Identification of a mutant from Arachis veigae with enhanced seed oleic and very long-chain fatty acid content

High oleate is an important seed quality trait frequently incorporated in peanut varieties. Crop wild relatives (CWR) are potentially useful genetic resources for cultivar improvement through genetic introgression; but for wild peanut species, many chemical or nutritional traits are not well characterized. A mutant from Arachis veigae S. H. Santana & Valls (2n = 2x = 20), with increased oleic and very long chain (C ≥ 22) fatty acid content was identified from screening 209 accessions of 45 species using gas chromatography (GC). The A. veigae (formerly A. sylvestris) accession, VVeSv 8373 (PI 688970) contained 55.5% oleic acid in seeds, significantly higher than the average (18.3%) of other accessions within the same species and also significantly higher than the average (37.0%) of all wild peanut accessions evaluated. A C37T substitution was identified by sequencing the coding region of FAD2H, resulting in the nonsense mutation of Q13* (a premature stop codon). This functional mutation may significantly reduce the fatty acid desaturase (FAD) activity and result in the enhanced oleate level. Arachis veigae also contained a high percentage of very long-chain (C ≥ 22) fatty acids, and their variation identified in this study is also discussed and compared with other species. The mutant with such an altered fatty acid composition may be useful for potentially improving seed or food nutrition quality.