Recent Developments in Breeding Soybeans for Improved Oil Quality

Abstract

AbstractSoybean breeding has traditionally focused on improving crop productivity. While this is still the main objective of soybean breeding programs, there is increased emphasis on improving the intrinsic characteristics of the seeds. Breeding goals with respect to oil quality improvement have been threefold: (1) reducing lipoxygenase activity, (2) decreasing linolenic acid concentrations in soybean oil and more recently (3) reducing the saturated fatty acid, palmitate, in soybean oil. The first two are aimed at improving oil flavor and shelf life. The third has been added as a result of medical concerns about excess saturated fats in the human diet. Considerable progress has been made toward achieving all three objectives. Improved soybean germplasm has been released and is being used to develop high yielding cultivars improved oil quality. Null alleles for three lipoxygenase isozymes have been transferred into the cultivar ‘Century’ through backcrossing. Three different germplasm sources have been developed through mutagenesis and selection with low concentrations of linolenic acid (3.0 to 3.5%). This material has been released and is being widely used by public and private breeders to incorporate the low linolenic acid trait into high yielding cultivars. Cultivars with 2% germplasm with lower concentrations of palmitic acid in soybean oil by as much as 50%. In the U.S., soybean oil accounts for about 50% of the palmitic acid in diets. Therefore, reducing palmitic acid in soybean oil could significantly decrease saturated fat consumption without dietary change. Other research in progress includes studies of the genetic inheritance and control oil quality traits and efforts to use molecular genetics to improve oil quality.