Inheritance of Mid-Oleic Fatty Acid Ratio Seed Trait in Peanut

In the past, the term “mid-oleic” was used for peanut (Arachis hypogaea L.) seed with an oleic (O) to linoleic (L) fatty acid ratio ranging between 3 to 5:1. The objective of this genetic study was to determine the inheritance of the mid-oleic trait. Crosses were made between two mid-oleic genotypes, ‘NC 7’ and GA 132504 x ‘Tifguard’, a normal-oleic cultivar and the high-oleic cultivar ‘TifNV-High O/L’. In the cross combinations between NC 7 x Tifguard and GA 132504 x Tifguard, the average F1 plant (F2 seed) O/L ratio was 3.3:1 and 2.5:1, respectively. No F2 plants (F3 seed) segregation was found for the high-oleic trait. However in the cross combinations between NC 7 and GA 132504 x TifNV-High O/L, the average F1 plant (F2 seed) O/L ratio was 8.1:1 and 9.0:1, respectively. Likewise, the F2 plant (F3 seed) segregation from both crosses did show an acceptable fit for a 3 normal (mid)-oleic to 1 high-oleic expected genetic ratio. These results strongly supports the similarity between mid-oleic and normal-oleic genotypes which both differ by only one of the two recessive alleles (ol1 and ol2) controlling the high-oleic trait in peanut.