Reduced-Linolenate Content Associations with Agronomic and Seed Traits of Soybean

Soybean [Glycine max (L.) Merr.] lines with the fan1(A5) fan1(A5)fan2 fan2 genotype for reduced linolenate content produce an oil with improved oxidative stability. The improved oxidative stability reduces the formation of undesirable flavor compounds in the oil. The objective of this study was to determine if reduced linolenate influences agronomic or seed traits of soybean. The single-cross populations AX11224, AX11227, and AX11240 were developed by crossing each of three high-yielding parents with normal-linolenate content of ≈77 g kg⁻¹ to one of three reduced-linolenate parents with ≈26 g kg⁻¹ linolenate. From each of the populations, 27 F₃-derived normal-linolenate lines and 27 reduced-linolenate lines were evaluated at three locations in Iowa during 1996. The mean seed yields of the reduced-linolenate lines were not significantly different (P > 0.05) from the normal-linolenate lines for AX11224 and AX11227, but the mean yield of the reduced-linolenate lines was significantly lower than the normal-linolenate lines for AX11240. The means of the reduced-linolenate lines were not significantly different from the normal-linolenate lines for maturity, lodging, plant height, and protein content in the three populations. The mean oil, stearate, and linoleate contents of reduced-linolenate lines were significantly greater (P < 0.05) than normal-linolenate lines in all populations. Differences between the means of the reduced- and normal-linolenate lines for seed weight, palmitate content and oleate content were not consistent among the populations. The difference among crosses for the relationship of reduced linolenate with seed yield and other traits indicated that multiple reduced- and normal-linolenate parents should be used in a cultivar development program. Journal Paper No. J-17458 of the Iowa Agric. and Home Econ. Exp. Stn., Ames; Projects no. 2799 and 3107.