Alteration of soybean oil composition by plant breeding

Experimental lines selected from the cross PI 90406 × PI 92567 are being used in an attempt to improve soybean (Glycine max L.] Merr.) oil by altering fatty acid composition through plant breeding. Preliminary evidence shows that the concentration of linolenic acid in soybean oil is reduced by selection for high levels of oleic acid. Levels of poly-unsaturated acids in “high oleic” selections are lower, to various degrees, but the concentration of saturated fatty acids is not different from that of the variety Dare, a representative southern commercial cultivar. In triglyceride from the “high oleic” selection, N70-3436, levels of palmitic, stearic, oleic, linoleic, and linolenic acid are 9.5, 2.0, 40.1, 43.3, and 5.1 mol %, respectively. The types of triglyceride structures observed in the experimental lines which were examined also are changed. The combined level of triolein, monooleyl-dilinolein, and dioleyl-mono-linolein in seed from N70-3436 is doubled and constitutes ca. 50% of the oil.