Peanut oil quality is largely determined by its fatty acid composition; therefore, improving the fatty acid profile is a key objective in peanut breeding. Here, we used a recombinant inbred line (RIL) population derived from the cross Jihuatian 1 × PI478819 to map quantitative trait loci (QTLs) for total very long-chain fatty acids (TVLCFAs) and seven individual fatty acid components across two environments, using a combined strategy of BSA-seq and conventional linkage mapping. Based on the major QTLs, we developed kompetitive allele-specific PCR (KASP) markers and validated them in the RIL population. In total, seven QTLs associated with TVLCFAs and the seven fatty acid components were identified. Three QTLs (qA06.1, qA08.1, and qA16.1) were consistently detected in both environments and co-localized for TVLCFAs and behenic acid content, explaining 7.10%-32.85% of the phenotypic variance (PVE). Notably, qA08.1 was also associated with oleic acid, linoleic acid, and palmitic acid contents in both environments, with PVE values of 13.73%-29.33%. The markers Tif2.A06.115805462, Tif2.A08.45741511, and Tif2.A16.148167815, developed for these three major QTLs, effectively distinguished lines with contrasting levels of TVLCFAs, arachidic acid, and behenic acid. In addition, Tif2.A08.45741511 was closely associated with oleic acid, linoleic acid, and palmitic acid contents. Overall, these results provide useful genetic resources for breeding peanuts with low TVLCFAs and high oleic acid content and support accelerated marker-assisted selection for high-quality specialty peanut cultivars.
Zheng et al. (Fri,) studied this question.