Seed oleic/linoleic; Seed oleic acid to linoleic acid ratio QTL_oil; TO:0000491; Fat and essential oil composition related trait; OLratio, Oleic acid to Linoleic acid ratio.

Approximately 50% of peanut seed dry weight is oil of which oleic acid and linoleic acid account for 80% of the total fatty acid. Normal O:L cultivars such as Tifguard have an O:L ratio of 1.0 to 4.0 whereas the ratio can reach as high as 30 to 40 in high O:L cultivars. The high O:L trait is desired by the peanut industry because it confers high oxidative stability to the oil. The reported health benefits of dietary monounsaturated fatty acids, such as lowering of blood low-density lipoprotein levels in postmenopausal hypercholesterolemic women, also makes the conversion of current elite cultivars to high O:L attractive. Delta-12-desaturase (oleoyl-PC desaturase), which catalyzes the addition of a second double bond into oleic acid to make linoleic acid, is the key enzyme regulating the O:L ratio in peanut (Ray et al., 1993). Spontaneous recessive mutants for this enzyme, identified and double mutants have high O:L. Expression of two homeologous genes encoding this enzyme, ahFAD2A and ahFAD2B, must be repressed to achieve high O:L in peanut. ol1 and ol2, have been identified and double mutants have high O:L. Expression of two homeologous genes encoding this enzyme, ahFAD2A and ahFAD2B, must be repressed to achieve high O:L in peanut.
*Extracted from the primary citation