GENETIC-CONTROL OF HIGH OLEIC-ACID CONTENT IN THE SEED OIL OF 2 SOYBEAN MUTANTS

Soybean [Glycine max (L.) Merr.] oil with high content of oleic acid ( >300 g kg(-1)) is less susceptible to oxidative changes during refinin g, storage, and frying, Two mutants (M23 and M11) were developed that had high content of oleic acid in the seed oil compared with the origi nal cultivar (Bay). The objective of this study war; to compare the ge netic control of oleic acid content in these mutants, Reciprocal cross es were made between each mutant and Bay and between the two mutants. There were no maternal and cytoplasmic effects for oleic acid content in any of these crosses, The analysis of fatty acid composition of the parents, F-1, and F-2 seeds from the cross between M23 and Bay and be tween M11 and Bay indicated that oleic acid content was controlled by a single gene, The cross between M23 and M11 indicated that each mutan t had a different allele at the same locus for the oleic acid content. The Ol allele for low oleic acid content in Bay was partially dominan t to the allele ol for high oleic acid content in M23 but completely d ominant to the allele ol(2) for high oleic acid content in M11, The al lele ol(2) in hill was completely dominant to the ol allele in the M23 . There was a complete inverse relationship between oleic and linoleic acid contents in both mutants, It indicated that the mutant alleles o l and ol(2) may also control the linoleic acid content by blocking the synthesis of this acid at the step of oleic acid desaturation.