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The protein content of cultivated wheat ( Triticum aestivum L.) is an important determinant factor of the nutritional value of the grain and the technological properties and rheological properties of flour. In order to examine the genetic basis of protein content, we searched for grain protein content quantitative trait loci (QTLs) and flour protein content QTLs in a newly developed doubled haploid (DH) line and identified the genetic correlation between grain protein content and flour protein content in the same DH population. Both the DH population and its parental lines were evaluated for grain protein content and flour protein content in three field trials. Four additive effect QTLs, two pairs of epistatic QTLs, and two QTLs × environment (QE) interaction for grain protein content were identified. The model explained 51.52% of the phenotypic variation (PVE), with epistatic effects being better explained by the higher PVE than additive effects. Four additive effect QTLs, five pairs of epistatic QTLs, and one QE were detected for flour protein content. The model explained 45.8% of the PVE. Of the 15 QTLs identified, three additive QTLs and one pair of epistatic QTLs were determined for both grain protein content and flour protein content; of these, the QTLs for protein content were considered to be more 'stable' than those detected for only grain protein content or for only flour protein content. The data reported here may be useful for manipulating the QTLs for protein content by marker-assisted selection in future wheat breeding programs. [ABSTRACT FROM AUTHOR]

Flour color is an important trait in the assessment of flour quality for the production of many end products. In this study, quantitative trait loci (QTLs) with additive effects, epistatic effects, and QTL × environment (QE) interactions for flour color in bread wheat ( Triticum aestivum L.) were studied, using a set of 168 doubled haploid (DH) lines derived from a Huapei 3 × Yumai 57 cross. A genetic map was constructed using 283 simple sequence repeats (SSR) and 22 expressed sequence tags (EST)-SSR markers. The DH and parents were evaluated for flour color in three environments. QTL analyses were performed using QTLNetwork 2.0 software based on a mixed linear model approach. A total of 18 additive QTLs and 24 pairs of epistatic QTLs were detected for flour color, which were distributed on 19 of the 21 chromosomes. One major QTL, qa1B, closely linked to barc372 0.1 cM, could account for 25.64% of the phenotypic variation of a* without any influence from the environments. So qa1B could be used in the molecular marker-assisted selection (MAS) in wheat breeding programs. The results showed that both additive and epistatic effects were important genetic basis for flour color, and were also sometimes subject to environmental modifications. The information obtained in this study should be useful for manipulating the QTLs for flour color by MAS in wheat breeding programs. [ABSTRACT FROM AUTHOR]

Protein hydrolysis is widely used in the food industry to improve food or industrial quality, and processing is carried out concurrently or subsequently to starch pasting. Inthis study,QTLmapping of the pasting properties of natural wheat flour (NWF) and papain-treated flour (PTF) was performed in three environments. These analyses involved a set of 173 F9:10 recombinant inbred lines (RILs) derived from "Shannong01-35×Gaocheng9411" witha genetic linkagemapconsisting of 6248 molecular markers. The additive, epistatic, and epistatic×environment interaction effects of QTLs for pasting properties were analyzed. A total of 43 and 31 additive QTLs for pasting properties were detected using NWF and PTF, respectively. QPv1A.4-1, QPv4B.4-17, QTv1A.4-1, QTv4B.4-17, QSb4B.4-17, QPt1A.4-1, and QPt4B.4-17 were identified using both NWFand PTF. In contrast, QPv6A.2-128, QTv6A.2-128, QFv6A.2-75, and QBd6A.2-128 were only identified in wheat flour; thus, these QTLs are related to the papain digestion site. Five and eight pairs of epistatic interaction QTLs were identified in NWF and PTF, respectively. QPv1A.4-1/QPv4B.4-17 and QTv1A.4-1/QTv4B.4-17 were identified in NWF and PTF, whereas, QInA1A.4-1 and QInA4B.4-17 were only detected in PTF. Two and three pairs of epistatic×environment interactions were detected inNWFandPTF, respectively. In the present study, two importantQTLclusters (≥3QTLs) were detected from NWF, and three clusters were detected from PTF. The results of the comprehensive evaluation of protein hydrolysis and starch pasting provide valuable information to facilitate the improvement of wheat flour quality and promote the molecular breeding of wheat. [ABSTRACT FROM AUTHOR]