| Authors: | Panthee, D.R., Pantalone, V.R., West, D.R., Saxton, A.M., Sams, C.E. |
| Abstract: | Soybean [Glycine max (L.) Merr.] is an important crop because of its high oil and protein concentration. However, there is an inverse relationship between seed protein and oil concentration, making it difficult to improve both traits simultaneously. Molecular breeding may be helpful to facilitate a balanced accumulation of desirable alleles. The objective of this study was to identify quantitative trait loci (QTL) governing soybean protein, oil and seed size. To achieve this objective, 101 F6–derived recombinant inbred lines (RIL) from a population developed from a cross of N87-984-16 x TN93-99 were used. Heritability estimates on an entry mean basis for protein and oil concentrations, and seed size were 0.66, 0.54, and 0.71, respectively. A total of 585 simple sequence repeat (SSR) molecular genetic markers were screened and 94 were polymorphic in the RIL. Single factor ANOVA was used to identify candidate QTL, which were then confirmed by composite interval mapping. One novel molecular marker (Satt570) on molecular linkage group (MLG) G associated with a protein QTL was detected. Novel molecular markers (Satt274, Satt420, and Satt479) located on MLG D1b, O, and O respectively and a previously reported marker (Satt317) located on MLG H were associated with oil QTL in this study. Molecular markers Satt002 (MLG D2) and Satt184 (MLG D1a) associated with seed size QTL were verified whereas Satt147 (MLG D1a) was novel. The individual QTL explained 20.2, 9.4-15, and 10 to 16.5% of the phenotypic variation for protein and oil concentrations, and seed size, respectively. Thus, we identified major loci for improving soybean seed quality. |