Thesis (Ph. D.)--University of Adelaide, Dept. of Plant Science, 1999. / Includes bibliographical references (leaves 203-212).

Durum wheat cultivars for North-Eastern Oregon have to be competitive in terms of their yield potential with soft white winter wheat cultivars and meet strict quality requirements of the milling industry. Combining the high yield potential of fall planted durum wheat cultivars which have an acceptable level of winter hardiness with the good quality characteristics of the spring types through winter by spring crosses is believed to be an appropriate strategy. However, to be efficient, quality traits of the breeding lines and the nature of their inheritance must be evaluated early in the breeding process. The primary objective of this study was to investigate the nature of genetic variability involving two main quality traits, namely gluten strength and carotenoid pigment content. These traits are measured by the SDS sedimentation test and by spectrophotometric analysis of pigment extracts, respectively. Total genetic variability involving grain yield, kernel weight and protein content was also studied. Combining ability analysis of a 4x4 diallel cross using two winter and two spring parents was performed according to Griffing's (1956) Model 1, method 1. Both additive and non additive type gene action controlled all traits studied. Non additive type gene action was particularly important for grain yield and kernel weight suggesting that selection for these traits should be delayed until later generations (F5 or F6). Protein and pigment content were controlled primarily by genes functioning in an additive manner although they are also influenced by significant non additive type gene action. Reciprocal effects were significant for pigment content suggesting that some maternal effect might be involved. The predominance of additive type gene action for sedimentation volume suggests that this trait can be used to screen early generation material (F2, F3) for gluten strength. F2 populations generated from the diallel cross were compared in terms of their genetic variances, potential transgressive segregation and were used to investigate the possible associations between the traits measured. Winter by spring crosses were usually characterized by an enhanced genetic variability for yield and gluten strength. Transgressive segregation for sedimentation volume was present in these crosses. Protein content was negatively associated with grain yield. No relationship between gluten strength and grain yield was observed. Gluten strength did not appear to be associated with total protein content of the grain. Sedimentation volume varied greatly, even in populations with low variability in protein content. Consequently, selection on the basis of sedimentation volume per se would not be result in selecting inadvertently agronomically unsuitable types. / Graduation date: 1991

Fungi contribute to key processes in the sustainable function of terrestrial ecosystems including nutrient cycling and transport of water to plants. However, some fungal species are of interest because their infection of a susceptible host crop results in diseases negatively affecting food supply and quality. These diseases are expected to be influenced by rotation crops which could impact the development of plant pathogens and their genetic biodiversity. The objectives of this study were to assess the biodiversity of fungal pathogens in durum wheat, to identify the naturally occurring fungi that could have biocontrol potential, and to define the impact of crop rotation with non-cereal crops on fungal populations in durum wheat. For this purpose, in 2004, 2005, and 2006, soil and durum wheat plant samples were collected after preceding crops of <i>Pisum sativum</i> L. (pea), <i>Lens culinaris</i> Medik (lentil), <i>Cicer arietinum</i> L. (chickpea), <i>Brassica napus</i> L. (canola) and <i>Triticum turgidum</i> L. (durum) in a long term experimental site in Swift Current, Sakatchewan. Samples were analyzed using a combination of traditional cultivation techniques and polymerase chain reaction (PCR), sequencing, and denaturing gradient gel electrophoresis (DGGE) techniques. <p>Fusarium species, known as the causal agent of Fusarium head blight (FHB) and Fusarium damaged kernels (FDK) were among the most ubiquitous and abundant in durum tissues. The most prevalent of all Fusarium at the study site were <i>F. avenaceum, F. reticulatum</i>, and <i>F. tricinctum</i>. Other recovered potential fungal pathogens belonged to the genera Bipolaris, Phaeosphaeria, Pyrenophora, Cladosporium, Epicoccum, Alternaria, Cladosporium, Arthrinium, Nigrospora, and Microdochium. Principal component analysis revealed negative correlations between Acremonium, Chaetomium, Penicillium, and pathogenic Fusarium, Bipolaris, Pyrenophora, and Alternaria. These isolates could be antagonistic, and their potential as biocontrol agents against pathogens colonizing durum wheat in the semiarid Saskatchewan should be assessed.<p>Crop rotation had a limited impact on the abundance of fungal pathogens. Fusarium torulosum was less abundant in durum following canola while Bipolaris sorokiniana was less abundant in durum following pea. Even if no single crop rotation reduced significantly the prevalence of F. avenaceum in durum wheat, results suggest that a successful control of this important pathogen requires an integrated approach using diversified rotations.

Fungi contribute to key processes in the sustainable function of terrestrial ecosystems including nutrient cycling and transport of water to plants. However, some fungal species are of interest because their infection of a susceptible host crop results in diseases negatively affecting food supply and quality. These diseases are expected to be influenced by rotation crops which could impact the development of plant pathogens and their genetic biodiversity. The objectives of this study were to assess the biodiversity of fungal pathogens in durum wheat, to identify the naturally occurring fungi that could have biocontrol potential, and to define the impact of crop rotation with non-cereal crops on fungal populations in durum wheat. For this purpose, in 2004, 2005, and 2006, soil and durum wheat plant samples were collected after preceding crops of <i>Pisum sativum</i> L. (pea), <i>Lens culinaris</i> Medik (lentil), <i>Cicer arietinum</i> L. (chickpea), <i>Brassica napus</i> L. (canola) and <i>Triticum turgidum</i> L. (durum) in a long term experimental site in Swift Current, Sakatchewan. Samples were analyzed using a combination of traditional cultivation techniques and polymerase chain reaction (PCR), sequencing, and denaturing gradient gel electrophoresis (DGGE) techniques. <p>Fusarium species, known as the causal agent of Fusarium head blight (FHB) and Fusarium damaged kernels (FDK) were among the most ubiquitous and abundant in durum tissues. The most prevalent of all Fusarium at the study site were <i>F. avenaceum, F. reticulatum</i>, and <i>F. tricinctum</i>. Other recovered potential fungal pathogens belonged to the genera Bipolaris, Phaeosphaeria, Pyrenophora, Cladosporium, Epicoccum, Alternaria, Cladosporium, Arthrinium, Nigrospora, and Microdochium. Principal component analysis revealed negative correlations between Acremonium, Chaetomium, Penicillium, and pathogenic Fusarium, Bipolaris, Pyrenophora, and Alternaria. These isolates could be antagonistic, and their potential as biocontrol agents against pathogens colonizing durum wheat in the semiarid Saskatchewan should be assessed.<p>Crop rotation had a limited impact on the abundance of fungal pathogens. Fusarium torulosum was less abundant in durum following canola while Bipolaris sorokiniana was less abundant in durum following pea. Even if no single crop rotation reduced significantly the prevalence of F. avenaceum in durum wheat, results suggest that a successful control of this important pathogen requires an integrated approach using diversified rotations.

No description available.

Typescript (photocopy) / Digitized by Kansas Correctional Industries

Durum wheat (<i>Triticum turgidum</i> L. var. durum, 2n = 4x = 28, AABB genomes) is used predominantly for semolina and pasta products, but there is increasing interest in using durum for bread-making to provide alternative markets during periods of overproduction. The goal of this study was to characterize the bread-making quality of durum wheat cultivars and emmer (<i>Triticum turgidum</i> L. var. dicoccum, 2n = 4x = 28) derived breeding lines derived from crosses of durum wheat with an Emmer land race 97Emmer19 from Iran. Emmer-derived breeding lines were evaluated along with three high quality bread wheat (<i>Triticum aestivum</i> L., 2n = 6x = 42, AABBDD genomes) cultivars and seven durum wheat cultivars across three environments in replicated yield trials in the 2005 and 2006 growing seasons. Four 1AS.1AL-1DL translocation lines which carry the Glu-D1d allele [high molecular weight glutenin subunit (HMW-GS) pair 1Dx5+1Dy10] from chromosome 1D of bread wheat were also evaluated. In general, durum wheat cultivars with elevated gluten strength and/or increased dough extensibility were noted to have higher loaf volume (LV) than those with weaker gluten. The 1AS.1AL-1DL translocation line L252 carrying the LMW-1 banding pattern had better dough mixing stability and LV than the translocation lines with the LMW-2 banding pattern. The 1AS.1AL-1DL translocation lines had higher grain protein concentrations (GPC), but the lowest loaf volumes of all the lines tested. These translocation lines also exhibited unappealing external loaf quality (loaf shape and appearance) and poor internal loaf quality (crumb structure). Variation in bread-making quality attributes were observed among durum genotypes. 97Emmer19 exhibited higher LV than all the durum wheats evaluated and approached the loaf volume achieved with the bread wheat cultivar AC Superb. Breeding lines derived from crosses of 97Emmer19 to strong gluten durum cultivars (WB881 or AC Navigator) had higher LV than those of the durum checks. 97Emmer19 carried Glu-A1a* (HMW-GS 1Ax1) and the progeny carrying that allele generally exhibited higher loaf volumes. Durum wheat genotypes expressing the Glu-B1d (HMW-GS pair Bx6+By8) allele exhibited better overall bread-making quality compared with those expressing the Glu-B1b (HMW-GS pair Bx7+By8) allele. The durum cultivar Arcola and the emmer-derived breeding line 2000EB4, showed higher alveograph extensibility (L) values than did the bread wheat check AC Barrie. The durum wheat genotypes (with the exception of Stewart-63) and emmer-derived breeding lines exhibited better dough extensibility than the USDA-ARS 1AS.1AL-1DL translocation lines. These results indicate that there is potential to select for genotypes with improved baking quality in durum breeding programs.

Durum wheat (<i>Triticum turgidum</i> L. var. durum, 2n = 4x = 28, AABB genomes) is used predominantly for semolina and pasta products, but there is increasing interest in using durum for bread-making to provide alternative markets during periods of overproduction. The goal of this study was to characterize the bread-making quality of durum wheat cultivars and emmer (<i>Triticum turgidum</i> L. var. dicoccum, 2n = 4x = 28) derived breeding lines derived from crosses of durum wheat with an Emmer land race 97Emmer19 from Iran. Emmer-derived breeding lines were evaluated along with three high quality bread wheat (<i>Triticum aestivum</i> L., 2n = 6x = 42, AABBDD genomes) cultivars and seven durum wheat cultivars across three environments in replicated yield trials in the 2005 and 2006 growing seasons. Four 1AS.1AL-1DL translocation lines which carry the Glu-D1d allele [high molecular weight glutenin subunit (HMW-GS) pair 1Dx5+1Dy10] from chromosome 1D of bread wheat were also evaluated. In general, durum wheat cultivars with elevated gluten strength and/or increased dough extensibility were noted to have higher loaf volume (LV) than those with weaker gluten. The 1AS.1AL-1DL translocation line L252 carrying the LMW-1 banding pattern had better dough mixing stability and LV than the translocation lines with the LMW-2 banding pattern. The 1AS.1AL-1DL translocation lines had higher grain protein concentrations (GPC), but the lowest loaf volumes of all the lines tested. These translocation lines also exhibited unappealing external loaf quality (loaf shape and appearance) and poor internal loaf quality (crumb structure). Variation in bread-making quality attributes were observed among durum genotypes. 97Emmer19 exhibited higher LV than all the durum wheats evaluated and approached the loaf volume achieved with the bread wheat cultivar AC Superb. Breeding lines derived from crosses of 97Emmer19 to strong gluten durum cultivars (WB881 or AC Navigator) had higher LV than those of the durum checks. 97Emmer19 carried Glu-A1a* (HMW-GS 1Ax1) and the progeny carrying that allele generally exhibited higher loaf volumes. Durum wheat genotypes expressing the Glu-B1d (HMW-GS pair Bx6+By8) allele exhibited better overall bread-making quality compared with those expressing the Glu-B1b (HMW-GS pair Bx7+By8) allele. The durum cultivar Arcola and the emmer-derived breeding line 2000EB4, showed higher alveograph extensibility (L) values than did the bread wheat check AC Barrie. The durum wheat genotypes (with the exception of Stewart-63) and emmer-derived breeding lines exhibited better dough extensibility than the USDA-ARS 1AS.1AL-1DL translocation lines. These results indicate that there is potential to select for genotypes with improved baking quality in durum breeding programs.

No description available.

Orientador: Yoon Kil Chang / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T21:12:19Z (GMT). No. of bitstreams: 1 Depieri_Matheus_M.pdf: 2073635 bytes, checksum: 4b24da7da4e4941973fd7a1a74858c5e (MD5) Previous issue date: 2004 / Resumo: O presente trabalho analisou a produção de pastas instantâneas feitas a partir de dois tipos de matérias-primas, a farinha de trigo comum e a semolina de trigo durum, utilizando o processo de extrusão termoplástica. O objetivo principal do trabalho foi comparar a qualidade dos dois tipos de pastas obtidos, já que pelo processo convencional de produção de massas alimentícias, a matéria-prima mais usada e que garante melhor qualidade às pastas é a semolina de trigo durum, que, por outro lado, apresenta um maior custo. Procurou-se, através do processo de extrusão, obter produtos de características semelhantes, mesmo usando uma matéria-prima de qualidade inferior e custo mais baixo, que é o caso da farinha de trigo comum. Para isso foi utilizado um extrusor termoplástico de rosca simples Brabender mod. 1014/2, seguindo um planejamento experimental do tipo composto central rotacional com 3 variáveis independentes, a temperatura na 2ª zona do extrusor (x1), umidade da mistura inicial (x2) e teor de emulsificante na mistura inicial (x3). Foram analisadas, além da composição centesimal e características reológicas das matérias-primas, as seguintes respostas para as pastas instantâneas obtidas: umidade, cor, tempo ótimo de cozimento, perda de sólidos na água de cozimento, ganho de peso, ganho de volume e textura (força máxima de ruptura e trabalho de ruptura). Foram obtidos os respectivos modelos matemáticos e as superfícies de resposta de cada parâmetro. Além disso, algumas amostras foram submetidas a testes de calorimetria de varredura diferencial, microscopia eletrônica de varredura e teste de difração de raios-X, a fim de se determinar, principalmente, o grau de gelatinização do amido nas amostras em cada condição de processo. As pastas instantâneas de melhor qualidade obtidas apresentaram tempo ótimo de cozimento de 1,5-2,0 minutos, perda mínima de sólidos na água de cozimento (1,5%), força de ruptura de 15-20 g e trabalho de ruptura em torno de 50 g. No caso da semolina de trigo durum, as condições de processo para se obter tais características seriam temperatura de 115°C, umidade da mistura inicial de 26% e teor de emulsificante de 1,0%. Já no caso da farinha de trigo comum, as condições de processo incluiriam temperatura de 105-110°C, umidade 24-25% e maior teor de emulsificante (1,15-1,5%). Micrografias, juntamente com análises de calorimetria diferencial de varredura (DSC) e difração de raios-X, evidenciaram um alto grau de gelatinização do amido e desnaturação protéica das amostras de pasta instantânea obtidas sob diferentes condições de processamento. Também foi verificada a formação de complexos amilose-emulsificante, apresentando forte influência nas características de cozimento e qualidade das pastas obtidas / Abstract: This present work analyzed the production of instantaneous pasta made from two different types of raw materials, flour of common wheat and semolina of durum wheat, using a thermoplastic extrusion process. The main purpose was to compare the quality of the two types of pasta, because through conventional process, pastas are usually made from semolina of durum wheat that guarantees a better quality but, on the other hand, shows a higher cost than other varieties of wheat. It had been tried, through cooking extrusion process, to obtain products with similar characteristics, even using a poorer quality and lower cost raw material, as the flour of common wheat. So, it was used a Brabender single screw extruder, model 1014/2, following a rotatable central-composite design with 3 independent variables: the temperature in the 2nd zone of the extruder (x1), moisture of initial mixture (x2) and rate of emulsifier in the initial mixture (x3). Besides the analysis of composition and rheological characteristics of raw materials, it had been determined the following answers for obtained pastas: moisture content, color parameters, cooking time, cooking loss, weight and volume gain after rehydration, and texture (including maximum force of rupture and work of rupture). It was obtained the mathematic models and surface response for each answer. Some experiments underwent to tests of differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and X-ray diffraction to determine, mainly, the extent of gelatinization in pastas for each different process conditions. High quality obtained pastas presented cooking time of 1,5-2,0 minutes, minimum cooking loss (1,5%), force of rupture of 15-20 g and work of rupture around 50 g. In the case of durum wheat semolina, the conditions of process to get such characteristics were 115°C, 26% of initial moisture and 1,0% of emulsifier. No longer case of common wheat flour, the process conditions included temperature of 105-110°C, moisture 24-25% and high percentage of emulsifier (1,15-1,5%). Micrographs, with DSC and X-ray diffraction analysis, showed a high level of starch gelatinization and protein denaturation in pastas produced under different process conditions. It was also verified the formation of amylose-emulsifier complexes, those strongly influenced the pasta quality and cooking characteristics / Mestrado / Mestre em Tecnologia de Alimentos