Genetic Variation for Modifiers Controlling Reduced Saturated Fatty Acid Content in Soybean

Abstract

Soybean [Glycine max (L.) Merr.] oils with reduced palmitic acid concentrations should comply with U.S. Food and Drug Administration (FDA) regulations for vegetable oils with lower saturated fatty acid contents. This study was designed to investigate the genetic basis for reduced palmitic and stearic acid contents in the seed oil of reduced palmitic add germplasm, N87-2122-4. Crosses between N87-2122-4 and Midwest-adapted cultivars, Kenwood and P9273, revealed frequencies of reduced and normal palmitic acid among F 2 progeny consistent with segregation at a single major locus. There was a large phenotypic variation (15-30 g kg -1 ) for palmitic acid content measured on progeny homozygous for either reduced or normal palmitic acid alleles, however. Repeatability of this variation was examined in 87 reduced and normal palmitic F 5:7 lines randomly sampled from each cross. Reduced palmitic acid lines ranged between 54 and 72 g kg -1 , and normal palmitic acid lines between 90 and 119 g kg -1 for both crosses. No line produced significantly less palmitic acid than N87-2122-4 but 55% of the reduced palmitic acid lines were significantly greater (P 80%) for palmitic and stearic acid contents suggest that total saturates may be reduced by selection in few environments for major and modifier genes controlling reduced palmitic acid content.