Identification and Fine Mapping of a Soybean Seed Protein QTL from PI 407788A on Chromosome 15

Soybean [Glycine max (L.) Merr.] is grown primarily as a source of protein and oil. The objectives of this study were to identify soybean seed protein quantitative trait loci (QTL) from the high protein line PI 407788A and to fine map an important QTL for protein on chromosome (chr) 15. The mapping was done in a population of inbred lines developed with one backcross (BC1) using Williams 82 as a recurrent parent and the high protein source PI 407788A as a donor parent. The population was evaluated with genetic markers and for seed protein and oil concentrations in three Illinois locations in 2005 and 2006. The location of the major protein QTL on chr 15 was fine mapped by evaluating six families of lines segregating for sections of the QTL interval in Illinois during 2008. Genetic marker analysis of the BC1 population revealed the locations of significant protein and oil QTL on chr 20 and 15 within regions where QTL for these traits were previously mapped. Fine mapping of the chr 15 QTL placed it in a 535 kb interval between BARCSOYSSR_15_0161 and BARCSOYSSR_15_0194 based on the Glyma. Wm82.a2 assembly. This fine mapping information will be useful in marker-assisted selection and efforts to clone the QTL.