A comparison of methods used to determine the oleic/linoleic acid ratio in cultivated peanut (Arachis hypogaea L.).

There is an increasing demand in the peanut industry for high oleic peanuts and also for the incorporation of the high oleate trait into newly released varieties. Early generation screening of breeding lines for high oleic acid content greatly increases the efficiency of developing new peanut varieties. The objective of this study was to compare the accuracy of methods used to classify individual peanut seed as high oleic or not high oleic. Results from capillary electrophoresis (CE), two variations of near-infrared reflectance spectroscopy (NIRS), and real-time polymerase chain reaction (RT-PCR) genotyping, were compared with the traditionally accepted reference standard results from gas chromatography (GC). Three hundred and seventy-four (374) seeds, spanning twenty-three (23) genotypes and all four peanut market-types (runner, Spanish, Valencia and Virginia), were individually tested by each method. Percent accuracy levels for rating individual seed as high oleic (H) ranged from 97.4% (NIRS) to 99.5% (CE). All of the methods examined in this study carry only a minor risk for miss-classification (loss of material) and are suitable for use by peanut breeding programs in early generation breeding line screening.