Soybean QTL for yield and yield components associated with Glycine soja alleles

U.S. soybean [Glycine max (L.) Merr.] germplasm has a narrow genetic base. The objective of this study was to identify G. soja Sieb. and Zucc. alleles for yield and yield component quantitative trait loci (QTL). Two populations of BC₂F₄ lines were generated from a mating between recurrent parent G. max '7499' and donor parent G. soja PI 245331 with one line in each population tracing back to the same BC₂ plant. Population A was used for the QTL identification analysis and Population B was used for the QTL verification test. The Population A lines were genotyped at 120 simple sequence repeat marker loci and one phenotypic marker locus. There were 11 putative QTL significantly associated with yield and yield component traits across three environments. One QTL for seed yield was found using the combined data. At this locus, the G. soja allele at Satt511 on LG A1 was associated with increased seed yield with an additive yield effect of 191 to 235 kg ha^-1 depending on the QTL analysis method. Across environments in the validation population, lines that were homozygous for the G. soja allele at Satt511 demonstrated a 6.3% yield increase over lines that were homozygous for the G. max allele. One seed filling period QTL was identified on LG F with an additive effect of +1 d. This QTL also provided a +1 d additive effect on maturity. These results demonstrate the potential of identifying positive alleles in the exotic germplasm of soybean.