QTL Mapping for Protein and Sulfur-Containing Amino Acid Contents Using a High-Density Bin-Map in Soybean (Glycine max L. Merr.)

Soybean
provides essential protein and amino acids for humans and
animals, while sulfur-containing amino acids (SAA), including methionine
(Met) and cysteine (Cys), are very limited. In this study, we constructed
a high-density bin-map with 3420 bin markers using 676 857
SNPs of a recombinant-inbred line (RIL) population derived from a
cross between Kefeng no. 1 and Nannong 1138-2. Quantitative trait
loci (QTL) mapping was performed for Cys, Met, SAA, and the protein
content using this high-density bin-map. Twenty-five QTLs linked to
these four traits were identified, and four genomic regions located
on chromosomes (Chr) 07, 08, 15, and 20 were overlapped by multiple
QTLs. Among them, bin 115–124 located on Chr 15 was associated
with all four traits and was a novel locus with a high LOD value.
These findings will provide a basis for nutritional quality improvement
using marker-assisted selection breeding and clarify the genetic mechanisms
of SAA and protein in soybean.