Combining Ability in Loci for High Oleic and Low Linolenic Acids in Soybean

Abstract

Two soybean [Glycine max (L.) Merr.] germplasm lines have been identified for unique fatty acid content. The contents of oleic and linolenic acids in HOLL are controlled by ol and fan loci, respectively, and the very low content of linolenic acid in LOLL is controlled by fan and fanxa loci combined. The fan locus is identical for both HOLL and LOLL. Therefore, if ol and fanxa loci are independent, soybean germplasm could be developed with more unique and useful combinations of these fatty acids. The objectives of this study were to combine the loci of high oleic and low linolenic acids, and determine the effects of altered contents of oleic and linolenic acids on other fatty acids. HOLL was reciprocally crossed to LOLL. The data from F2 seed indicated that the ol locus controlling high oleic acid was independently inherited from the fanxa locus controlling low linolenic acid. Thus, the germplasm (DHL) with the high oleic acid trait from HOLL, and very low linolenic acid trait from LOLL, was easily developed. The increases in oleic acid due to ol was associated completely with changes in linoleic acids, indicating a pleiotropic effect of the ol locus. Decreases in linolenic acid due to fan and fanxa were associated primarily with increases in linoleic acid. The development of DHL with increased contents of oleic acid and decreased contents of polyunsaturated fatty acids could open new markets for soybean oil.