Mapping and Comparison of Quantitative Trait Loci for Oleic Acid Seed Content in Two Segregating Soybean Populations

Soybean [Glycine max (L.) Merr.] produces 29.4% of the world's edible vegetable oil. An important determinant of the nutritional value and the oxidative stability of soybean oil is the oleic acid content. Elevation of the oleate content levels leads to the improvement of soybean oil quality. However, our knowledge of the genetic factors underlying oleate variation in soybean seeds remains incomplete, hampering the use of marker-assisted selection in soybean breeding programs. We used a whole-genome scan approach to identify oleate quantitative trait loci (QTLs) in a soybean population segregating for oleic acid content and a cognate segregating population to confirm oleate QTL. A novel oleate QTL with moderate effects was revealed on linkage group F in the proximity of the simple sequence repeat marker sat_309, which was confirmed in both populations across all environments tested. Furthermore, this study verified the existence of an oleate QTL with moderate effects in the proximity of FAD2-1B isoform on linkage group 1, which interacted epistatically with the oleate QTL on linkage group F. Oleate QTLs with moderate effects were also detected on linkage groups A2 and N only in one of the populations under study. Minor QTLs on linkage groups E, L, All, and D2 confirmed previous mapping studies for oleate content in soybean.