Identification of Quantitative Trait Loci for Oil Content in Soybean Seed

Oil is one of the major chemical constituents that affect the quality of soybean [Glycine max (L.) Merr.] products. Soybean seed with high oil content is a valuable source for cooking oil and biodiesel production. The objective of this study was to identify quantitative trait loci (QTL) for oil content to advance soybean breeding efforts. Two F-2-derived recombinant inbred line (RIL) populations, consisting of 242 and 214 individuals from the cross of R05-638 x R05-1415 (Population 1) and R05-4256 x V97-1346 (Population 2), respectively, were used for QTL mapping. The F-2 plants from the mapping populations were genotyped by simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers. Seeds from F-2:3, F-2:4, and F-2:5 lines were tested for oil content using near infrared transmittance technique based on 13% moisture. Six oil QTL regions located on chromosomes 5, 6, 14, 15, and 20 were identified. Among the QTL identified, a major oil QTL (14-40%) on chromosome 20 linked with eight SNP markers was confirmed across genetic populations, locations, and years; this QTL had negative effect on seed protein content. In Population 2, two novel QTL located on chromosomes 6 and 14 accounting for between 11 and 15% and 8 and 15% of the variation in seed oil content, respectively, were detected. These QTL with linked markers can be used for marker-assisted selection for increased seed oil content in soybean breeding programs.