Enhancing oleic acid content in two commercially released peanut varieties through marker‐assisted backcross breeding

Two elite varieties of peanut, GPBD 4 and G 2–52, with high productivity, oil content, resistance to late leaf spot (LLS) and rust diseases were improved for oleic acid content using marker‐assisted backcrossing. Since both the recurrent parents already possessed the mutant allele at AhFAD2A, only mutant allele at AhFAD2B was transferred from the donor SunOleic 95R (oleate of 80.6%). Three rounds of backcrossing with foreground selection using allele‐specific PCR and Kompetitive allele‐specific PCR (KASP) assay identified a large number of plants homozygous for the mutant allele at AhFAD2B in BCnF2 generations. Evaluation of the advanced generations could identify six and ten lines with significantly higher oleate than GPBD 4 and G 2–52, respectively. Considering the yield, shelling percentage, oil and oleate content, the most promising lines HOBC2GPS_7 and HOBC2G2S_5 were selected with 112% and 142% oleate recovery over GPBD 4 and G 2–52, respectively. ddRAD‐Sequencing of these superior lines showed background genome recovery of 77.5% and 69.0%, respectively. These advanced breeding lines with high oleate (∼80%), resistance to LLS and rust and high productivity are under further trials for possible release as varieties for commercial cultivation.