Two mapping approaches were use to identify and validate milling and baking quality QTL in soft wheat. Two LG were consistently found important for multiple traits and we recommend the use marker-assisted selection on specific markers reported here. Wheat-derived food products require a range of characteristics. Identification and understanding of the genetic components controlling end-use quality of wheat is important for crop improvement. We assessed the underlying genetics controlling specific milling and baking quality parameters of soft wheat including flour yield, softness equivalent, flour protein, sucrose, sodium carbonate, water absorption and lactic acid, solvent retention capacities in a diversity panel and five bi-parental mapping populations. The populations were genotyped with SSR and DArT markers, with markers specific for the 1BL.1RS translocation and sucrose synthase gene. Association analysis and composite interval mapping were performed to identify quantitative trait loci (QTL). High heritability was observed for each of the traits evaluated, trait correlations were consistent over populations, and transgressive segregants were common in all bi-parental populations. A total of 26 regions were identified as potential QTL in the diversity panel and 74 QTL were identified across all five bi-parental mapping populations. Collinearity of QTL from chromosomes 1B and 2B was observed across mapping populations and was consistent with results from the association analysis in the diversity panel. Multiple regression analysis showed the importance of the two 1B and 2B regions and marker-assisted selection for the favorable alleles at these regions should improve quality.

Information on the genetic control of the quality traits of soft wheat (Triticum aestivum) is essential for breeding. Our objective was to identify QTL associated with end-use quality. We developed 150 F4-derived lines from a cross of Pioneer 26R46 × SS550 and tested them in four environments. We measured flour yield (FY), softness equivalent (SE), test weight (TW), flour protein content (FP), alkaline water retention capacity (AWRC), and solvent retention capacity (SRC) of water (WA), lactic acid (LA), sucrose (SU), sodium carbonate (SO). Parents differed for nine traits, transgressive segregants were noted, and heritability was high (0.67 to 0.90) for all traits. We detected QTL distributed on eight genomic regions. The QTL with the greatest effects were located on chromosome 1A, 1B, and 6B with each affecting at least five of ten quality traits. Pioneer 26R46 is one of the best quality soft wheats. The large-effect QTL on 1A novel and accounted for much of the variation for AWRC (r2 = 0.26), SO (0.26) and SE (0.25), and FY (0.15) and may explain why Pioneer 26R46 has such superior quality. All alleles that increased a trait came from the parent with the highest trait value. This suggests that in any population that marker-assisted selection for these quality traits could be conducted by simply selecting for the alleles at key loci from the parent with the best phenotype without prior mapping.

No abstract

Information on the genetic control of the quality traits of soft wheat (Triticum aestivum L. em. Thell) is essential for breeding. Gluten strength is a measure of quality and has particular relevance to soft wheat as identity-preserved programs for strong-gluten soft red winter wheat in the eastern US that is essential to effective biscuit industry. Identifying areas of the soft wheat genome harboring genes for functional end-use quality may assist in selective breeding and in understanding the genetic components of this trait. Our objective was to identify Quantitative Trait Loci associated with end-use quality.We developed 150 F4-derived lines from a cross of Pioneer 26R46 × SS550 and tested them in four environments. We measured flour yield (FY), softness equivalent (SE), test weight (TW), flour protein content (FP), alkaline water retention capacity (AWRC), and solvent retention capacity (SRC) of water (WA), lactic acid (LA), sucrose (SU), sodium carbonate (SO) SRCs. Analyses of variance for the ten quality parameters detected a significant difference between parental means for nine traits except for FP. Recombinant inbred lines presented transgressive segregation and high heritability (0.67 to 0.90) for all traits. Strong positive correlations between AWRC with WA, SO, SU and strong negative correlations of FY with AWRC and the SRC traits were observed. We report 28 marker-trait associations. Many QTL were coincident and in accordance with the trait correlations. There were 10 marker-trait associations from four regions for these traits and only one was not coincident with another.We detected QTL distributed on 8 chromosomes. Loci associated with FP mapped on chromosomes 2B, 5A and 5D explained 16 %, 10 % and 12.9 % of the variation for this trait, respectively. QTLs on chromosome 2B co-segregated for SE. SE was negatively correlated (-0.26) with FP. A positive significant correlation between FP and LA (0.36) was detected, yet; the QTL for these two traits were not coincident in this study. The QTL with the greatest effects were located on chromosome 1A, 1B, and 6B with each affecting at least five of ten quality traits. In particular, QTL with the largest effect on LA and consequently gluten strength were on chromosomes 1A with LOD 9 that explained 42.6 % of LA variation and QTLs on chromosome 1B with LOD 9 that explained 33 % of the variation in LA. Loci on chromosomes 1A and 1B were also important contributors of additive effects for this trait with an increase of 6.5 % and 5.6 %, respectively. The largest QTL on 1A co-segregated for AWRC (25 %), SO (26 %) and SE (25 %), and FY (15 %) may explicate why Pioneer 26R46 has such superior quality. All alleles that increased a trait came from the parent with the highest trait value. This suggests that in any population that marker-assisted selection for these quality traits could be conducted by simply selecting for the alleles from the parent with the best phenotype. AWRC and the SRC traits were observed. We report 28 marker-trait associations. Many QTL were ...

Information on the genetic control of the quality traits of soft wheat (Triticum aestivum L. em. Thell) is essential for breeding. Gluten strength is a measure of quality and has particular relevance to soft wheat as identity-preserved programs for strong-gluten soft red winter wheat in the eastern US that is essential to effective biscuit industry. Identifying areas of the soft wheat genome harboring genes for functional end-use quality may assist in selective breeding and in understanding the genetic components of this trait. Our objective was to identify Quantitative Trait Loci associated with end-use quality.We developed 150 F4-derived lines from a cross of Pioneer 26R46 × SS550 and tested them in four environments. We measured flour yield (FY), softness equivalent (SE), test weight (TW), flour protein content (FP), alkaline water retention capacity (AWRC), and solvent retention capacity (SRC) of water (WA), lactic acid (LA), sucrose (SU), sodium carbonate (SO) SRCs. Analyses of variance for the ten quality parameters detected a significant difference between parental means for nine traits except for FP. Recombinant inbred lines presented transgressive segregation and high heritability (0.67 to 0.90) for all traits. Strong positive correlations between AWRC with WA, SO, SU and strong negative correlations of FY with AWRC and the SRC traits were observed. We report 28 marker-trait associations. Many QTL were coincident and in accordance with the trait correlations. There were 10 marker-trait associations from four regions for these traits and only one was not coincident with another.We detected QTL distributed on 8 chromosomes. Loci associated with FP mapped on chromosomes 2B, 5A and 5D explained 16 %, 10 % and 12.9 % of the variation for this trait, respectively. QTLs on chromosome 2B co-segregated for SE. SE was negatively correlated (-0.26) with FP. A positive significant correlation between FP and LA (0.36) was detected, yet; the QTL for these two traits were not coincident in this study. The QTL with the greatest effects were located on chromosome 1A, 1B, and 6B with each affecting at least five of ten quality traits. In particular, QTL with the largest effect on LA and consequently gluten strength were on chromosomes 1A with LOD 9 that explained 42.6 % of LA variation and QTLs on chromosome 1B with LOD 9 that explained 33 % of the variation in LA. Loci on chromosomes 1A and 1B were also important contributors of additive effects for this trait with an increase of 6.5 % and 5.6 %, respectively. The largest QTL on 1A co-segregated for AWRC (25 %), SO (26 %) and SE (25 %), and FY (15 %) may explicate why Pioneer 26R46 has such superior quality. All alleles that increased a trait came from the parent with the highest trait value. This suggests that in any population that marker-assisted selection for these quality traits could be conducted by simply selecting for the alleles from the parent with the best phenotype. AWRC and the SRC traits were observed. We report 28 marker-trait associations. Many QTL were ...