Validation of Quantitative Trait Loci Associated with Seed Size, Protein and Sucrose Content in Soybean (Glycine max).

High seed protein and sucrose content as well as suitable seed size are currently the main food-grade soybean breeding targets. Identification and utilization of molecular markers linked to these traits can help understand the genetic basis of seed quality traits and their response in different environments, and consequently facilitate food-grade soybean breeding selection. A set of F _4:6 98 recombinant inbred lines (RIL) derived from a cross between a high protein breeding line R95-1705 and a large seeded cultivar MFL-552 with high sucrose content, were used to confirm previously published Quantitative Trait Loci (QTL) for the three traits. The F _4:6 RIL population was grown in Fayetteville and Stuttgart, AR in 2007. Seed sucrose content was determined by High Performance Liquid Chromatography and seed protein was obtained using a Near Infrared (NIR) analyzer. Seed size (range 13.07-22.5 g/100 seeds; mean 17.6 g/100 seeds), protein content (range 42-52 %, mean 47.2 %) and sucrose content (range 1.08-5.92 %, mean 3.6 %) exhibited a normal distribution. Parental genotypes were screened with 77 SSR markers, previously reported to be linked to QTL for seed size, seed sucrose or seed protein. Thirty-five markers were polymorphic between parents. Progeny lines have been screened with these polymorphic markers. Single marker QTL analysis data will be presented.