1a.Objectives (from AD-416)
Identify oil and meal traits and the genes that influence those traits to improve the quality and value of U.S. soybeans.
1b.Approach (from AD-416)
The proposed studies will build on our observation that pod position along the main stem affects seed composition (protein:oil content) and seed quality (fatty acid composition of the oil and relative content of sulfur-containing amino acids in protein) and that these differences vary among soybean varieties. We will monitor seed fill duration (SFD) as a function of stem position in relation to seed composition. A second parallel but independent approach will be to screen the USDA Soybean Germplasm Collection to identify higher-oil germplasm that also contains adequate protein (to produce a 48% meal) and with high relative S-content. Accessions identified will be used for crosses to generate segregating populations to select genotypes that have increased seed quality. Digestibility and feed efficiency will be examined in chicken feeding experiments conducted in collaboration with colleagues at the University of Illinois.
Plant growth parameters were measured during reproductive development, and at maturity, plants will be harvested and seed produced at the top, middle and bottom of the main stem harvested separately for analysis of composition. In addition, seed from the top and bottom portions of the canopy will be grown under different conditions (e.g., high versus low light, etc) to determine whether initial growth responses such as emergence rate or shoot growth rate differ depending on position at which the seed were produced.