Files
Abstract
Soybean is an important protein source for human and animal nutrition. To improve the protein content, it is important to understand this trait genetics. A multiparent population with 1115 recombinant inbred lines (RILs) was evaluated for two years and genotyped with molecular markers aiming to introgress the ‘Danbaekkong’ chromosome 20 QTL and determine its effects. Based on published results, a marker targeting the gene Glyma.20g085100 was developed to track the high protein allele. The QTL increased the protein by 3.3% on average, but yield was penalized. However, it was possible to identify lines with high protein and yield. The Danbaekkong allele was demonstrated to have originated from Glycine soja (PI 163453) and it is present in 79 G. soja accessions but absence in 35 G. max ancestors of North America cultivars.G. soja is a valuable source of alleles for protein improvement. The second objective was to map protein and sulfur-containing amino acids QTLs. The RIL population Woodruff × PI 399000 was evaluated in six environments and genotyped with the SoySNP6K BeadChip. Three protein QTLs were identified on chromosomes (Chrs) 6, 15 and 17 and two QTLs on Chrs 6 and 10 for cysteine and methionine. The QTLs from PI 399000 increase protein without decreasing concentration of cysteine and methionine. Markers linked to the QTLs can be used to improve seed composition.