Association of Alleles for High Stearic Acid with Agronomic Characters of Soybean¹

Abstract

Alleles that control four to sevenfold increases in the content of stearic acid in soybean [Glycine max (L.) Merr.] oil have been obtained by artificial mutagenesis. The objective of this study was to evaluate the association of three alleles for high stearic acid with agronomic and chemical characters of soybean. Three mutant lines, A6 with 282 g kg−1 stearic acid, A9 with 163 g kg−1 stearic acid, and A10 with 146 g kg−1 stearic acid, each with a different allele at a single locus controlling stearic acid content in the seed oil, were crossed to one of three high‐yielding genotypes with stearic acid content of about 40 g kg−1. The F1 plants of each mating were backcrossed without selection to the high‐yielding parent. Pairs of highand low‐stearic‐acid lines were selected from BC1F2‐derived lines segregating for a high‐stearic‐acid allele. The pairs of lines were evaluated in a replicated test at three Iowa locations. There were no significant differences in the average yield of the high‐ and the low‐stearic‐acid lines from the A9 and A10 crosses. In the A6 cross, the low‐stearic‐acid lines had significantly greater seed yield than high‐stearic‐acid lines by an average of 7.7%. For the other characters measured, the maximum differences between the mean performance of high‐ and low‐stearic‐acid lines for any of the three crosses were 2.9 days for time of maturity, 4 cm for plant height, 0.3 units for lodging score, 8 mg seed−1 for seed weight, 13 g kg−1 for seed protein, and 1 g kg−1 for seed oil. The stearic acid contents of the BC1F3‐derived lines generally were less than those of their donor parent, which indicated that modifying genes may influence this character.

Genotyping-by-Sequencing-Based Investigation of the Genetic Architecture Responsible for a ∼Sevenfold Increase in Soybean Seed Stearic Acid

“…A6’s stearic acid phenotype was much lower in the three Missouri environments we studied (23.4 ± 4.4, 20.9 ± 2.9, and 22.3 ± 5.5%) as compared with the original report of 28.1% stearic acid (Hammond and Fehr 1983; Lundeen et al 1987), and this difference may be due to different environmental conditions in Northern Missouri compared to Ames, Iowa during seed fill/maturation. Fatty acid traits are relatively simple from a genetic perspective, and the target of ∼20% stearic acid is almost reached with three QTL from A6 (Figure 3), although we noted relatively large environmental variation (Table 2).…”

“…A6 bears several large genomic deletions, including a large portion of chromosome 14 (∼6,221,000 bp) corresponding to ∼1/8 of the chromosome (Gillman et al 2014). Regrettably, A6 is also extremely agronomically deficient, exhibiting poor germination, low seed yield, reduced seed quality, extreme early maturity (MG 0), and short plant stature when alleles for elevated stearic acid are present (Lundeen et al 1987; Hammond and Fehr 1983). Some of the defects are likely due to one (or more) of the significant genomic deletions (Gillman et al 2014).…”

Influence of Reduced Palmitate Content on Agronomic and Seed Traits of Soybean

“…They concluded that the agronomic performance of reduced linolenate lines is not associated with genetic changes related to mutation for reduced linolenate content. Lundeen et al (1987) reported that an allele controlling elevated stearate content in soybean oil was associated with agronomic performance.…”

Mapping the Fas locus controlling stearic acid content in soybean

“…Another property of these alleles in Arabidopsis is to cause up to a 5-fold reduction in plant size. Interestingly, fas a , fas b , and fas alleles also severely depressed yield in soybean (Lundeen et al 1987;Hartman et al 1997). This decrease in yield may be one of the reasons for the slow progress in the development of acceptable commercial cultivars with higher stearic acid content.…”