Validation of SNP Markers for High Oleic Acid Trait in Valencia Mapping Population in Peanut.

High oleic acid trait in peanut is desirable due to many beneficial effects on human health and its 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). Two Single Nucleotide Polymorphism markers namely S-2584095 and I-71331 were earlier reported to be associated with high oleic acid trait/gene/s in peanut. The objective of our study was to validate these two markers in a recombinant inbred lines (RIL) mapping population of Valencia using the parents S-3663 from Bulgaria and NuMex-01, a newly released high oleic Valencia peanut from USA. A total of 180 individuals (Recombinant Inbred Lines [RILS]) from each of F₈ and F₉ generations were screened along with two parents were grown in a 13×14 alpha lattice design with three replications.  Two field experiments were conducted in 2014 and 2015 in Brownfield, Texas under irrigated conditions. The seeds from the harvested plots (F₈ in 2014 and F₉ in 2015) were genotyped by using Light Cycler 480. KASP (Kompetitive Allele Specific PCR) assay to detect the presence of targeted SNPs. Seed yield, 100 seed weight and Oleic to Linoleic acid ratio were recorded in both the years. The markers were assayed for the entire mapping population and oil quality was analyzed by HPLC to confirm the results. Out of 180 families that were tested for high oleic trait using HPLC: 83.89% families showed high oleic content in both 2014 and 2015. Among the two markers tested for the presence of high oleic trait, marker S-2584095 showed 79.4% polymorphism while marker I-71331 detected 86.7% polymorphism with the KASP assay genotyping. There was a significant difference (<0.0001) noticed in 2014, 2015 and combined year effect of the individual plants for yield, 100 seed weight and O/L ratio. The environment-centered scatter plot revealed that most of the individuals had high O/L ratio. The present study validates that use of SNP markers is a reliable breeder ready tool for screening high oleic trait for detection of homozygous and heterozygous individuals from segregating materials in early generations for increasing breeding efficiency in terms of time and resources.