Agronomic and Seed Traits of Soybean Lines Lacking Seed Lipoxygenases

Abstract

Soybean [ Glycine max (L.) Merr.] seeds contain three lipoxygenase isozymes that cause off‐flavors in soy protein‐containing foods. The use of lipoxygenase‐free soybean seed for food applications may be desirable. The objective of this study was to determine the effect of genetically eliminating the lipoxygenase isozymes on agronomic and seed traits of soybean. From the backcross of the three lipoxygenase‐null alleles lx 1 lx 2 lx 3 into ‘IA2020’, 27 BC 1 F 2 ‐derived lines lacking the three isozymes( triple‐null) and 27 BC 1 F 2 ‐derived lines containing the three isozymes (normal) were identified. The lines were evaluated in a replicated test during 1996 at three locations in Iowa. There were significant differences ( P < 0.01) among locations for all traits measured, except maturity. No differences ( P > 0.05) were found between the mean performance of triple‐null and normal lines for seed yield, maturity, lodging resistance, seed weight, and seed protein content. Mean plant height of normal lines was greater ( P < 0.01) than triple‐null lines by 4 cm and mean seed oil content of normal lines was greater ( P < 0.01) than triple‐null lines by 3 g kg −1 . It will be possible to develop seed lipoxygenase‐free soybean cultivars with desirable agronomic and seed characteristics.