Identification and Confirmation of QTLs Associated with Soybean Protein and Oil Content (Glycine Max).

Soybean [Glycine max (L.) Merr.] is a very important economic crop due to its low cost, high protein and oil content. Identification and utilization of molecular markers flanking quantitative trait loci (QTL) of these traits can facilitate soybean breeding. The objectives of this research are to confirm previously reported QTL controlling soybean protein and oil content and identify new QTL associated with soybean protein and oil content.

A total of 250 F2-derived recombinant inbred lines (RILs) from two mapping populations (R05-1415 x R05-638 and R05-4256 x V97-1346) with contrasting protein and oil content (high protein and low oil × low protein and high oil) will be used for genotyping and phenotyping. Each line was grown in a 10-foot row plot in Stuttgart, AR and Kaiser, AR with two replications in 2011. Protein and oil content were measured by using standard near-infrared transmittance technique. Field experiment will be repeated in 2012.

Approximately 600 SSR markers spanning 20 molecular linkage groups (MLG) of soybean genetic map will be chosen to screen the parental genotypes for polymorphism. SSR markers will be selected every 5 centimorgan (Appendix 3). SSR markers that show polymorphism in parental genotypes will be used to screen the RILs. After getting genotypic and phenotypic data, JoinMap 3.0 and Win QTL Cartographer for single marker analysis, composite interval mapping, and multiple interval mapping will be used to identify QTL associated with protein and oil.