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Increased interest in value-added traits of soft winter wheat (SWW; Triticum aestivum L.), such as white-seed coat and gluten strength, has resulted from economic incentives for these traits. The first objective of this study was to determine whether differences existed between red- and white- seeded progeny of 17 populations. When abiotic and biotic stresses were negligible, significant differences were not detected between red- and white-seeded progeny, except for yield: red-seeded progeny had a significantly higher yield than the white-seeded progeny. However, when abiotic and biotic stresses were larger, the yield of white-seeded progeny was not significantly different from red-seeded progeny and the white-seeded progeny accumulated a significantly greater amount of deoxynivalenol (DON) than red-seeded progeny. Therefore, Kentucky producers should be cautious when considering production of white-seeded cultivars. The second objective of this study was to determine whether early- or late- generation selection for white-seeded progeny produced a higher frequency of superior white-seeded lines. Three selection methods were studied. Late-generation bulk selection produced a significantly lower frequency of superior white-seeded lines (1.7%) than single seed descent (SSD; 13.9%); the early-generation bulk (9.6%) did not differ statistically from either method. Although SSD produced the most superior lines, the utility of SSD breeding will have to be assessed by SWW breeders to justify additional labor and space requirements. The final objective was to determine whether early-generation selection of wheat quality, as determined by wheat meal-based assays, was effective. A cross between a strong gluten soft red winter and a weak gluten soft white winter wheat was examined. Significant correlations and regressions between wheat meal assays and flour-based assays were found. High heritability and realized genetic gains were also observed. Therefore, early-generation selection for quality characteristics appears to be effective.

Little is known about the effects of arabinoxylans (AX) on noodle quality. The aim of this study was to observe interrelationships between wheat flour AX, SRC tests, and noodle quality attributes, and to investigate the use of SRCs to predict cookie diameter. Cookie diameter is the most common index of overall soft wheat quality used in practice. Duplicate samples of 63 soft white wheat (Triticum aestivum) varieties and breeding lines grown at Corvallis in 2002 were selected to study the relationships between flour and noodle characteristics. Kernel hardness was positively correlated with starch damage, total AX and water-extractable AX (WEAX) content but negatively correlated with break flour yield. In this set of samples, despite significant correlations, the sodium carbonate and sucrose SRC tests were not considered to be reliable predictors of cookie diameter due to low numerical correlation coefficients. A modified extraction method for WEAX-SE and WUAX-SE was optimized and reduced in scale. During method development, WUAX 1-SE and WUAX 2-SE fractions that had been treated with protease and amylase respectively were observed using SEHPLC. The equivalent fractions had been discarded in other studies. In this study, AX was found to present in these fractions. A subset of 12 lines was used for further AX extraction. WUAX 2-SE had the highest molecular weight, followed by WUAX1-SE, and then WEAX-SE. The molecular weights of WEAX-SE ranged from approximately 411,305 and 447,282. However, molecular weight of WUAX 1-SE and WUAX 2-SE could not be specifically defined in this study. In addition, WEAX-SE contained a higher degree of substitution than WUAX 1-SE and WUAX 2-SE. For the whole sample set, flour protein content was negatively correlated with ti5A cooked noodle hardness, adhesiveness and chewiness but positively correlated with springiness. At the very low flour protein contents of this sample set, protein composition, which related to lactic acid SRC, became more important for noodle texture. Both starch damage and sodium carbonate SRC were positively correlated with cooked noodle hardness and chewiness at t₀ and t [subscript 15A] Total AX and WUAX were positively correlated with adhesiveness at to, which might result from gummy and sticky characteristics of AX. Using the subset of 12 lines, described above, increased xylose and arabinose contents reflected overall higher AX abundance, and were related to harder kernel texture, poor milling properties. They were also related to higher water, carbonate and sucrose SRCs, and smaller cookie diameter. A/X ratios of WEAX-SE and WUAX 1-SE were positively correlated with flour yield and break flour yield. The WUAX 2-SE fraction seemed to behave different from the WEAX-SE and WUAX 1-SE fractions. The relationships between A/G ratio, and milling characteristics and SRC were opposite to A/X ratios for all fractions. Decreased MW and increased abundance of WUAX in this sample set was related to poorer milling characteristics. There appeared to be no direct systematic relationships between AX and cooked noodle texture parameters in this study. However, AX content appeared to affect noodle texture indirectly, mediated through the effects ofAX on kernel hardness, milling properties, starch damage, reduced FSV, and hence harder noodle texture. Kernel hardness index, flour yield, break flour yield and tisw cooked noodle hardness were able to be predicted with some confidence using stepwise multiple regressions that used selected parameters from the WEAX, WUAX 1-SE and WUAX 2-SE fractions. / Graduation date: 2004

The lack of information regarding the inheritance of the duration and rate of grain filling, and the possible relationship between grain fill and grain protein content in wheat prompted this study. Early maturing Chinese cultivars, 'AI Feng 2' and 'CB 83-52', and late maturing cultivars adapted to Oregon, 'Stephens' and 'Yamhill Dwarf', were examined for vernalization and photoperiod responses. Progeny from a diallel cross of the genotypes was evaluated for grain filling parameters, grain protein content and other agronomic traits for two years. 'Yamhill Dwarf' required six weeks of vernalization, while other cultivars needed only four weeks. The two Oregon developed genotypes were more sensitive to photoperiod than Chinese genotypes. Variation in developmental patterns among genotypes was related to differences in leaf number, spikelet number, rate of spikelet initiation, and rate of grain fill. Compared to solid planting, space-planting reduced the grain filling period. Significant genotypic variation for grain filling rate, duration, and kernel weight was observed in both seasons. Genotype X year interaction was not significant for any of the grain filling traits. General combining ability effects for grain filling rate, duration, and kernel weight were much larger than specific combining ability effects. Additive gene action made the major contribution to the inheritance of the grain filling traits. However, dominance effects appeared also to be involved in the genetic control of grain filling duration and kernel weight. Narrow sense heritability estimates were high for all three grain filling traits. Results indicated that early generation selection for both duration and rate of grain fill should be effective in these populations. Rate, but not duration of grain fill was closely associated with kernel weight. There was an inverse relationship between duration and rate of grain filling. Kernel protein percentage was positively associated with duration, but negatively related to rate of the grain filling. Results suggest that starch and protein accumulations in the kernel are two highly independent processes and may not necessarily compete for assimilates or energy. It may be necessary under the environments of this study to increase the duration of the grain fill to obtain high protein content with acceptable grain yield. / Graduation date: 1993

A negative relation between grain protein content and grain yield is frequently observed in wheat (Triticum aestivum L. em Thell) i.e. as grain yield increases, grain protein decreases. It has been suggested that the inverse relation between grain yield and protein is in part the result of developing high yielding semi-dwarf wheat cultivars with an increased harvest index. This investigation was undertaken to determine the nature of the possible association of grain yield and protein content as influenced by harvest index, biological yield, plant height and kernel weight in winter wheat populations grown in Oregon. Progenies derived from three crosses of winter wheat were solid-planted in two environments during two seasons. Phenotypic correlations showed a moderate negative association of grain protein content with both grain yield and harvest index. The magnitude of the genetic correlations suggested the presence of genetic relationships among these traits. Selection for harvest index among these crosses could cause a correlated reduction of grain protein content. To investigate if the relationships between grain protein content and selected plant growth traits were similar when grown under space-planted and solid seeded stands, progenies of two winter wheat crosses were evaluated during two seasons. Performance for grain yield and grain protein content was different under contrasting sowing densities as values were not correlated between sowing densities. This indicates the need to evaluate these traits in solid-seeded stands. Harvest index, as well as plant height and heading date, could be effectively selected under space-planted or solid seeded conditions. Associations among traits were reliably estimated in space-planted stands. To evaluate the effect on grain protein content when grain yield and harvest index are modified, the plant growth regulator Paclobutrazol was applied to selected winter wheat genotypes under field and greenhouse conditions. Paclobutrazol increased grain yield and harvest index values of all genotypes in the greenhouse, while only some genotypes improved these traits under field conditions. Grain protein content, however, remained unchanged. Higher grain yields were obtained in both greenhouse and field experiments. / Graduation date: 1991

Doctor of Philosophy / Genetics Interdepartmental Program / Allan K. Fritz / Globally, wheat (Triticum aestivum L.) is the second most widely grown cereal grain and is primarily used as a food crop. To meet the demands for human consumption, cultivars must possess suitable end-use quality for release and acceptability. However, breeding for quality traits is often considered a secondary goal, largely due to amount of seed needed and overall expense of such testing. Without testing and selection, many undesirable materials tend to be advanced. Here we demonstrate two methods, mega-genome-wide association mapping and genomic selection, to enhance selection accuracy for quality traits in the CIMMYT bread wheat breeding program. The methods were developed using high-density SNPs detected from genotyping-by-sequencing and processing and end-use quality evaluations from unbalanced yield trial entries (n = 4,095) during 2009 to 2014, at Ciudad Obregon, Sonora, Mexico. Genome-wide association mapping, with covariates for population structure and kinship, was applied for each trait to each site-year individually and results were combined across years in a mega-analysis using an inverse variance, fixed effect model in JMP-Genomics. This method presents a new way to detect genes of interest within a breeding program and develop markers for selection of these traits, which can then be used in earlier generations. Genomic selection prediction models were developed using ridge regression, Gaussian kernel, partial least squares, elastic net, and random forest models in R. With these predictions genomic selection (GS) can be applied at earlier stages and undesirable materials culled before implementing expensive yield and quality screenings. In general, prediction accuracy increased over time as more data was available to train the model. Based on these prediction accuracies, we conclude that genomic selection can be a useful tool to facilitate earlier generation selection for end-use quality in CIMMYT bread wheat breeding. Genomic selection was conducted for processing and end-use quality traits in the Kansas hard red winter wheat breeding unit. Genomic predictions demonstrate increases in accuracy with added data over time. These data demonstrate that current genomic selection models will need more data to continue improvement in prediction accuracy.

Orientador : Ahmed A. El-Dash / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos e Agricola / Made available in DSpace on 2018-07-14T06:28:19Z (GMT). No. of bitstreams: 1 Campos_MarceloSilveira_M.pdf: 5994208 bytes, checksum: 36583c78e90eec344b83a26e481259e1 (MD5) Previous issue date: 1985 / Resumo: A presente pesquisa teve por objetivo estudar a viabilidade tecnológica do uso de microondas no tratamento de trigo, visando a inativação de alfa-amilase e avaliação dos efeitos provocados por esse tipo de tratamento sobre a qualidade tecnológica da farinha. O trigo brasileiro (variedade BH 1146) sofreu um processo de maceração controlado, em água corrente à 300C, de tal forma a apresentar um elevado nível de atividade de alfa-amilase,uma condição requerida para esta pesquisa.O trigo, após maceração e secagem (400C), foi então exposto a energia de microondas variando o tempo e umidade no tratamento. As umidades qsqdas foram de 15, 18 e 21% enquanto que o tempo foi de 180, 270 e 360 segundos de irradiação. Diversos parâmetros que afetam a qualidade tecnológica foram estudadas de maneira a se estabelecer as condições favoráveis do processamento.Assim, foi estudado os efeitos da irradiação do trigo sobre as característicasdas propriedades de mistura,pasta, extensão, fermentação, cozimento da massa e na qualidade tecnológica global da farinha. A atividade de alfa-amilase foi reduzida, refletida pelo 10 aumento de viscosidade máxima com o incremento do tempo e umidade de tratamento. As amostras de trigo irradiadas por 180 segundos an todos os níveis de umidade pesquisados, apresentaram um aumento no tempo de desenvolvimento, estabilidade e tempo de saída enquanto que, índice de tolerância mecânica foi reduzido, indicando a formação de uma massa mais estável e tolerante à mistura. As amostras de trigo irradiadas por 180 segundos emto dos os níveis de umidade pesquisados e por 270 segundos à.15% de umidade apresentavam um aumento na energia total necessária para esticar a massa até o ponto de ruptura, acompanhado por um decréscimo na extensibilidade e um aumento na resistência à extensão, juntamente com um aumento do número proporcional indicando um aumento de ligações na rede de proteínas do glúten com conseqüente melhora na qualidade das farinhas. A irradiação do trigo com microondas por 180 segundos à 15,18 e 21% de umidade e por 270 segundos à 15% de umidade resultou numa melhora da qualidade do pão. Essas amostras além de mostrarem acréscimos-de 3 a 20%, em relação ao padrão, na contagem total dos pontos de qualidade do pão, atingiram ainda, valores característicos de uma farinha com boa qualidade de panificação. Por outro lado, uma excessiva irradiação do trigo reduziu todos os parâmetros de qualidade do pão, resultando num produto muito inferior a aquele produzido com o controle / Abstract: This study aimed to investigate the feasibility of using microwave technology in the treatment of wheat, aimed at the inactivation of alpha-amylase and evaluation of the effects caused by this type of treatment on the technological quality of flour. The Brazilian wheat (variety BH 1146) has undergone a process of controlled maceration, in running water to 300C in such a way that shows a high level of activity of alpha-amylase, a condition required for this search query wheat, after soaking and drying (400C), was then exposed to microwave energy of varying the time and humidity in the treatment. The humidity qsqdas were 15, 18 and 21% while the time was 180, 270 and 360 seconds of irradiation. Several parameters that affect the technological quality have been studied so as to establish whether the favorable conditions of processamento.Assim, has been studied the effects of irradiation of wheat on característicasdas properties of the mixture, folder, extension, fermentation, cooking masses and the technological quality Overall the meal. The activity of alpha-amylase was reduced, reflected by the 10 highest increase of viscosity with the increase in humidity and time of treatment. Samples of wheat irradiated for 180 seconds an all levels of humidity surveyed, showed an increase in development time, stability and time of departure while, mechanical index of tolerance was low, indicating the formation of a mass more stable and tolerant to mixture. Samples of wheat irradiated for 180 seconds emto of the levels of moisture and searched for 270 seconds A.15% moisture showed an increase in total energy needed to stretch the mass to the point of collapse, accompanied by a decrease in extensibility and a increase resistance to extension, along with an increase in the proportion indicating an increasing number of links in the network of gluten proteins with the consequent improvement in the quality of flour. The irradiation of wheat with microwave for 180 seconds to 15.18 and 21% moisture and 270 seconds for the 15% moisture resulted in an improvement in the quality of bread. These samples show increases in addition to the 3-to 20% on the standard, in the total count of points of quality of bread, yet, values characteristic of a good quality of flour with baking. On the other hand, an excessive irradiation of wheat reduced all the quality parameters of bread, resulting in a product much less than that produced with the control / Mestrado / Tecnologia de Alimentos / Mestre em Tecnologia de Alimentos

Call number: LD2668 .T4 1984 U62 / Master of Science