The level of oleic acid in peanut seed is one of the most important factors in determining seed quality and is controlled by two pairs of homeologous genes ( FAD2A and FAD2B). The genotypes of eight F8 breeding lines were determined as AABB, aaBB, AAbb, and aabb by real-time polymerase chain reaction and sequencing. Fresh seeds were collected from five seed developmental stages and, after drying, were used for chemical analysis. Our results showed that (1) as seeds developed, seed weight, oil content, and oleic acid level significantly increased, whereas four other fatty acid levels decreased, but protein content and another four fatty acid levels did not significantly change, (2) FAD2A/ FAD2B significantly affected fatty acid profiles but not oil and protein contents, and (3) the data were consistent across 2 years. The variability of seed quality traits revealed here will be useful for peanut breeders, farmers, processers, and consumers.
Keywords: Arachis hypogaea; cultivated peanut; fatty acid desaturase 2 (FAD2) genotype; gas chromatography (GC); nitrogen analyzer (NA); nuclear magnetic resonance (NMR); seed chemical composition; seed developmental stage.