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Inheritance of a Lipoxygenase‐1 Allozyme in Soybean
Author(s) -
Pfeiffer T. W.,
Hildebrand D. F.,
Orf J. H.
Publication year - 1993
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1993.0011183x003300040009x
Subject(s) - biology , lipoxygenase , genotype , genetics , isozyme , locus (genetics) , allele , isoelectric focusing , botany , gene , biochemistry , enzyme
Three soybean [ Glycine max (L) Merr.] seed lipoxygenase isozymes, involved in generating products which contribute to undesirable flavors in processed protein products, have been characterized genetically. The objective of this study was to determine the inheritance of an alternate lipoxygenase‐1 allozyme, which has a more acidic isoelectric point than the normal allozyme (pI 5.79 vs. pI 5.85 for the normal allozyme). This alternate allozyme was originally seen in soybean strains L 2 ‐3 and PI 86023, which are null for lipoxygenase‐2, genotype lx 2 lx 2 . A similar alternate allozyme was subsequently seen in ‘McCall’. The 1:2:1 F 2 segregation ratios from several crosses of “normal” allozyme × alternate allozyme parents indicated codominant inheritance of the two allozymes. The gene symbol Lx b 1 is assigned to the allozyme with pI 5.79, and the gene symbol for the allozyme with pI 5.85 becomes Lx a 1 This gives an allelic series at the lipoxygenase‐1 locus Lx a 1 , Lx b 1 , and lx 1 . The lx 1 and lx 2 loci are very tightly linked. Crosses between Lx a 1 Lx a 1 Lx 2 Lx 2 and Lx b 1 Lx b 1 lx 2 lx 2 genotypes would be designed to incorporate the lx 2 lx 2 genotype into cultivars with improved protein flavor attributes for soyfood products. while phenotypes of Lx 2 Lx 2 and lx 2 lx 2 genotypes are indistinguishable in terms of lipoxygenase‐2, the presence of two electrophoretic bands for lipoxygenase‐1 ( Lx a 1 Lx b 1 ) when the lipoxygenase‐2 locus is also heterozygous makes it possible to identify individuals with the recessive lx 2 allele. The selection of heterozygotes can reduce the time needed to backcross the lx 2 allele.