Field Performance of High Oleic Soybeans with Mutant FAD2‐1A and FAD2‐1B Genes in Tennessee

Abstract

Soybean [Glycine max (L.) Merr.] oil with high oleic acid (>75%) has increased oxidative stability and health benefits that are valuable for food, fuel, and industrial products. It has been determined that two naturally occurring mutations in genes FAD2‐1A and FAD2‐1B can combine to produce high oleic soybeans. The objective of this study was to test the effect of these mutant alleles on seed yield and oil and protein concentration. Molecular markers assisted in the creation of a population of 48 BC3F2:4 lines (93.75% expected genome commonality). Each line was classified into one of four genotypic groups where both FAD2‐1A and FAD2‐1B genes were either homozygous wild type or mutant, respectively. Twelve lines for each genotypic group were evaluated in three replications at six locations across Tennessee. There was no seed yield difference between the high oleic genotypic group and the other groups (P < 0.05). On the other hand, there were differences in fatty acid profiles and oil and protein concentrations. In combination, the mutant FAD2‐1A and FAD2‐1B alleles produced a mean of 803.1 g kg−1 oleic acid. This is, on average, approximately 500 g kg−1 more oleic acid compared to soybean lines with only one mutant FAD2‐1 allele. The high oleic double mutant group had more total oil (228.0 g kg−1) and protein (401.0 g kg−1) compared to all other genotypic groups (P < 0.05). Overall, this specific combination of mutant FAD2‐1A and FAD2‐1B alleles appears to generate conventional high oleic soybeans without a yield drag.

Agronomic performance of high oleic, low linolenic soybean in Tennessee

“…The mean yield of the quadruple mutant group was 3973 kg ha −1 ranking third out of seven groups tested with a range of 3657 kg ha −1 to 4234 kg ha −1 . This finding suggests that the HO or LL genotype does not impact yield, which is in agreement with previous studies (Cherrak et al, 2003; Darr et al, 2020; Reinprecht et al, 2007). In the HO genotype, the lack of yield drag is likely due to the point mutation at PI 603452 and PI 283327, which would have little to no effect on genes involved in yield that may be closely linked.…”

“…Previous studies have found that soybean plants containing both mutant genotypes FAD2‐1A and FAD2‐1B are necessary to achieve oleic >750 g kg −1 (Darr et al, 2020). As predicted, fatty acid analysis indicated that oleic acid was significantly elevated in all four test groups compared to the checks and parental line Ellis (Table 2).…”

“…Retaining both FAD2‐1A and FAD2‐1B mutant alleles has been established as necessary for target oleic FA (18:1) > 750 g kg −1 (Darr et al, 2020). Therefore, we maintained this mutation in both FAD2‐1A and FAD2‐1B , represented by aabb.…”

“…Pham et al (2012) found that high oleic (HO) lines that contain mutations in both the FAD2‐1A and FAD2‐1B genes, when crossed with low linolenic (LL) soybean lines containing FAD3A and FAD3C mutant alleles, produced progeny with reduced linolenic acid in the soybean oil. The additive effect of the mutated alleles FAD2‐1A and FAD2‐1B is greater than the individual allele affect, with mutation of FAD2‐1A contributing the greatest concentration of oleic acid (Darr et al, 2020; Ruddle et al, 2014).…”

Current Status of High Oleic Seed Oils in Food Processing

“…Resulting lines were classified into one of four genotypic groups where both FAD2‐1A and FAD2‐1B genes were either homozygous wild type or mutant, respectively, and were evaluated at six locations across Tennessee. The specific combination of homozygous mutant alleles FAD2‐1A and FAD2‐1B allows reaching an oleic acid content of around 80% and without penalties in agronomic performance, emerging as a feasible strategy to develop HO soybeans (Darr et al, 2020).…”