QTLs for resistance to leaf spots in cultivated peanut (Arachis hypogaea L.) through GWAS analysis. Theoretical and Applied Genetics. 133:2051-2061.