Seed oleic acid phenotype and FAD2-1 genotype association analysis for population 2. Average oleic acid content of soybean seeds produced in Portageville, MO from the segregating F6 and F7 RILs developed from the cross M23 × PI 283327, population 2. X-axis labels indicate a typical commodity soybean line (Jake), the two RIL parents, and the RILs grouped by FAD2-1A and FAD2-1B genotype. AA = wild-type FAD2-1A alleles, aa = mutant FAD2-1AΔ alleles derived from M23, BB = wild-type FAD2-1B alleles, bb = mutant P137R FAD2-1B alleles derived from PI 283327; brackets surround the number of soybean seed samples represented in the genotype class. Error bars indicate plus and minus one standard deviation from the mean. Oleic acid phenotype data of each genotype class is the mean of oleic acid content as a percentage of the total fatty acid content of the oil of all lines carrying the FAD2-1 genotype, five individual samples for each line, with two exceptions, one for class aaBB, where six lines had ten seed samples and eight lines had five seed samples. Additionally, two separate individual seed samples from the aabb lines were ommitted from the analysis because their genotypes could not be verified. Including these two samples would have led to a mean of 80.8 ± 8.0% oleic acid for the FAD2-1 aabb genotype class. Subsequent sampling of ten additional seeds from these lines produced oleic acid levels with a range of 81.5% to 86.2% oleic acid in the seed oil.