High Oleic Acid Trait in Valencia Peanut Mapping Population: Validation with SNP Markers By Kasp Assay.

In peanut, high oleic acid trait is highly desirable due to its beneficial effects on human health and good market value. A high oleic: linoleic acid ratio (O/L) in peanut seeds is controlled primarily by two recessive genes, ahFAD2A and ahFAD2B (ol₁ and ol₂). Previous studies have reported two Single Nucleotide Polymorphism (SNP) markers namely S-2584095 (SNP1) and I-71331 (SNP2) to be associated with high oleic acid trait/gene/s in peanut. In this study, the objectives were to validate SNPs (SNP1 and SNP2) in the mapping population of S-3663 from Bulgaria x NuMex-01, a newly released high oleic Valencia peanut from USA, by KASP assay; to compare marker data with Gas chromatography; and to field evaluate Recombinant Inbred Line (RIL) population for yield, O/L ratio and 100 seed weight. A RIL population plus two parents were grown in a 13×14 alpha lattice design with three replications representing F₈ and F₉ generations. Two field experiments were conducted in 2014 and 2015 in Brownfield, Texas under irrigated conditions. Advanced populations (F₈ and F₉) were genotyped by using Light Cycler 480. KASP (Kompetitive Allele Specific PCR) assay was used to detect the presence of SNP markers. The marker was assayed for the entire mapping population and oil quality was analyzed by HPLC to confirm the results Using gas chromatography results as standard values, the efficiency of the SNP markers were calculated by comparing KASP results with gas chromatography results. SNP1 showed 68% and 72% individuals as high oleic and; 4 % and 8% individuals as low oleic for 2014 and 2015 respectively in relevance with gas chromatography data. However, SNP2 showed 71% and 66% individuals as high oleic and; 3% and 4% individuals as low oleic for 2014 and 2015 respectively in relevance with gas chromatography data. Environment centred scatter plots for O/L ratio showed that 80% of the entries were high oleic which supported KASP genotyping and gas chromatography data. Results showed that use of SNP1 and SNP2 markers is a reliable breeder ready tool for screening high oleic trait for detection of homozygous and heterozygous individuals from population.