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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Manganese efficiency in durum wheat (Triticum targidum L. var durum) / by Hossein Khabaz Saberi.

Saberi, Hossein Khabaz January 1999 (has links)
Bibliography: leaves 203-212. / xiii, 212 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This study investigated the genetic diversity for tolerance of durum wheat (Triticum turgidum L. var durum) to micronutrient deficient soils with an emphasis on manganese. 69 genotypes were studied under field conditions at Marion Bay (Lower Eyre Peninsula) and Coonalpyn. Durum genotypes, notably Stojocri, were identified as having higher tolerance than commerical durum varieties. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1999
32

Manganese efficiency in durum wheat (Triticum targidum L. var durum)

Saberi, Hossein Khabaz. January 1999 (has links) (PDF)
Bibliography: leaves 203-212. This study investigated the genetic diversity for tolerance of durum wheat (Triticum turgidum L. var durum) to micronutrient deficient soils with an emphasis on manganese. 69 genotypes were studied under field conditions at Marion Bay (Lower Eyre Peninsula) and Coonalpyn. Durum genotypes, notably Stojocri, were identified as having higher tolerance than commerical durum varieties.
33

Effect Of Different Wheat Varieties On Pasta Quality

Bozkurt, Murat 01 October 2012 (has links) (PDF)
There are about 40 durum wheat varieties registered in Turkey. Around 10 varieties are being commonly cultivated. Amanos 97, &Ccedil / esit 1252, Ege 88, Firat 93, Fuatbey 2000, Burgos, Kiziltan 91, Sari&ccedil / anak 98, Svevo and Zenith durum wheat varieties were used in this study. Semolina and pasta have been produced in an industrial plant under constant process conditions from these varieties. In general, pasta quality is determined by three main factors, the raw materials, the production recipe and the production process. In this study, the production recipe and the production process were fixed and only durum wheat varieties were variable. So, the effects coming from the production recipe and the production process on pasta quality were eliminated. Physical, chemical and sensory properties of these pasta were determined and the effect of different durum wheat varieties on pasta quality has been investigated to give a clear idea to the Turkish pasta industry about the most commonly grown durum wheat varieties in Turkey, hoping that Turkish pasta in domestic and international Markets will continue to grow with the help of clear understanding about the quality characteristics of the durum wheat they are using. v The important criteria of acceptability of pasta products is its cooking quality and cooking quality of pasta products is of importance to consumers and also to wheat producers, breeders and manufacturers. The pasta samples produced from Svevo, Zenith and Firat 93 varieties got the higher scores than others in pasta cooking quality while those produced from Sari&ccedil / anak 98, &Ccedil / esit 1252, Kiziltan 91, and Fuatbey 2000 durum wheat were evaluated as relatively low. The main reasons of cooking quality differences can be interpreted as a result of the difference in protein quantity and quality of the varieties. The bright yellow color of pasta products, rather than cooking behavior taste, is reported to be one of the most important considerations in assessing durum wheat quality. In this study, the pasta samples produced from Svevo, Zenith and Burgos varieties got the higher scores than others in pasta color (yellowness) while that produced from Firat 93 had the lowest yellow color. The main reasons of yellow color differences can be interpreted as a result of the differences in carotenoid pigments, lipoxygenase and peroxidase enzymes contents of the varieties.
34

A study of the genetics and physiological basis of grain protein concentration in Durum wheat (<i>Triticum turgidum</i> L. var. <i>durum</i>)

Suprayogi, Yogi 11 December 2009
In durum wheat (<i>Triticum turgidum</i> L. var <i>durum</i>), grain protein concentration (GPC) and gluten quality are among the important factors influencing pasta-making quality. Semolina with high protein content produces pasta with increased tolerance to overcooking and greater cooked firmness. However, genetic improvement of GPC is difficult largely because of its negative correlation with grain yield, and a strong genotype x environment interaction. Therefore, identification of quantitative trait loci (QTL) for high GPC and the associated markers is a priority to enhance selection efficiency in breeding durum wheat for elevated GPC. At a physiological level, GPC is influenced by several factors including nitrogen remobilization from vegetative organs and direct post-anthesis nitrogen uptake (NUP) from the soil. Understanding the relationship between elevated GPC and nitrogen remobilization, and post-anthesis NUP will enable durum wheat breeders to develop varieties that not only produce high yield and high GPC, but also exhibit better nitrogen use efficiency. The objectives of this study were: (1) to identify and validate QTL for elevated GPC in two durum wheat populations; and (2) to determine if elevated GPC is due to more efficient nitrogen remobilization and/or greater post-anthesis NUP. A genetic map was constructed with SSR and DArT® markers in a doubled haploid population from the cross Strongfield x DT695, and GPC data were collected in replicated trials in six Canadian environments from 2002 to 2005. Two stable QTL for high GPC, QGpc.usw-B3 on chromosome 2B and QGpc.usw-A3 on 7A, were identified. Strongfield, the high GPC parent, contributed the alleles for elevated GPC at both QTL. These two QTL were not associated with variation in grain weight (seed size) or grain yield. QGpc.usw-A3 was validated in a second Strongfield-derived population as that QTL was significant in all six testing environments. Averaged over five locations, selection for QGpc.usw-A3 resulted in a +0.4% to +1.0% increase in GPC, with only small effects on yield in most environments. A physiological study of grain protein accumulation revealed that regardless of the growing condition, nitrogen remobilization was the major contributor for grain nitrogen in durum genotypes evaluated, accounting for an average of 84.3% of total GPC. This study confirmed that introgression of Gpc-B1 into Langdon resulted in increased GPC, and this GPC increase was due to higher N remobilization. Strongfield expressed greater N remobilization than DT695 and the semi-dwarf cultivar Commander, but N remobilization was not the determining factor for Strongfields elevated GPC. Strongfield expressed greater post-anthesis NUP than DT695. Similarly, a selection of six high-GPC doubled haploid (DH) lines from the cross DT695 x Strongfield expressed significantly greater post-anthesis NUP than six low-GPC DH selections, supporting the hypothesis that elevated GPC in Strongfield is derived from greater post-anthesis NUP. All six high-GPC DH selections carried the Strongfield allele at QGpc.usw-A3, suggesting this QTL maybe associated with post-anthesis NUP.
35

A study of the genetics and physiological basis of grain protein concentration in Durum wheat (<i>Triticum turgidum</i> L. var. <i>durum</i>)

Suprayogi, Yogi 11 December 2009 (has links)
In durum wheat (<i>Triticum turgidum</i> L. var <i>durum</i>), grain protein concentration (GPC) and gluten quality are among the important factors influencing pasta-making quality. Semolina with high protein content produces pasta with increased tolerance to overcooking and greater cooked firmness. However, genetic improvement of GPC is difficult largely because of its negative correlation with grain yield, and a strong genotype x environment interaction. Therefore, identification of quantitative trait loci (QTL) for high GPC and the associated markers is a priority to enhance selection efficiency in breeding durum wheat for elevated GPC. At a physiological level, GPC is influenced by several factors including nitrogen remobilization from vegetative organs and direct post-anthesis nitrogen uptake (NUP) from the soil. Understanding the relationship between elevated GPC and nitrogen remobilization, and post-anthesis NUP will enable durum wheat breeders to develop varieties that not only produce high yield and high GPC, but also exhibit better nitrogen use efficiency. The objectives of this study were: (1) to identify and validate QTL for elevated GPC in two durum wheat populations; and (2) to determine if elevated GPC is due to more efficient nitrogen remobilization and/or greater post-anthesis NUP. A genetic map was constructed with SSR and DArT® markers in a doubled haploid population from the cross Strongfield x DT695, and GPC data were collected in replicated trials in six Canadian environments from 2002 to 2005. Two stable QTL for high GPC, QGpc.usw-B3 on chromosome 2B and QGpc.usw-A3 on 7A, were identified. Strongfield, the high GPC parent, contributed the alleles for elevated GPC at both QTL. These two QTL were not associated with variation in grain weight (seed size) or grain yield. QGpc.usw-A3 was validated in a second Strongfield-derived population as that QTL was significant in all six testing environments. Averaged over five locations, selection for QGpc.usw-A3 resulted in a +0.4% to +1.0% increase in GPC, with only small effects on yield in most environments. A physiological study of grain protein accumulation revealed that regardless of the growing condition, nitrogen remobilization was the major contributor for grain nitrogen in durum genotypes evaluated, accounting for an average of 84.3% of total GPC. This study confirmed that introgression of Gpc-B1 into Langdon resulted in increased GPC, and this GPC increase was due to higher N remobilization. Strongfield expressed greater N remobilization than DT695 and the semi-dwarf cultivar Commander, but N remobilization was not the determining factor for Strongfields elevated GPC. Strongfield expressed greater post-anthesis NUP than DT695. Similarly, a selection of six high-GPC doubled haploid (DH) lines from the cross DT695 x Strongfield expressed significantly greater post-anthesis NUP than six low-GPC DH selections, supporting the hypothesis that elevated GPC in Strongfield is derived from greater post-anthesis NUP. All six high-GPC DH selections carried the Strongfield allele at QGpc.usw-A3, suggesting this QTL maybe associated with post-anthesis NUP.
36

Manganese efficiency in durum wheat (Triticum targidum L. var durum) / by Hossein Khabaz Saberi.

Saberi, Hossein Khabaz January 1999 (has links)
Bibliography: leaves 203-212. / xiii, 212 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This study investigated the genetic diversity for tolerance of durum wheat (Triticum turgidum L. var durum) to micronutrient deficient soils with an emphasis on manganese. 69 genotypes were studied under field conditions at Marion Bay (Lower Eyre Peninsula) and Coonalpyn. Durum genotypes, notably Stojocri, were identified as having higher tolerance than commerical durum varieties. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1999
37

Formalisation et étude des explications dialectiques dans les bases de connaissances incohérentes / Formalizing and Studying Dialectical Explanations in Inconsistent Knowledge Bases

Arioua, Abdallah 17 October 2016 (has links)
Les bases de connaissances sont des bases de données déductives où la logique est utilisée pour représenter des connaissances de domaine sur des données existantes. Dans le cadre des règles existentielles, une base de connaissances est composée de deux couches : la couche de données qui représentent les connaissances factuelle et la couche ontologique qui incorpore des règles de déduction et des contraintes négatives. L’interrogation de données à l’aide des ontologies est la fonction de raisonnement principale dans ce contexte. Comme dans la logique classique, les contradictions posent un problème à l’interrogation car « d'une contradiction, on peut déduire ce qu'on veut (ex falso quodlibet) ».Récemment, des approches d’interrogation tolérantes aux incohérences ont été proposées pour faire face à ce problème dans le cadre des règles existentielles. Elles déploient des stratégies dites de réparation pour restaurer la cohérence. Cependant, ces approches sont parfois inintelligibles et peu intuitives pour l'utilisateur car elles mettent souvent en œuvre des stratégies de réparation complexes. Ce manque de compréhension peut réduire l’utilisabilité de ces approches car elles réduisent la confiance entre l'utilisateur et les systèmes qui les utilisent. Par conséquent, la problématique de recherche que nous considérons est comment rendre intelligible à l’utilisateur l’interrogation tolérantes aux incohérences. Pour répondre à cette question de recherche, nous proposons d’utiliser deux formes d’explication pour faciliter la compréhension des réponses retournées par une interrogation tolérante aux incohérences. La première est dite de niveau méta et la seconde de niveau objet. Ces deux types d’explication prennent la forme d'un dialogue entre l'utilisateur et le raisonneur au sujet des déductions retournées comme réponses à une requête donnée. Nous étudions ces explications dans le double cadre de l'argumentation fondée sur la logique et de la dialectique formelle, comme nous étudions leurs propriétés et leurs impacts sur les utilisateurs en termes de compréhension des résultats. / Knowledge bases are deductive databases where the machinery of logic is used to represent domain-specific and general-purpose knowledge over existing data. In the existential rules framework a knowledge base is composed of two layers: the data layer which represents the factual knowledge, and the ontological layer that incorporates rules of deduction and negative constraints. The main reasoning service in such framework is answering queries over the data layer by means of the ontological layer. As in classical logic, contradictions trivialize query answering since everything follows from a contradiction (ex falso quodlibet). Recently, inconsistency-tolerant approaches have been proposed to cope with such problem in the existential rules framework. They deploy repairing strategies on the knowledge base to restore consistency and overcome the problem of trivialization. However, these approaches are sometimes unintelligible and not straightforward for the end-user as they implement complex repairing strategies. This would jeopardize the trust relation between the user and the knowledge-based system. In this thesis we answer the research question: ``How do we make query answering intelligible to the end-user in presence of inconsistency?''. The answer that the thesis is built around is ``We use explanations to facilitate the understanding of query answering''. We propose meta-level and object-level dialectical explanations that take the form of a dialogue between the user and the reasoner about the entailment of a given query. We study these explanations in the framework of logic-based argumentation and dialectics and we study their properties and their impact on users.
38

Characterization Of Yellow Rust And Stem Rust Resistant And Sensitive Durum Wheat Lines At Molecular Level By Using Biophysical Methods

Kansu, Cigdem 01 September 2011 (has links) (PDF)
Stem rust and Yellow rust diseases are the two major wheat fungal diseases causing considerable yield losses in Turkey and all around the world. There are studies which are carried out to identify and utilize resistance sources in order to obtain resistant lines of wheat. However, virulent pathotypes are continuously being important threats to wheat production and yield. For that reason, new approaches for rapid identification are needed. The aim of this study was to investigate and to understand the structural and functional differences between the resistant and sensitive durum wheat cultivars to the plant fungal diseases of stem and yellow (stripe) rusts. To aim this, forty durum wheat recombinant inbred lines (RILs), which were previously determined to be resistant or sensitive to stem and yellow rust diseases, were investigated by the noninvasive Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) Spectroscopy. Also, classification of the resistant and sensitive lines depending on the structural and functional differences has been attempted. The FTIR spectra for stem rust disease showed that, resistant durum wheat lines had a significant increase in the population of unsaturation in acyl chains of lipid molecules, an increase in lipid and in total protein content and also an increase in carboxylic acids and alcohols. For yellow rust disease, resistant lines had a significant increase in hydrogen bonding and they had also a more ordered membrane structure. In Principal Component Analysis for stem rust disease, according to 3700-650 cm-1 region, amide III band (1213-1273 cm-1 region) and C-H stretching region (3020- 2800 cm-1), the resistant and sensitive groups were separated successfully. For yellow rust disease, according to 3700-650 cm-1 region, Amide A and Amide III bands, the resistant and sensitive lines were grouped distinctly. FTIR spectroscopy provides a useful approach to determine the differences in molecular structure of durum wheat RILs regarding resistance of lines to fungal diseases. However, further research is still needed to ensure if the structural and functional differences in biomolecules of the samples could be used as molecular markers for discrimination of rust resistant materials from rust sensitive ones.
39

Adéquation des blés durs aux opérations de transformations technologiques : semoulerie et pastification / Adaptation of the durum wheat grain processes : milling and pasta making

Joubert, Marianne 13 December 2017 (has links)
Le blé dur est la matière première de base pour la production de semoules et de pâtes. Les origines des rendements semouliers et qualité des pâtes sont multifactorielles. Or, il n’existe pas aujourd’hui d’outil global permettant de prédire les valeurs semoulières et pastières des blés durs sur la base des caractéristiques physiques et biochimiques des grains. Le travail mené dans le cadre de cette thèse s’attache à objectiver le potentiel semoulier et pastier de lots de grains, issus de pratiques culturales innovantes, dans une optique d’améliorer la durabilité de la filière blé dur.Des lots de grains de blé dur ont été caractérisés et leurs variabilités mises en relation avec les différents itinéraires techniques agricoles dont ils sont issus. L’impact de la qualité des récoltes sur le comportement à la mouture des lots, ainsi que sur l’aspect des pâtes sèches et la texture des pâtes cuites a été étudié. Les teneurs en protéines, en cendres et la granulométrie de la semoule ont été identifiées comme des facteurs influençant la qualité des pâtes. Une démarche « plan d’expériences » a été développée pour évaluer l’impact d’un seul facteur, indépendamment des deux autres, sur la qualité des pâtes. L’efficience des procédés de transformation en fonction de la variabilité de la matière première a également été appréciée. En particulier, l’impact des caractéristiques des grains de blé dur sur les énergies nécessaires à la mouture, les liens entre composition de la semoule et comportement à l’extrusion et l’efficacité de différents diagrammes de séchage sur la qualité des pâtes en fonction de leurs compositions, ont été analysés. Une étude a été également menée sur l’état de polymérisation des protéines au cours de la fabrication des pâtes. Enfin, cette thèse a permis la constitution d’une base de données qui contribuera à la prédiction de la qualité des semoules et pâtes en fonctions des caractéristiques physiques et biochimiques des blés durs. / Durum wheat is the best raw material to process semolina and pasta. The origins of high semolina yield and the good pasta quality are multifactorial. However, there is currently no tool predicting milling and pasta making results based on physical and biochemical characteristics of durum wheat grains. The work carried out in this PhD thesis attempts to objectify the technological value of durum wheat samples, grown with innovative technical practices in order to improve sustainability of the French durum wheat chain.Durum wheat samples batches were characterised and their variability was related to the different agricultural technical routes used. The impact of the grain quality on the milling behaviour of the samples, as well as the appearance of the dry pasta and the texture of the cooked pasta was studied. Protein, ash contents and semolina particle size distribution were identified as factors influencing pasta quality. An “experimental design” approach was developed to obtain a non-distorted estimate of how each variable impacts the quality of pasta, independently of the other two variables. Efficiency of the semolina milling and pasta making processes depending on the variability of the raw material was also assessed. Especially, the impact of durum wheat grains characteristics on the energies required for milling, the relationship between semolina composition and extrusion behaviour and the effectiveness of different drying diagrams on the quality of the pasta based on their compositions were analysed. A study on the protein polymerisation state during the pasta making process was also conducted. Finally, this PhD thesis has contributed to the development of a database that will predict semolina and pasta quality depending on physical and biochemical characteristics of durum wheat.
40

Genetic characterization of Fusarium head blight resistance in durum wheat / Caractérisation des déterminants génétiques de la résistance à la fusariose chez le blé dur

Prat, Noémie 28 October 2016 (has links)
La fusariose de l’épi est une maladie fongique qui touche toutes les cultures de céréales à paille à travers le monde entrainant des baisses de rendements et de la qualité des grains. La fusariose pose également un problème pour la sécurité alimentaire lié à la contamination des grains infectés par des mycotoxines. Le développement de variétés résistantes est considéré comme la méthode la plus efficace et la plus durable pour réduire les dommages causés par la maladie et pour limiter la contamination par les mycotoxines. L’amélioration de la résistance à la fusariose chez le blé dur (Triticum durum Desf.) demeure un défi du fait de son extrême sensibilité à la maladie et de la faible variabilité génétique disponible pour ce caractère. L’objectif principal de cette thèse a été d’évaluer l’effet de Fhb1, le QTL majeur de résistance à la fusariose chez le blé tendre (Triticum aestivumL.), au sein de fonds génétiques de blé dur élite. Pour cela, trois populations de cartographie, comprenant chacune environ 100 F7-RIL (lignées pures recombinantes ou « recombinant inbred lines »), ont été développées à partir de croisements entre la lignée expérimentale de blé dur DBC-480, portant une introgression de Fhb1, et les cultivars de blé dur Karur, Durobonus et SZD1029K. Les lignées ont été évaluées au champ, sur trois saisons, pour leur résistance globale à la fusariose après inoculation en spray de Fusarium culmorum. Des notations morphologiques (date de floraison, hauteur des plantes) ont également été réalisées afin d'évaluer leur influence sur l'infestation. Les lignées ont été génotypées à l’aide de marqueurs SSR et de marqueurs GBS (génotypage par séquençage ou « genotyping-by-sequencing ») développés par DArTseq. L’analyse de liaison a permis d’identifier des QTL de résistance sur les bras des chromosomes 2BL, 3BS, 4AL, 4BS, 5AL et 6AS. DBC-480 contribuait à l’allèle de résistance à tous ces loci. Le QTL sur 3BS a été détecté au sein des trois populations centré sur l’intervalle de Fhb1, confirmant, pour la première fois, son introgression dans le blé dur. L’évaluation de la résistance à la propagation après inoculation ponctuelle, réalisé au sein d’une des trois populations, a également permis de valider l’effet de Fhb1 sur la résistance de type 2 chez le blé dur. La hauteur des plantes influe fortement sur la résistance globale à la fusariose et, en particulier, l’allèle de nanisme Rht-B1b est associé à une plus grande sensibilité à la maladie dans les trois populations. Cependant, l’effet négatif de Rht-B1b sur la résistance est largement compensé dans les lignées possédant Fhb1. Des lignées semi-naines avec un meilleur niveau de résistance ont été sélectionnées et favoriseront le développement de cultivars de blé dur résistants à la fusariose. / Fusarium head blight (FHB) is a devastating disease affecting small-grain cereals worldwide causing yield and quality losses. FHB affects food safety due to the contamination of infected grains by mycotoxins. Host plant resistance is considered the most efficient and sustainable approach to contain FHB and mycotoxin contaminations. In durum wheat (Triticum durum Desf.) breeding for FHB resistance remains a challenge due to its extreme susceptibility and to lack of genetic variation available in the primary durum wheat gene pool. The primary goal of this thesis was to evaluate the effect of Fhb1, the major common wheat (Triticum aestivum L.) FHB resistance QTL, in elite durum wheat background. Three F7-RIL (recombinant inbred lines) mapping populations of about 100 lines were developed from crosses between the durum wheat experimental line DBC-480, harboring Fhb1, and the durum wheat cultivars Karur, Durobonus and SZD1029K. The RILs were tested under field conditions by artificial spray inoculation with Fusarium culmorum in three seasons. Morphological traits (flowering date, height) were also recorded to assess their influence on FHB infestation. Genotyping of the lines was performed with SSR and genotyping-by-sequencing (GBS) DArTseq markers. QTL analysis identified genomic regions associated with FHB resistance on chromosome arms 2BL, 3BS, 4AL, 4BS, 5AL and 6AS. DBC-480 contributed the resistant allele at all loci. Fhb1 was detected in all three populations, demonstrating for the first time its successful deployment in durum wheat. The effect of Fhb1 on FHB resistance in durum wheat was further verified by evaluating type 2 resistance in one of the three populations. Plant height had a strong influence in modulating FHB severity. Although the semi-dwarf allele Rht-B1b was associated with increased FHB susceptibility, its negative effect was efficiently counterbalanced in lines carrying Fhb1. Semi-dwarf lines with enhanced levels of resistance were selected and will assist the development of FHB resistant cultivars.

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