|Oltmans-Deardorff, Sheilah -|
|Fehr, Walter -|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 30, 2012
Publication Date: August 21, 2012
Citation: Oltmans-Deardorff, S.E., Fehr, W.R., Shoemaker, R.C. 2012. Marker-assisted selection for elevated concentrations of the a' subunit of B-conglycinin and its influence on agronomic and seed traits of soybean. Crop Science. 53:1-8. Interpretive Summary: Soybean seed contains approximately 40% of high quality protein. Some components of the protein may provide health benefits to soybean protein consumers. A mutant was discovered that has elevated concentrations of a particularly good subunit. In this study the authors identified and tested molecular markers that will help soybean breeders select for the elevated protein subunit without going through the costly biochemical analyses to select for improved lines. The authors also evaluated 16 combinations of gene mutations to determine the impact of the subunit variants on yield and soybean vigor. They determined that it is possible to breed for the elevated subunit with no cost to yield. This information will be used by breeders interested in improving the quality of soybean protein.
Technical Abstract: Soybean [Glycine max (L.) Merr.] cultivars with elevated concentrations of the a' subunit of ß-conglycinin (BC) may provide health benefits to soy protein consumers. Two Monsanto single nucleotide polymorphism markers were used to classify F2 plants in four segregating populations as having elevated a' (EAP) or normal a' (NAP) concentrations. Seeds from one F3 progeny of each F2 plant were analyzed for protein composition by sodium dodecyl-sulfate polyacrylamide gel electrophoresis. Of the 800 plants in the four populations evaluated with the two markers, 82% were correctly classified for the EAP trait and 80% for the NAP trait. The EAP and NAP traits were evaluated in combination with the four glycinin genotypes gy1,2, Gy3, gy4, Gy5; gy1,2, Gy3, gy4, gy5; gy1,2, gy3, gy4, Gy5; and gy1,2, gy3, gy4, gy5. The seed yield, time of maturity, and protein and oil concentration were evaluated for 18 F3:5 lines in each of the eight genotypic classes of the four populations at three environments in 2011. The EAP trait resulted in a significant increase in the a' and ß subunits of BC and a decrease in the a’ subunit, with no consistent impact on total BC, total glycinin, seed yield, maturity, and protein and oil concentrations. It should be possible to develop acceptable soybean cultivars that have the EAP trait in combination with the glycinin genotype gy1,2, gy3, gy4, gy5 to obtain a high concentration of the a' subunit and total BC with no glycinin for soy-based food products.