Background: The production of soy-based food products requires specific physical and chemical characteristics of the soybean seed. Identification of quantitative trait loci (QTL) associated with these traits, such as seed weight,seed protein and sucrose concentrations could accelerate the development of competitive high quality soybean cultivars for the food-grade market through marker-assisted selection (MAS). The objectives of this study were to identify and validate QTL associated with these value-added traits in two high-protein recombinant inbred line (RIL) populations.
Results:Two RIL populations were derived from the high-protein cultivar ‘AC X790P’ (49% protein, dry weight basis), and two high-yielding commercial cultivars, ‘S18-R6’ (41% protein) and ‘S23-T5’ (42% protein). Fourteen large-effect QTL (R2>10%) associated with seed protein concentration were identified. Five of these protein-related QTLwere co-localized with QTL associated with seed sucrose concentration or seed weight. None of the protein-related QTL did not co-localize with seed yield QTL in either population. Sixteen candidate genes with putative roles in protein metabolism were identified within seven of these protein-related regions: qPro_Gm02-3, qPro_Gm04-4, qPro_Gm06-1, qPro_Gm06-3, qPro_Gm06-6, qPro_Gm13-4 and qPro-Gm15-3.
Conclusion:The use of RIL populations derived from high-protein parents created a unique opportunity to identify novel QTL that may have been masked by large-effect QTL segregating in populations developed from diverse parental cultivars. Nine QTL associated with seed protein concentration were identified and validated in both high-protein RIL populations. These QTL may be useful in the curated selection of new soybean cultivars for optimized soy-based food products.