Abstract
The mode of inheritance of lipoxygenase-2 (L-2) in soybean seeds was determined from progeny of a cross between PI 86023 (L-2-less) and Suzuyutaka (normal) soybeans. Immunological and electrophoretic analyses of F2 and F3 seeds from the cross indicated that the absence of L-2 isozyme was due to a single allele recessive to an allele controlling the presence of the isozyme. The gene symbols. Lx2 and lx2 are assigned to the alleles for the presence and absence of L-2 isozyme, respectively. Electrophoretic analysis of a total of 474 F2 seeds from the reclprocal crosses between PI 86023 (L-2-less) and Tohoku N0.74 (L-3-less) indicated that the Lx2 locus is independent of the Lx3 locus. Electrophoretic analysis of a total of 157 F2 seeds from the cross between PI 86023 and a L-1 ?? -3-less double mutant line indicated that the Lx3 locus is independent of the Lx1 and Lx2 loci, respectively, being consistent with the no linkage between the Lx2 and Lx3 loci indicated by the analysis of F2 seeds from the former reciprocal crosses. In this study, two types of double mutant seeds were identified that lacked both L-1 and L-3, and both L-2 and L-3 isozymes at the same time. However, no double mutant seeds were identified that lacked both L-1 and L-2 isozymes, so far. The L-1.L-3-less and L-2.L-3-less double mutant seeds germinated, grew and matured normally to produce F3 seeds that lacked both L-1 and L-3, and both L-2 and L-3 isozymes, respectively.
