Agronomic and Seed Traits of 1%‐Linolenate Soybean Genotypes

An oil from soybean [ Glycine max (L.) Merr.] cultivars with <20 g kg −1 linolenate would have a desirable oxidative stability. The objective of our study was to compare the agronomic and seed traits of lines with the genotype fan1 (A5) fan1 (A5) fan2 (A23) fan2 (A23) fan3fan3 , designated as 1%‐linolenate (<20 g kg −1 ) lines, and the genotype fan1 (A5) fan1 (A5) fan2 (A23) fan2 (A23), designated as 2%‐linolenate lines (>20 g kg −1 ). Three backcross populations were developed by crossing three high‐yielding, recurrent parents with ≈25 g kg −1 linolenate to a donor line with ≈13 g kg −1 linolenate. For each population, 27 1%‐ and 27 2%‐linolenate BC 1 F 2:4 lines were evaluated at Ames, Grand Junction, and Hubbard, IA during 1998. The mean seed yields of the 1%‐linolenate lines were 47 kg ha −1 lower in Population 1, 65 kg ha −1 lower in Population 2, and 164 kg ha −1 lower in Population 3 than the 2%‐linolenate lines, but the difference was only significant in Population 3. The maximum mean differences between the 1%‐ and 2%‐linolenate lines in any of the populations for the remaining agronomic and seed traits were 1 d for maturity, 0.1 score for lodging, 2 cm for plant height, 4 mg seed −1 for seed weight, 5 g kg −1 each for protein and oil content, 0.6 g kg −1 for palmitate, 2.2 g kg −1 for stearate, 16.4 g kg −1 for oleate, and 6.8 g kg −1 for linoleate. The lack of major differences between the 1%‐ and 2%‐linolenate lines indicated that it should be possible to develop acceptable cultivars with <20 g kg −1 linolenate.