Genetic Relationships between Loci Controlling the High Stearic and the High Oleic Acid Traits in Sunflower
- Bego n ˜ a Pérez-Vicha,
- Rafael Garcésb and
- Jose Mar ı ´ a Fernández-Mart ı ´ nez *a
Sunflower (Helianthus annuus L.) lines with seed oils containing either high oleic (C18:1) or high stearic (C18:0) acid have been obtained through induced mutagenesis. The combination of the seed oil phenotypes of these lines would result in a novel oil quality of great value for the food industry. The objectives of this study were (i) to determine the genetic relationships between the high C18:0 and the high C18:1 traits, and (ii) to combine both characters. The sunflower lines HAOL-9 (high C18:1), carrying the high C18:1 Ol alleles, and CAS-3 (high C18:0), with the high C18:0 alleles es1 and es2, were reciprocally crossed. The fatty acid content of the F1, F2, BC1F1 to both parents, and F3 seeds was analyzed by gas–liquid chromatography (GLC). The segregation patterns for C18:0 (F2 ratio of 15:1) and C18:1 (F2 ratio of 1:3 or 7:9) in the F2 and BC1F1 to both parents fit those previously reported when each fatty acid was studied independently. However, a distortion was observed in their combined segregation, indicating that neither character was independently inherited. Furthermore, the analysis of the F3 generation revealed that F2 half seeds with the highest C18:0 concentration in a high C18:1 background were still heterozygous for either the C18:0 or the C18:1 levels, suggesting a genetic linkage between the alleles Es2 and Ol These alleles determine a lower C18:0 and a higher C18:1 content, respectively. No F2 recombination between them was achieved, resulting in the absence of high C18:0/high C18:1 phenotypes. However, some intermediate C18:0/high C18:1 F2 seeds led to stable F3 seeds with this phenotype (130 g kg−1 C18:0/790 g kg−1 C18:1).Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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