Wheat grain quality has a complex genetic architecture heavily influenced by the growing environment. Consistency in wheat quality not only affects the efficiency of milling and baking but also the quality of end-use products. The objectives of this study were to 1) analyze the different wheat quality parameters in Recombinant Inbred Lines (RILs) grown under different environments, and 2) to identify Quantitative Trait Loci (QTLs) associated with quality stability in RILs grown under different environments. A set of 180 RILs derived from two spring wheat lines "Halberd" and "Len" were grown at Uvalde and College Station TX, in the 2009/2010 growing season and at Chillicothe and College Station TX, in 2010/2011 growing seasons. The experiment was laid out in Randomized Complete Block Design (RCBD) with four replications within each location. Each line was tested for multiple quality traits that included grain hardness, protein content, dough mixing properties and bread baking quality using Single Kernel Characterization System (SKCS), Near-Infrared Reflectance Spectrometry (NIRS) analysis, mixograph and the Sodium Dodecyl Sulfate Sedimentation (SDSS) test. Genetic linkage map construction was carried out with 116 single nucleotide polymorphism (SNP) markers in the RILs. Then composite interval mapping was carried out to identify QTLs associated with quality traits. The SDSS column height was positively correlated across four environments. Similarly, it was found to have significant positive correlation with mixing tolerance and peak time within and also across locations. However, the SDSS was negatively correlated with the hardness index. The protein percent was not significant with any of the quality traits within and across environments. We were able to detect many QTLs for different quality traits but most of them were site specific. Only a few QTLs were consistent across environments. Most of the QTLs for quality traits i.e., SDSS, peak time, mixing tolerance and hardness index were identified on chromosome 1B. We were able to detect overlapped QTLs for SDSS column height and mixing tolerance on chromosome 1B. Furthermore, overlapping QTLs for mixing tolerance and peak time were detected on an unknown chromosome. We also detected overlapping QTLs for hardness index on chromosome 1B. We identified one stable QTL for SDSS column height on chromosome 4B. This QTL was detected based on the coefficient of variation (CV) for SDSS in four different environments.

Wheat (Triticum aestivum. L) is an important cereal, used as staple food and a good source of income in different countries. It is providing food to the one third of world s population. Wheat grain is highly venerated for a number of products. To feed the increasing population of world is a great challenge for researchers. The only way to tackle this challenge is to develop new genotypes with good yield potential and to enhance the potential of available genotypes. Breeding strategies for high potential varieties made on the basis of scientific and agronomic knowledge is good way to achieve this goal. Both quality and quantity of grain are important targets to improve. Genetic analysis is one of best tools to exploit the potential of species for application on commercial scale. It will not only enable us to feed humanity but also direct to use natural resources in proper way.

Wheat (Triticum aestivum L.) is used in diverse baked products that require specific end use quality traits. Kernel texture, flour water absorption capacity, gluten strength, starch composition, and other flour constituents all influence overall flour functionality and dough rheology, specifying both wheat market class and intended end product. Wheat breeders need to develop cultivars with superior end-use quality traits, while also optimizing important agronomic traits. Our first objective was to use a genetic linkage map and 207 recombinant inbred lines (RIL) from a soft white 'Coda' by 'Brundage' cross to identify quantitative trait loci (QTL) for grain, milling, and baking traits. The linkage map was developed using 570 single nucleotide polymorphisms (SNP) and 136 simple sequence repeat markers. The RILs were grown in five locations in Idaho and Washington from 2006 to 2013. We detected three QTL on chromosomes 2D, 4B, and 6B that were consistently associated with multiple end-use quality traits. Our second objective was to use a genetic linkage map and 131 RILs from a soft white 'Louise' by 'Alpowa' cross to identify QTL associated with arabinoxylan content and milling traits. The linkage map consisted of 924 SNPs and 41 linkage groups. This population was grown in three Washington locations from 2011 to 2012. We detected 28 QTL associated with seven arabinoxylan content and milling traits. Our third objective was to use 480 advanced breeding lines and Pacific Northwest cultivars to identify molecular markers associated with 21 end-use quality traits. Genotypic data from the iSelect 90K SNP chip was combined with best linear unbiased predictions of historic phenotypic data from the USDA-ARS Western Wheat Quality Laboratory. Genome-wide association mapping in the R package, genome association and prediction integrated tool (GAPIT), detected significant markers for multiple end-use quality traits on chromosomes1B, 1D, 2D, 5A, 5B, and 7A. An improved understanding of the genetic architecture underlying end-use quality traits in wheat may assist breeders with cultivar development for superior end-use quality, particularly by increasing frequencies of favorable alleles in breeding populations. Cultivars with superior end-use quality will allow US wheat producers to maintain domestic and international markets.

Bread wheat (Triticum aestivum L.) is one of the most important food crops, feeding about 40 % of the world's population. Genetic improvement in wheat focus on three main areas: enhancing yield, overcoming biotic and abiotic stress and improvement end use quality. Grain size is an important physical indicator of seed quality that affects vegetative growth and is frequently related to yield, market grade factors and harvest efficiency. The grain length, width, and area were associated with a 40% variation in the milling quality of Australian winter wheat cultivars. Grain color is also one of important traits affecting flour yield and quality in wheat. For effective improvement of quality and yield of wheat, a plant breeder must have knowledge of inheritance of quality and agronomic traits.

Wheat (Triticum aestivum L.) is one of the most important agricultural commodity crops in Washington. Each year, farmers face various production challenges, including Hessian fly [Mayetiola destructor (Say)], which can lead to devastating crop losses. Resistance genes are the most successful methods to manage and control this insect. Although there are at least 37 known Hessian fly resistance genes (HFR genes), few are deployed in the region, mostly due to a lack of molecular tools to support breeding efforts. Seahawk, a popular soft white spring wheat, contains resistance, but the gene identity is unknown. Using two recombinant inbred populations made from crossing soft white spring wheat cultivar Seahawk to spring club wheat cultivars JD and Melba, we set out to identify the source of resistance in Seahawk and to develop molecular markers that can be used to select for the gene in breeding populations. After acquiring the genetic marker information using Illumina’s 90K SNP technology, we were able to map the resistance gene to the distal end of the short arm of chromosome 6B and created three kompetitive allele specific PCR (KASP) markers that are effective in selecting for this gene in diverse backgrounds. Utilizing the Seahawk/JD population, we also studied how the wheat bread-making locus (wbm) affects the quality of soft white and club wheat. Soft white wheat and club wheat are produced and milled for their weak gluten properties and high starch contents that result in delicate crumb structures when baked. The wbm gene, however, is known to be associated with increased gluten strength properties and was identified in elite bread-making cultivars. At Washington State, the wbm gene is found at higher than expected frequencies among elite club and soft white wheat varieties. After testing the quality parameters of wbm isolines, we found that the locus does not negatively impact soft white wheat flour or dough properties.