An oleate desaturase and a suppressor loci direct high oleic acid content of sunflower (Helianthus annuus L.) oil in the Pervenets mutant

All the 〚HOAC〛 lines derived from the Pervenets mutant carry a specific RFLP (oleHOS) revealed by an oleate desaturase cDNA used as a probe. The 〚LO〛 (linoleic) genotypes do not carry oleHOS, but another allele: oleLOR. We studied 〚HOAC〛 heredity in two segregating populations. In an F2 population, the 〚HOAC〛 trait co-segregated with oleHOS. In a recombinant inbred line F6 population, all 〚HOAC〛 RI lines carried oleHOS. The RI lines carrying oleHOS were either 〚LO〛 or 〚HOAC〛. The absence of 〚HOAC〛 RI lines with oleLOR eliminated the occurrence of a recombination event between the locus carrying oleHOS and the locus carrying Pervenets allele. The 〚HOAC〛 trait is due to 2 independent loci: the locus carrying oleHOS allele and another locus. One allele at this other locus may suppress the effect of oleHOS allele on the 〚HOAC〛 trait. The existence of this suppressor allele has only been suggested for sunflower.