Identification and Confirmation of Quantitative Trait Loci for Protein Concentration and Improved Amino Acid Composition in <i>Glycine max</i>

The demand for poultry and swine production has grown continually as the world population increases. There will be an estimated 8 billion people to feed in the world by 2025. Soybean meal is the most important plant protein ingredient for poultry and swine feedstock. Globally, the US produces 32% of the world’s soybean. Although soymeal is nearly a complete plant protein, it is highly supplemented with sulfur-containing amino acids such as cysteine and methionine. The objectives of this project were to utilize molecular markers known as single nucleotide polymorphisms (SNPs) to identify genomic regions associated with protein concentration and amino acid composition. A total of 302 recombinant inbred lines (RIL) were developed from a cross between Essex and Williams 82. F_5:8 [8^th generation of filial generation 5 derived plants] and F_5:11 [11^th generation of filial generation 5 derived plants] lines were used to identify, verify and confirm quantitative trait loci (QTL) associated with protein concentration and amino acid composition.

RILs were genotyped with >50,000 SNPs and 17,232 were polymorphic. A total of 9 seed protein QTLs were detected; the QTLs explained 3.1% to 9.8% of variation in seed protein. There were nine seed oil QTL detected which explained 3.2% to 14.1% of the variation in seed oil. No yield QTL were detected. A total of 32 seed amino acid QTLs were detected which explained 4.5% to 14.3% in seed amino acid composition. One seed protein QTL was confirmed on Gm 7. We propose the gene symbol cqSeed Protein-004. Four seed protein QTLs and three seed oil QTLs were positionally confirmed in this study.