Combining ability in loci for high oleic and low linolenic acids in soybean

Two soybean [Glycine mar (L.) Merr.] germplasm lines have been identified f or unique fatty acrid content. The contents of oleic and linolenic acids in HOLL are controlled by ol and fan led, respectively, and the very low cont ent of linolenic add in LOLL is controlled by fan and fanx(a) loci combined . The fan locus is identical for both HOLL and LOLL, Therefore, if ol and f anx(a) loci are independent, soybean germplasm could be developed with more unique and useful combinations of these fatty acids. The objectives of thi s 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 S s eed indicated that the ol locus controlling high oleic acid was independent ly inherited from the fanx(a) locus controlling low linolenic acid, Thus, t he germplasm (DHL) with the high oleic acid trait from MOLL, and very low l inolenic acid trait from LOLL, was easily developed. The increases in oleic acid due to ol was associated completely with changes in Linoleic acids, i ndicating a pleiotropic effect of the ol locus. Decreases in linolenic acid due to fan and fanx(a) were associated primarily with increases in linolei c acid. The development of DHL with increased contents of oleic acid and de creased contents of polyunsaturated fatty acids could open new markets for soybean oil.