Genetic Analysis of a Null‐Allele for Lipoxygenase‐2 in Soybean¹

Abstract

Soybean [ Glycine max (L.) Merr.] seeds contain at least three isomeric forms of lipoxygenase. We have identified a soybean line, PI 86.023, which is homozygous for a gene that confers the absence of the lipoxygenase‐2 isozyme. Analysis of electrophoretic banding patterns of seed extracts from the F 2 and F 3 progeny of crosses between PI 86.023 and breeding lines containing null‐alleles for lipoxygenase‐ 1 and ‐3 indicated that this gene was tightly linked to the Lx 1 locus and independent of the Lx 3 locus. We propose that the dominant allele for this gene be called Lx 2 and the recessive null be designated lx 2 . Seeds were identified that lacked both lipoxygenase‐2 and ‐3, but none was found that lacked both lipoxygenase‐1 and ‐2. The lx ‐ 2 null‐allele will be useful for investigating the effect of lipoxygenase‐2 on the production of off‐flavors during processing of soybean products.