Application of marker-assisted selection for ahFAD2A and ahFAD2B genes governing the high-oleic acid trait in South African groundnut cultivars (Arachis hypogaea L.)

Abstract

One of the major shortcomings in cultivated groundnut in South Africa is the short shelf-life of the product due to rancidity of the oil rich seeds. Polyunsaturated fatty acids are more susceptible to oxidation than mono-unsaturated residues. Thus, it would be preferable to adjust the oleic acid: linoleic acid ratio to a more favourable one. The high-oleic acid trait in groundnut was reported to be dependent on two homeologous oleoyl-PC desaturase genes, ahFAD2A and ahFAD2B. Breeding of new cultivars with this characteristic can be time-consuming and expensive when doing fatty acid analysis in every generation for selection of the progeny with the highest oleic acid: linoleic acid ratio. Marker-assisted selection was applied to the local groundnut breeding program with the utilization of real-time polymerase chain reaction (PCR). The inheritance of the high oleic trait was followed in the 4 th backcross progeny and revealed that all combinations of the two genes were found, except the ol 2 ol 2 homologous mutant. The highest oleic acid percentage was found in progeny with all four mutant alleles (ol 1 ol 1 ol 2 ol 2).