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Evaluation of four biparental soybean populations for identification of seed oil QTL, cytoplasmic effects, and genotype x environment interactions
Soybean [Glycine max (L.) Merr.] seeds are comprised of oils, proteins, and carbohydrates. The oil biosynthesis and storage pathways are complex and involve the cytoplasm, which is inherited maternally in soybean. Two pairs of populations were developed to characterize the high-oil phenotype. The first pair was created from a mating between each of two high-oil lines and Williams 82, and the second pair of populations was created by mating high-oil lines with high-oil lines. The objectives were to (1) determine if cytoplasmic effects were detectable for seed oil concentration, (2) evaluate estimates for heritability and genotypic and phenotypic correlations for seed oil, protein, oil+protein concentration, yield, and 100-seed weight, (3) characterize genotype x environment interactions for seed oil concentration, (4) perform QTL analyses for seed oil, protein, oil+protein concentration, yield, and 100-seed weight, and (5) perform a candidate gene analysis in QTL regions to identify putative genes responsible for oil biosynthesis and storage. The results indicated evidence for significant cytoplasmic effects for total oil concentration. The correlations between seed oil and protein concentrations were consistent with other studies, as were heritability estimates for all traits. Results for all four populations showed significant genotype x environment interactions for seed oil concentration, and stability analyses identified individuals that represent Type 1 or Type 2 stability. The QTL analyses indicated that the two high-oil lines that were crossed with Williams 82 had different sets of alleles responsible for increasing oil. The analyses also indicated that the two high-oil line x high-oil line cross populations had different sets of alleles responsible for oil concentration. All parents contributed alleles for increasing progeny oil, protein, oil+protein concentration, and yield. All but one parent contributed alleles for increasing 100-seed weight. One genomic region was identified that was associated with all traits. Candidate genes were identified that may be causative genes for the oil QTL, which include genes with Arabidopsis thaliana homologs for DGAT enzymes.
Jedlicka, Joseph, "Evaluation of four biparental soybean populations for identification of seed oil QTL, cytoplasmic effects, and genotype x environment interactions" (2014). ETD collection for University of Nebraska - Lincoln. AAI3642776.