Family and line selection for elevated palmitate of soybean

Soybean [Glycine max (L.) Merr.] oil with elevated palmitate content is more oxidatively stable than conventional soybean oil. The objective of this study was to compare the family and line methods of selection for elevated palmitate content in four populations segregating for the major genes fap2-b and fap4 and for modifying genes that influence the trait. Five random F-3-derived lines from each of 20 F-2 families were evaluated in replicated tests during 2 yr at two locations. For the family method, the mean palmitate content of the five F-3-derived lines of each F-2 family was computed for individual replications and the mean of two replications at each environment. For families with greater than or equal to 250 g kg(-1) palmitate, lines with greater than or equal to 250 g kg(-1) were selected. For the line method, lines with greater than or equal to 250 g kg(-1) were chosen without regard to the F-2 family mean. The palmitate contents of the selected and unselected lines based on data from one environment were compared with their mean palmitate content in the other three test environments. There were 50% of the lines incorrectly rejected by the family method and 31% by the line method. Of the lines chosen, 63% were correctly selected by the family method and 60% for the line method. For development of cultivars with elevated palmitate, breeding methods that rely on family performance would not be more effective or efficient than methods that ignore family structure.