INFLUENCE OF REDUCED PALMITATE CONTENT ON AGRONOMIC AND SEED TRAITS OF SOYBEAN

Soybean [Glycine max (L.) Merr.] genotypes with reduced palmitate content have been developed to improve the nutritional characteristics of the seed oil. The objective of the study was to determine the influence of reduced palmitate on agronomic and seed traits of soybean. Three lines homozygous for the fap1 and fap3 alleles (approximate to 40 g kg(-1) palmitate) were crossed to different high-yielding cultivars (approximate to 110 g kg(-1) palmitate). In total, 27 F-4-derived lines with reduced palmitate and 27 lines with normal palmitate content were selected from each of the three single-cross populations. The lines and parents of each population were grown in separate replicated field tests at three locations in Iowa during 1992. The mean seed yield of the reduced-palmitate lines was significantly less than that of the normal-palmitate lines in two of the three populations. The reduced-palmitate lines had significantly greater protein content in two crosses and significantly lower oil content than the normal-palmitate lines in all crosses, The associations of reduced palmitate with agronomic and seed traits could be attributable to pleiotropic effects of the fap1 or fap3 alleles or to possible linkages of the alleles with genes controlling the other traits.