Agronomic and seed traits of 1%-linolenate soybean genotypes

An oil from soybean [Glycine max (L.) Merr.] cultivars with <20 g kg(-1) li nolenate would have a desirable oxidative stability. The objective of our s tudy was to compare the agronomic and seed traits of lines with the genotyp e 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 populatio ns were developed by crossing three high-yielding, recurrent parents with a pproximate to 25 g kg(-1) linolenate to a donor line with approximate to 13 g kg(-1) linolenate. For each population, 27 1%- and 27 2%-linolenate BC1F 2:4 lines were evaluated at Ames, Grand Junction, and Hubbard, IA during 19 '98. The mean seed yields of the 1%-linolenate lines were 47 kg ha(-1) lowe r in Population 1, 65 kg ha(-1) lower in Population 2, and 164 kg ha(-1) lo wer in Population 3 than the 2%-linolenate lines, but the difference was on ly significant in Population 3. The maximum mean differences between the 1% - and 2%-linolenate lines in any of the populations for the remaining agron omic and seed traits were id 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 an d 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 diff erences between the 1%- land 2%-linolenate lines indicated that it should b e possible to develop acceptable cultivars with <20 g kg(-1) linolenate.