Genetic Control of High Oleic Acid Content in the Seed Oil of Two Soybean Mutants

Abstract

Soybean [Glycine max (L.) Merr.] oil with high content of oleic acid (>300 g kg−1) is less susceptible to oxidative changes during refining, storage, and frying. Two mutants (M23 and M11) were developed that had high content of oleic acid in the seed oil compared with the original cultivar (Bay). The objective of this study was to compare the genetic control of oleic acid content in these mutants. Reciprocal crosses 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, F1, and F2 seeds from the cross between M23 and Bay and between M11 and Bay indicated that oleic acid content was controlled by a single gene. The cross between M23 and M11 indicated that each mutant 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 dominant to the allele ol for high oleic acid content in M23 but completely dominant to the allele ola for high oleic acid content in M11. The allele ola in M11 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 ol and ola may also control the linoleic acid content by blocking the synthesis of this acid at the step of oleic acid desaturation.