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1
Islam-Faridi, M. Nurul. "Genetical studies of grain protein and developmental charcters in wheat." Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235917.
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Malalgoda, Marie Maneka Rajini. "Pre-Harvest Glyphosate Use During Wheat Cultivation: Effects on Wheat Chemistry and Human Gut Microbiota." Diss., North Dakota State University, 2018. https://hdl.handle.net/10365/31707.
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Glyphosate is the most widely used herbicide in the world which is sometimes utilized as a pre-harvest desiccant during wheat cultivation. It inhibits the 5-enolpyruvylshikimate-3-phosphate synthase enzyme in the shikimic acid pathway in plants. Although this pathway is not found in humans, it is present in human gut microbiota. In this context, the goal of this study was to examine the effect of pre-harvest glyphosate application on wheat quality, biochemical characteristics and human gut microbiota. The results of this study indicated that the effects of glyphosate on wheat quality is more pronounced when applied at soft dough stage. Glyphosate lowered B-type starch granules and vice versa for A-type granules and it changed the proportions of rapidly digestible and slowly digestible starch. Starch amylopectin chain length distribution was also impacted although the effects were different when applied at the two stages. Glyphosate lowered the molecular weight of SDS extractable and unextractable proteins when applied as a desiccant. Additionally, shikimic acid accumulation was especially high in samples treated at soft dough stage. As for gut microbiota, the results indicated that glyphosate may not have a profound impact on metabolite production by gut microbiota, although there maybe effects on bacterial population dynamics. Overall, the current study indicates that glyphosate applied pre-harvest has some effects on wheat physicochemical properties and gut microbiota. In the context of wheat chemistry, the effects of glyphosate on the shikimic acid pathway, followed by subsequent accumulation of shikimic acid and effects on carbon flow may cause changes in the biosynthesis of starch and proteins. Glyphosate could impact enzyme activity, as it can interact with metals that are required as co-factors in enzyme catalyzed reactions. Glyphosate’s effect on intermolecular interactions between starch and protein, and other macromolecules such as dietary fiber, may also influence the overall chemistry of plant components. Although the effects of glyphosate on gut microbiota are not clear-cut, this exploratory study is a stepping stone in this area of research. In conclusion, the observations made in this study should be investigated further to determine causal links and relationships.
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Sharma, Sapna. "Genetics of Wheat Domestication and Septoria Nodorum Blotch Susceptibility in Wheat." Thesis, North Dakota State University, 2019. https://hdl.handle.net/10365/29767.
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T. aestivum ssp. spelta Iranian type has long been thought to potentially be the direct non-free threshing hexaploid progenitor. I evaluated a RIL population derived from a cross between CS and Iranian spelta accession P503 to identify loci suppressing free-threshabilty in P503. Identification of QTL associated with threshability in region known to harbor the Tg2A gene, and an inactive tg2D allele supported the hypothesis of Iranian spelta being derived from a more recent hybridization between free-threshing hexaploid and emmer wheat. Parastagonospora nodorum is an important fungal pathogen and secretes necrotrophic effectors that evoke cell death. In this research, a DH population segregating for Snn5 was used to saturate Snn5 region of chromosome 4B with molecular markers. The physical distance between Snn5 flanking markers was narrowed to 1.38 Mb with genetic distance of 2.8 cM. The markers developed in this study will provide a strong foundation for map-based cloning of Snn5.
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Hassan, Khalida Abdul-Karim. "The effect of soil conditions on nutrient availability, nutrient uptake and productivity of spring wheat." Thesis, University of Manchester, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329590.
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Rial, Lovera K. E. "Evaluation of cultivation, legume undersowing and nitrogen interventions on wheat development." Thesis, Coventry University, 2015. http://curve.coventry.ac.uk/open/items/164277f7-8c38-47e4-aaf8-9959494dc390/1.
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Agriculture is facing increasing pressures to produce food that meets specific market and/or nutrition requirements, while using inputs in such a way that can ensure economic and environmental goals more efficiently. Two field experiments were conducted in 2013 and 2014 at the Royal Agricultural University’s Harnhill’ Manor Farm, Cirencester, UK to evaluate the influence of selected cultivation techniques, N fertilisation and undersowing legumes on spring wheat growth and development. To explore, in particular, the yield components contributing to grain yield and quality, as well as weed pressure influences together with changes in soil mineral N (SMN) content. Cultivation techniques included conventional tillage (CT), high intensity non-inversion tillage (HINiT) and low intensity non-inversion tillage (LINiT); mineral N fertilisation rates of 0, 70, 140 and 210 kg N ha-1 and two undersown legume species, black medic and white clover, plus no undersowing treatment. The performance of the management practices was strongly influenced by the weather. In 2013, under dry weather conditions, LINiT seems to be a suitable alternative to CT, while N fertilisation did not encourage greater grain yield. In 2014, CT appears to be a more reliable practice, while the application of up to 140 kg N ha-1 seemed to be enough to increase grain yield. Dry weather conditions at the time of broadcasting did not allow the undersowing species to be fully established, resulting in no effects on weed control and crop growth. In 2013, the initial poor plant establishment and slow crop growth under LINiT was compensated for by the soils ability to retain moisture, and thereby reducing crop water stress during the dry periods. This finally resulted in statistically similar grain yield to CT. In 2014 when water was not a limiting factor, poor plant establishment and crop growth, low SMN content and high weed pressure under LINiT resulted in lower grain yield than CT. In both years, HINiT resulted in low SMN content and high weed pressure resulting in poor grain yield. Across experiments, HINiT and LINiT saved energy-use and production costs, but CT could be more energy-use efficient and have high economic return if higher grain yield is assured. N fertilisation significantly promoted wheat growth, although under dry conditions with higher residual soil N, the N fertilisation did not increase yield. Under low SMN level applying up to 140 kg N ha-1 increased grain yield produced, but N fertilisation is energy consuming and its use does not always ensure a higher economic return.
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Harris, Nigel. "A transposable element of wheat." Thesis, University of Cambridge, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.330215.
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Jamjod, Sansanee. "Genetics of boron tolerance in durum wheat." Title page, contents and abstract only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phj324.pdf.
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Bibliography: leaves 234-256. Genetic studies of tolerance of durum wheat (Triticum turgidum L. var durum) to high concentrations of boron (B) were undertaken to identify genetic variation in response to B, the mode of gene action, number of genes and chromosomal locations of genes controlling tolerance. Results demonstrated that tolerance to B is under simple genetic control as observed in bread wheat. High levels of tolerance can be transferred into sensitive commercial varieties via backcrossing and selection can be performed during seedling growth at early generations.
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Zwart, Rebecca Susan. "Genetics of disease resistance in synthetic hexaploid wheat /." St. Lucia, Qld, 2003. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17369.pdf.
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Vijaya, Bhaskar A. V. "Cultivation regimes and legume cover crops for organic wheat (Triticum aestivum) production." Thesis, Coventry University, 2014. http://curve.coventry.ac.uk/open/items/0eee127c-9732-4d39-bb0b-74535212c726/1.
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Field trials were conducted in 2010/11, 2012 and 2013 at the Royal Agricultural University’s Soil Association certified organic Harnhill Manor Farm, Gloucestershire, UK (NGR SP 075 006), to investigate suitable cultivation techniques and legume cover crops for winter and spring wheat production. Cultivation treatments included conventional tillage (CT), low residue non-inversion tillage (LRNiT) and high residue non-inversion tillage (HRNiT) as main plots while undersowing white clover (WC), black medic (BM) or no undersowing (Nus) as subplots. Wheat establishment, growth, grain yield and weeds infestation were assessed to determine the feasibility of these husbandry techniques. For winter wheat in 2010/11, LRNiT seems to be an acceptable alternative for CT. However, for spring wheat in 2012 and 2013, CT seems to be more reliable management option. The performance of undersown legumes was highly weather reliant and inconsistent in the seasons studied. Plant establishment and the succeeding yield parameters were positively related to grain yield. CT had significantly higher plant establishment than LRNiT or HRNiT in each season. For winter wheat, the competition and compensation on shoot density among CT and LRNiT did potentially outweighed cultivation-induced effects on plant establishment. This condition resulted in statistically equivalent crop growth and yields with LRNiT to that of CT. In contrast, for spring wheat in 2012 and 2013, CT that had significantly higher plant establishment also resulted in better crop growth and greater grain yields than other cultivation treatments. In all seasons, HRNiT had significantly lower plant establishment and also reduced grain yields, compared with LRNiT or CT. More soil cultivation also significantly reduced total weeds than less tilled soil such as HRNiT. On the basis of weed species, significantly higher broadleaf weeds were present under CT and significantly higher grass weeds were present under HRNiT. Out of three investigated years, legume cover crops effects were clearly observed only in 2012 with spring wheat. More vigorous growth of WC showed a significantly inverse relationship with broadleaf weeds and total weeds, compared with slow growing BM. This situation, resulted in non-significant yield components or grain yield reduction, compared with non-undersown spring wheat. In this context, white clover seems to be more suitable legume cover crop than black medic.
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Riches, Eleanor Ruth. "The genetics and function of alkylresorcinols in wheat." Thesis, University of East Anglia, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251391.
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Jones, M. C. "Replication of DNA by isolated wheat chloroplasts." Thesis, University of Hertfordshire, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356358.
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Schultz, Thia. "Elucidating functional interactions between the Russian wheat aphid (D. noxia Kurjumov) and bread wheat (Triticum aestivum L.)." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95802.
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Thesis (PhD)--Stellenbosch University, 2014.ENGLISH ABSTRACT: The Russian wheat aphid (Diuraphis noxia, Kurdj., Hemipetra, Aphididae, RWA) is an important pest of wheat, causing large-scale damage and yield losses. Various studies have been done at a transcriptomics level, including complementary DNA-amplified fragment length polymorphisms (cDNA-AFLPs), suppressive subtractive hybridization (SSH) and micro-array, which have identified genes putatively involved in RWA resistance. Even though these candidate genes have been identified, their role in host defence still needs to be verified using a functional genetics approach. In this study virus induced gene silencing (VIGS) using a barley stripe mosaic virus (BSMV) vector, has been utilized to knock-down candidate genes of interest in a wheat cultivar with the Dn1-resistance gene (TugelaDN). In this study it was hypothesized that genes involved in the hypersensitive response (HR) may contribute towards resistance and were thus targeted for silencing. These include glutathione-S-transferase (GST), superoxide dismutase Cu/Zn (SOD) and thylakoid-associated ascorbate peroxidase (tAPX). However, since aphid feeding also results in wounding, the genes were also analyzed under wounding only. Aphid fecundity is considered an indicator of involvement in RWA resistance, as susceptible plants result in higher aphid fertility. Findings in the study suggest that with wounding only, that Dn1 containing plants produce a greater hypersensitive response than susceptible controls. Ascorbate peroxidase was found to be important for wounding-induced resistance in Dn1 wheat plants. Under infestation conditions, silencing of superoxide dismutase Cu/Zn (SOD) and thylakoid-associated ascorbate peroxidase (tAPX) was found not to have an effect on aphid fertility and thus are not directly involved in resistance signaling. Knock-down of a phi-class glutathione-S-transferase F6 (TaGSTF6) transcripts however, had a large effect on aphid nymph numbers and thus may contribute to Dn1-resistance. Putative resistance genes silenced under aphid infestation conditions were a nucleotide binding protein (NBP) and resistance gene analogue 2 (RGA2). Analysis of NBP revealed its identity as a part of the iron homeostasis machinery in the cytosol, responsible for Fe-cluster assembly. Silencing of both NBP and RGA2 resulted in the expression of a susceptible phenotype. T10rga2-1A is an NBS-LRR protein known to be required for rust resistance in concert with resistance gene Lr10. T10rga2-1D silenced treatments resulted in susceptibility and plant death after aphid infestation, suggesting that T10rga2-1D may be a good up-stream candidate in Dn1-resistance.
AFRIKAANSE OPSOMMING: Die Russiese-koringluis (RWA) is ‘n pes wat ‘n belangrike ekonomiese invloed op koring opbrengste het en infestasie kan tot grootskaalse skade en oes verlies lei. Verskeie studies, onder andere komplimentêre DNA amplifiseerde fragment polimorfismes (cDNA-AFLPs), onderdrukkende onderskeidende hibridisaie (SSH) en mikro-reekse wat voorheen op transkriptomiese vlak gedoen is, het moontlike gene wat by RWA weerstand betrokke is, geïdentifiseer. Alhoewel hierdie gene reeds geidentifiseer was, hulle rol is nogtans onbekend. Dié gene moet nog getoets word, duur funksionele genetiese benaderingste maak. In hierdie studie is ‘n gars streep mosaïek virus vektor (BSMV) gebruik om kandidaat-gene van belang in ‘n Dn1-weerstandige geen-bevattende kultivar (TugelaDN) te onderdruk. Ondrukking van gene het deur middel van virus geïnduseerde geen onderdrukking (VIGS) plaasgevind. In hierdie studie is die hipotese gestel dat die gene betrokke by die hipersensitiewe reaksie (HR) ‘n invloed op plantweerstand kan hê en is dus geteiken vir geen-onderdrukking-studies. Hierdie gene het die volgende ingesluit: glutatioon-S-transferase (GST), superoksied dismutase Cu/Zn (SOD) en askorbien peroksidase (APX). Egter, omdat luisinfestasie ook tot verwonding aanleiding gee, is die onderdrukte gene ook onder alleenlik verwondingstoestande getoets. Luis vrugbaarheid is gebruik as indikator van betrokkenheid omdat meer vatbare plante ‘n hoër luis vrugbaarheid tot gevolg het. In die studie is gevind dat onder alleenlik verwondingkondisies, plante wat Dn1 bevat, ‘n groter hipersensitiewe respons vertoon, as vatbare kontroles. Daar is verder gevind dat askorbien peroksidase ‘n belangrike rol tydens verwondings-geïnduseerde weerstand in Dn1-plante speel. Daar is verder bevind dat die onderdrukking van superoksied dismutase Cu/Zn (SOD) en ‘n tilakoïed-geassosïeerde askorbien peroksidase (tAPX). Onder luis-infestasie kondisies, geen effek op luisvrugbaarheid gehad het nie en dus nie direk by die weerstandsrespons betrokke is nie. Die onderdrukking van ‘n phi-klas glutatioon-S-transferase F6 (TaGSTF6) het egter ‘n groot invloed op luis-vrugbaarheid gehad en kan dus ‘n rol in Dn1-weerstand speel. Die moontlike weerstands gene, geïdentifiseer as nukleotied bindings proteïen (NBP) en weestandsgeen anoloog 2 (T10rga2-1D), is getoets onder luis-infestasie kondisies. Die analise van NBP het getoon dat dit ‘n integrale deel van die yster homeostase meganisme in die sitosol, wat vir Fe-kluster samestelling verantwoordelik is, vorm. Onderdrukking van beide die NBP en T10rga2-1D het tot die uitdrukking van ‘n vatbare fenotipe aanleiding gegee. T10rga2-1A is ‘n NBS-LRR proteïen wat bekend is om noodsaaklik te wees tydens roes weerstandigheid in teenwoordigheid van die weerstandsgeen Lr10. T10rga2-1D-onderdrukte behandelings het tot vatbaarheid aangeiding gegee en daartoe gelei dat plante na luis-infestasies doodgaan. Hierdie resultate dui dus ‘n rol vir T10rga2-1D in Dn1-weerstandigheid aan, en suggereer verder dat hierdie geen ‘n goeie stroom-op kandidaat in Dn1-weerstandigheid is.
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Kaehne, Ian D. "Improving wheat by composite crosses based on `cornerstone' nuclear male sterility / Ian D. Kaehne." Adelaide, 1986. http://hdl.handle.net/2440/18530.
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1 v.Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
Thesis (Ph.D.)--University of Adelaide, Dept. of Agronomy, Waite Agricultural Institute, 1986
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Campbell, Jackie Bridget. "Increasing wheat hardness locus functionality by increasing puroindoline copy number and introduction of novel alleles." Thesis, Montana State University, 2007. http://etd.lib.montana.edu/etd/2007/campbell/CampbellJ0507.pdf.
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Mantovani, Eder Eduardo. "Wheat Traits Variations, Associations, and Potential Improvement from Crosses of Elite X Non-Adapted Germplasm." Thesis, North Dakota State University, 2011. https://hdl.handle.net/10365/29911.
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Wheat improvement most often has been accompanied by a narrowing germplasm base, as newer cultivars have been derived from intercrosses between elite germplasm. However, there is a concern that narrow germplasm may restrict breeding improvement for important traits such as resistances to new biotic and abiotic stresses. In addition to germplasm base, the wheat kernel is a major component of wheat grain yield and an important factor for milling characteristics. Focusing on wheat kernel characteristics might be a key element to improve wheat genotypes for agronomic and quality traits. With the intention to broaden the wheat germplasm, and to explore the associations between kernel traits and agronomic as well as quality traits, a two-year study was initiated in 2009 to examine the influence of the kernel traits on the agronomic and quality attributes of a 160 Recombinant Inbred Lines (RIL) population developed from an adapted (ND 705) and a non-adapted genotype (PI 414566). The experiment was conducted at Prosper and Carrington, North Dakota, during 2009 and 2010. The RIL population had a better performance at Carrington than Prosper due to favorable climatic conditions at this location, in 2009 and 2010. The results in this study showed that kernel traits had a high correlation among them and they exhibited continuous variations suggesting a polygenic inheritance. Grain yield, kernel volume weight (KVW), and flour extraction were highly correlated with kernel width, length/width ratio, weight, and area. Eight RIL yielded better than the adapted parent ND 705 and two of the RIL along with three checks were significantly superior for gram yield compared with the other genotypes across all environments. Although the non-adapted parent has a facultative grown habit, several RIL required fewer days to flower compared to the adapted parent. Two RIL had better flour extraction compared to the other genotypes included in this study. These results indicated that kernel traits can play a significant role in improving agronomic and quality traits. Higher values for grain yield, KVW, and flour extraction were significantly associated with
spheroid or round shape (short and plump), large, and heavy kernels. The high agronomic and quality attributes showed by some RIL demonstrated that the use of a non-adapted parent can broaden the genetic variability while increasing the genetic gain for certain traits. Also, breeders should pay attention to kernel size and shape during the parental selection for the development of populations with improved agronomic and quality traits.
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Arraiano, Lia Susana. "Genetics of resistance of wheat to septoria tritici blotch." Thesis, University of East Anglia, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390648.
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The research described in this týesis was focused on achieving a better understanding of the genetics of resistance of wheat to septoria tritici blotch (Mycosphaerella graminicola). Firstly, a detached leaf technique that could be a useful complement to field trials and an alternative to whole seedling assays in assessing cultivar resistance and investigating the genetics of the host-pathogen interaction was developed. Sets of inter-varietal substitution lines, developed at the John Innes Centre, involving known and possible sources of resistance to septoria tritici blotch, were tested with several single-pycnidium isolates in both the seedling and the adult plant stage. Two specific resistance genes were identified on chromosomes of `Synthetic 6x' and `Bezostaya 1'. A resistance gene, named Stb5, was identified using the M. graminicola isolate IP094269 and mapped on the short arm of chromosome 7D of `Synthetic 6x'. `Bezostaya I's specific resistance gene to IP0323 seems to be located in the same region as Stb6, and is indeed likely to be the same gene. `Bezostaya 1' and `Cappelle Desprez' also seemed to carry components for partial resistance. Triticum macha resistance to septoria tritici blotch on the other hand was both of a specific and isolatenon- specific nature. The specific components carried by T. macha seemed to be the Stb6 gene and an additional resistance gene, but it was not possible to identify their chromosomal location. To evaluate the relationship of heading date and plant height components to severity of septoria tritici blotch, an F6 single seed population of `Apollo' x `Thesee' was studied in natural conditions. Septoria tritici blotch levels were substantially lower in later-heading than in earlier-heading lines. Total plant height had comparatively little effect on disease severity, but increased distance between the two upper leaves increased disease levels. `Apollo' seems to carry partial resistance involving more than one QTL.
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Miller, T. E. "A study of chromosome pairing in wheat." Thesis, University of East Anglia, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267558.
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Vaughan, Tristan John. "Isolation and analysis of genes encoding wheat ribosomal proteins." Thesis, University of Leeds, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328181.
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Zhang, Hui. "Triticeae genome relationships and wheat flowering time genes." Thesis, Open University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390896.
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Wessels, Willem Gerhardus. "Mapping genes for stem rust and Russian wheat aphid resistance in bread wheat (Triticum aestivum)." Thesis, Stellenbosch : Stellenbosch University, 1997. http://hdl.handle.net/10019.1/55580.
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Thesis ( MScAgric) -- Stellenbosch University, 1997.ENGLISH ABSTRACT: Stem rust is considered the most damaging of the wheat rusts causing yield losses of more than 50% in epidemic years. Similarly, Russian wheat aphids (RWA) can be regarded as one ofthe most devastating insect pests of wheat. Yield losses due to R W A primarily result from a reduction in plant resources (sucking plant sap). Secondary losses are incurred by viruses transmitted during feeding. Mapping disease and insect resistance genes that are effective against prevailing pathotypes and biotypes of South Africa will optimize their utilization in breeding programmes. The wheat line, 87M66-2-l, is homozygous for a single dominant stem rust resistance gene located on chromosome lD. This stem rust resistance gene has been derived from Triticum tauschii accession RL5289 and is here referred to as Srtau. The aim of this study was to determine the chromosome arm involved. Following the chromosome arm allocation of Srtau, its possible linkage with the genes Rg2, Lr 21 , Sr X and Sr 33 was studied. A telosomic analysis has shown that Srtau is located on chromosome arm 1 DS and is linked to the centromere with a recombination frequency of 21 ± 3 .40%. Glume blotch and a heavy mildew infection of segregating families planted in the field in 1996 made the linkage study between Lr 21 (leaf rust resistance) and Rg2 (glume colour) impossible. However, estimated linkages of 9 ± 1.9 map units between Sr33 (stem rust resistance) and Srtau, ± 6 map units between Sr X (stem rust resistance) and Sr 3 3 and ± 1 0 map units between Sr X and Srtau suggested that SrX, Sr33 and Srtau are closely linked on I DS. Taking existing map data into consideration, it seems that the most likely order of the genes is: centromere - Srtau - Sr 3 3 - Sr X. A single dominant R W A resistance gene, Dn5, was identified in the T aestivum accession 'SA 463' and is located on chromosome 7D. The aim ofthis study was to determine the chromosome arm involved. The possible linkage of Dn5 with the endopeptidase locus, Ep-D1 b. and chlorina mutant gene, cn-D1, was then studied. Endopeptidase zymograms of 'SA 463' revealed two unknown polymorphisms. F 2 monosomic analyses involving the chromosomes 7 A, 7B and 7D were performed in an attempt to identify the loci associated with these polymorphisms. Dn5 was mapped on chromosome arm 7DL. A recombination frequency of60 ± 4.53% between Dn5 and the centromere suggested the absence of linkage. Linkage between Ep-Dl and cn-Dl could not be calculated as a result of similar isoelectric points of the 7DL encoded endopeptidases of the parental material studied. Recombination frequencies of32 ± 4.97% between Dn5 and EpDl and 37 ± 6.30% between Dn5 and cn-Dl were, however, encountered. The two novel endopeptidase alleles encountered in 'SA 463' were designated as Ep-Dle and Ep-Ald. A RWA resistance gene was transferred from the rye accession ' Turkey 77' to wheat and in the process the RWA resistant wheat lines 91M37-7 and 91M37-51 were derived. No rye chromatin could be detected in these plants following C-banding. The aim of this study was to determine (i) on which chromosome the gene(s) is located, and (ii) whether the resistance can be the result of a small intercalary translocation of rye chromatin. A monosomic analysis of the RWA resistance gene in 91M37-51 has shown that a single dominant resistance gene occurs on chromosome 7D. The use of rye-specific dispersed probes did not reveal any polymorphisms between the negative controls and RW A resistant lines 91M3 7- 7 and 91M37-51 which would suggest that it is unlikely that the resistance was derived from rye.
AFRIKAANSE OPSOMMING: Stamroes word as die mees vemietigende graanroessiekte beskou en het in epidemiese jare oesverliese van meer as 50% tot gevolg. Russiese koringluise is eweneens een van die emstigste insekplae van koring. Russiese koringluise veroorsaak oesverliese deurdat dit plantsap uitsuig en die plant van voedingstowwe beroof. Dit tree egter ook as 'n virusvektor op en kan so indirekte oesverliese veroorsaak. Kartering van siekte- en insekweerstandsgene wat effektief is teen die Suid-Afrikaanse patotipes en biotipes, sal hulle gebruik in teelprogramme optimiseer. Die koringlyn, 87M66-2-l , is homosigoties vir 'n dominante stamroes-weerstandsgeen wat op chromosoom ID voorkom. Hierdie weerstandsgeen is uit die Triticum tauschii aanwins, RL5289, afkomstig en word hiema verwys as Srtau. Daar is gepoog om te bepaal op watter chromosoomarm Srtau voorkom, waama sy koppeling met betrekking tot die gene Rg2, Lr21 , SrX en Sr33 bepaal is. 'n Telosoomanalise het getoon dat Srtau op chromosoom-arm 1 DS voorkom en gekoppel is aan die sentromeer met 'n rekombinasie-frekwensie van 21 ± 3.40%. Segregerende populasies wat in 1996 in die land geplant is, is hewig deur aarvlek en poeieragtige meeldou besmet en dit het die moontlike bepaling van koppeling tussen Lr21 (blaarroesweerstand) en Rg2 (aarkaffie kleur) belemmer. Koppelingsafstande van 9 ± 1. 9 kaart-eenhede tussen Sr 33 (stamroesweerstand) en Srt au, ± 6 kaart -eenhede tussen Sr X ( stamroesweerstand) en Sr 3 3 en ± 1 0 kaart -eenhede tussen SrX en Srtau is geraam en toon dat SrX, Sr33 en Srtau nou gekoppel is. Die waarskynlikste volgorde van die gene op lDS is: sentromeer- Srtau- Sr33- SrX. 'n Enkele dominante Russiese koringluis-weerstandsgeen, Dn5, is in dieT aestivum aanwins 'SA 463 ' ge"identifiseer en kom op chromosoom 7D voor. Die studie het ten doel gehad om te bepaal op watter chromosoom-arm Dn5 voorkom, asook wat die koppeling van Dn5 met die endopeptidase lokus, Ep-Dl, en die chlorina mutante geen, cn-Dl , is. Endopeptidase simograrnme van 'SA 463' het twee onbekende polimorfismes getoon. Die gene wat kodeer vir hierdie twee polimorfismes is met behulp van F2 monosoom-analises wat die chromosome 7 A, 7B en 7D betrek, gei:dentifiseer. Dn5 is op chromosoom 7DL gekarteer. 'n Rekombinasie-frekwensie van 60 ± 4.53% is gevind vir die sentromeer en Dn5 en dui op die afwesigheid van koppeling. Koppeling tussen Ep-Dl en cn-Dl kon nie bepaal word nie omdat die endopeptidase bande geproduseer deur die ouerlike materiaal wat in die studie gebruik is, nie met sekerheid in die nageslag onderskei kon word nie. Rekombinasie-frekwensies van 32 ± 4.97% tussen Dn5 en Ep-Dl en 37 ± 6.30% tussen Dn5 en cn-Dl is egter bereken. Dit word voorgestel dat daar na die twee onbekende endopeptidase-allele wat in 'SA 463 ' voorkom, verwys word as Ep-Dle en Ep-Ald. 'n Russiese koringluis-weerstandsgeen is uit die rog-aanwins, 'Turkey 77', oorgedra na koring en in die proses is die Russies koringluis weerstandbiedende lyne, 91M37-7 en 91M37-51 , geproduseer. Geen rog-chromatien kon egter met behulp van C-bande in hierdie lyne waargeneem word nie. Die doel van die studie was om te bepaal (i) op watter chromosoom die geen(e) voorkom, en (ii), of die Russiese koringluis weerstandsgeen die gevolg kan wees van 'n klein interkalere translokasie van rog- chromatien. 'n Monosoom-analise van die Russiese koringluis-weerstandsgeen in 91M37-51 het getoon dat 'n enkele dominante weerstandsgeen op chromosoom 7D voorkom. Rog-spesifieke herhalende peilers het geen polimorfismes tussen negatiewe kontroles en die Russiese koringluis weerstandbiedende lyne 91M37-7 en 91M37-51 getoon nie. Dit is dus onwaarskynlik dat die weerstand in die lyne uit rog verhaal is.
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Ahmed, Sanussi Yonees. "Novel sources of phosphours [i.e. phosphorous] for wheat cultivation in the South of Libya." Thesis, University of Newcastle Upon Tyne, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.427285.
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Badenhorst, Pieter Engelbertus. "Poging om die Aegilops sharonensis-verhaalde Lr56/Yr38 koringtranslokasie te verkort." Thesis, Stellenbosch : Stellenbosch University, 2008. http://hdl.handle.net/10019.1/3083.
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Bradley, Bernadette. "The granule-bound starch synthase genes of wheat." Murdoch University, 2003. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20040706.142601.
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Wheat (Triticum aestivum) is the worlds most widely grown and economically important crop. It is both a staple food for humans and a raw material for many industrial processes. World trade in wheat is important for economic stability and an ability to grow wheat is a valuable national resource. Wheat is Australias major crop with an annual production of about 23 million tonnes.
One-quarter of this is used domestically and meets all of Australias requirements; the remaining three-quarters is exported. Therefore, Australias wheat industry provides both the national staple food source and the basis of an export industry worth almost 2 billion dollars.
There is great potential for further genetic improvement of wheat, not only by increasing grain yields by improved resistance to pathogens and tolerance to adverse environmental conditions, but also by improving functional quality. For example, one can change the physical properties of the storage components, starch and protein, to increase their usefulness in conventional applications and for novel uses. Some examples of the physical properties of starch affecting its uses are, the large starch granules from wheat that are suitable to make carbonless copy paper (Bligh, 1999), the small starch granules from rice that are used as a fat substitute because the a comparable mouthfeel, the high-amylose starches that have film-forming properties desirable for fried food coating batters and some forms of plastics, and the low-amylose starch that swells more in water and can be used for soft foods such as Asian noodles. Continued improvement of wheat is vital to meet the quantity and quality demands of the local and international wheat markets.
One specialty market for Western Australian wheat, is export to Japan and South Korea for the production of Japanese white salted Udon noodles, an export market worth more than $200M pa (Garlinge, 1996). Udon noodles have specific eating qualities including a light, creamy, uniform colour, a bright appearance to the noodle, a soft but elastic texture to the noodle, and a smooth mouthfeel, all of which result from the quality of the wheat flour starch they are made from(Crosbie, 1991; Batey et al., 1997; Zeng et al., 1997). The Australian Standard White Noodle (ASWN) wheat that Australia exports to produce Udon noodles is soft-grained, white coloured, contains between 9.5% and 11.5% protein, and produces flour of fine particle size with little starch damage (V. Reck, DAWA, pers. comm.). The flour also has good starch-swelling characteristics, moderate dough strength and good dough extensibility.
The good starch-swelling characteristics of the flour result, for the most-part, from containing relatively less of the starch amylose than other varieties (22-23% compared to 25%), a property controlled by the GBSS genes (Nelson and Rines, 1962; Garlinge, 1996). When less amylose is present in the starch granule as it is heated in water, the amylopectin matrix inside the granule can swell, causing the finished Udon noodle to be soft. When more amylose is present in the starch granule, the amylopectin matrix cannot swell as much, and the finished noodle is too hard to have the desired mouthfeel of an Udon noodle. The amylose fraction of starch is produced by the granule-bound starch synthase (GBSS) enzymes, encoded by the GBSS genes. The overall aim of the research described in this thesis was to investigate the genomic organization of the GBSS genes of wheat. Since the GBSS genes influence wheat starch quality, an understanding of the action of these genes is needed for future improvement of starch quality in noodle-wheats.
There are three loci for GBSS genes in wheat, and these are located on chromosomes 4A, 7A and 7D. Both wild-type alleles and non-functional null alleles exist at each locus. At the start of the project, these alleles had not been sequenced and the molecular differences between the alleles were not known. Other GBSS alleles were also thought to exist in Australian varieties that had yet to be identified and characterised. GBSS genes from a selection of wheat varieties, and from all three GBSS loci, were sequenced searching for DNA polymorphisms that were different between the different alleles. If any DNA polymorphisms were found to result in GBSS protein sequence differences, or differences in GBSS enzyme expression, they could influence the functional characteristics of the starch. Identifying GBSS allelic variants would enable molecular markers to be developed to detect the alleles and investigate their potential effects upon starch quality.
Different PCR-based methods and one non-PCR-based method were used to investigate the genomic organization of the GBSS genes in a selection of genetically diverse wheat varieties. The 31 wheat varieties studied included noodle-wheat varieties from the ASWN classification, varieties with similar genetic background to ASWN wheat varieties but of unsuitable quality for noodle production, unrelated varieties of Australian Standard White wheat, and were compared with those Chinese Spring varieties described in the literature. Most of the varieties are grown in the Western Australian wheatbelt and southern regions, either for export and the production of Asian noodles, or for the production of domestic baked-goods.
A 500bp section from the middle of the GBSS genes was amplified, from a selection of wheat varieties, and sequenced to search for polymorphisms. Twenty-one single nucleotide differences were found between genes at the three loci and two PCR-based tests were designed to validate these differences as Single Nucleotide Polymorphisms (SNPs). A novel microsatellite was also discovered in intron 4 of the GBSS 7A genes. This (TGCCG)n microsatellite was variable between wheat varieties and so defines a novel allele in the Australian germplasm present at a frequency of 40%. A PCR-based test was developed to identify this variable locus. However, the new GBSS allele was not linked to Flour Swelling Volume (FSV) quality properties.
The variable microsatellite locus Xsun1 (Shariflou and Sharp, 1999) in the 3 untranslated region of the GBSS genes and linked to GBSS allelic variation was used to genotype a wheat breeding population for its GBSS status. The population (n=69) contained combinations of wild-type and null alleles at the 7A and 7D loci. Once genotyped using this marker, the GBSS alleles were assessed for possible likage to starch variation. Although the trend suggested that the presence ofnull alleles increased the FSV, the size of the population tested was too small for the differences in FSV between wild-type and partially-waxy wheats to be statistically significant.
The linkage between the Xsun1 microsatellite variation and the (TGCCG)n microsatellite variation from intron 4 of the GBSS 7A genes was studied. By combining these two microsatellite loci, which are closely linked to the GBSS coding regions, GBSS genes at the 7A locus could be separated into 12 allelic groups. Although none of these groups could be linked to specific changes in starch qualities, they can be analysed further for functional differences.
In order to access a larger section of the GBSS genes using PCR, new PCR primers were designed and optimized to amplify segments of the GBSS genes. Primers for GBSS genes tend to generate many PCR products, but many of these were shown to be non-specific. These artifacts could be reduced by increasing the annealing temperatures, and non-specific priming was repressed by the presence of the second primer in the PCR reaction. Using one primer set, a nearly 2000bp segment of the GBSS 7A genes from wheat varieties Kulin and Eradu was amplified and sequenced.
These sequences indicated the presence of single nucleotide differences that resulted in changed amino acids in the protein when compared to published GBSS sequences. The sequencing should be repeated to validate this result, which indicates that these are novel alleles, but it does suggest that allelic variation for GBSS exists in Australian wheat varieties and that these alleles are different from those described internationally.
The EcoR1, HindIII and BamH1 restriction enzyme sites surrounding the GBSS genes were identified using Southern hybridisation. This provided the potential to access the entire GBSS gene, including the promoter and untranscribed regions, by restriction enzyme mediated cloning of genomic DNA. However, attempts to clone the genomic GBSS genes into both plasmid and viral vectors were not successful.The potential existence of pseudogene copies of the GBSS genes in the wheat genome was investigated using both PCR and Southern hybridisation techniques. No evidence of GBSS pseudogenes was found, and this suggests that the wheat genome does not contain them. This result was unexpected since organisms with large genomes, such as wheat, normally contain repeated sequences and pseudogenes. However, the absence of repeated sequences and pseudogenes should be beneficial in molecular wheat breeding because it suggests that there will not be interference from non-coding GBSS sequences in identifying molecular markers to GBSS genes.
The GBSS genes present in Australian wheat varieties were similar enough to those described internationally that Australian breeders can make full use of research and molecular tests for GBSS genes developed elsewhere. However, enough variation exists between overseas and domestic varieties to warrant further investigation of novel GBSS alleles in domestic wheat, which may relate to differences in functionality.
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Liu, Chao-yin. "Variation and genetic control of prolamins in tetraploid wheats and their association with quality in durum wheat." Title page, contents and summary only, 1994. http://web4.library.adelaide.edu.au/theses/09PH/09phl783.pdf.
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Koebner, Robert Max David. "Controlled introgression of alien chromatin into wheat /." Title page, table of contents and abstract only, 1985. http://web4.library.adelaide.edu.au/theses/09PH/09phk77.pdf.
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Hofer, Julie M. I. "Regulation of gene expression and replication in wheat dwarf virus." Thesis, University of East Anglia, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334331.
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Horn, Marizanne. "Transfer of genetic resistance to the Russian wheat aphid from rye to wheat." Thesis, Stellenbosch : Stellenbosch University, 1997. http://hdl.handle.net/10019.1/55770.
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Thesis (MSc.) -- Stellenbosch University, 1997.ENGLISH ABSTRACT: An octoploid triticale was derived from the F1 of a Russian wheat aphid resistant rye, 'Turkey 77', and 'Chinese Spring' wheat. The alloploid was crossed (a) to common wheat, and (b) to the 'Imperial' rye to 'Chinese Spring' disomic addition lines. F2 progeny from these crosses were tested for Russian wheat aphid resistance and C-banded. Resistance was found to be associated with chromosome arm 1RS of the 'Turkey 77' rye genome. This initial work was done by MARAIS (1991) who made a RWA resistant, monotelosomic 1RS ('Turkey 77') addition plant available for the study. The F3 progeny of this monotelosomic addition plant was used to confirm the RWA resistance on chromosome 1RS. The monotelosomic addition plant was then crossed with the wheat cultivar 'Gamtoos', which has the 1BL.1 RS 'Veery' translocation. Unlike the 1RS segment in 'Gamtoos', the 'Turkey 77'- derived 1RS telosome did not express the rust resistance genes 5r31 and Lr26 which could then be used as markers. From the F1 a monotelosomic 1RS addition plant that was also heterozygous for the 1BL.1 RS translocation, was selected and testcrossed with an aphid susceptible common wheat, 'Inia 66'. Meiotic pairing between the .rye arms resulted in the recovery of five euploid, Russian wheat aphid resistant plants out of a progeny of 99 euploids. One recombinant also retained 5r31 and Lr26 and was allowed to self pollinate. With the aid of SOS-PAGE profiles, Russian wheat aphid resistant 1BL.1 RS translocation homozygotes were identified and it was possible to confirm that the Russian wheat aphid resistance gene was in fact transferred to the 1BL.1RS ('Veery') translocation. Two attempts were made to map the Russiar, wheat aphid locus or loci. (1) Telosomic mapping was attempted. For this purpose a plant with 2n = 40 + 1BL.1 RS + 1RS was obtained, and testcrossed with a Russian wheat aphid susceptible wheat. (2) A disomic, recombined 1BL.1 RS translocation line with Russian wheat aphid resistance but lacking the Lr26 and Sr31 alleles was crossed with 'Gamtoos' and the F1 testcrossed. The testcross in both strategies were done with 'Chinese Spring'. In the first experiment the Sr31 locus was located 10.42 map units from the Lr26 locus. The rust resistance data implied that the genetic distance estimates may be unreliable and therefore the laborious Russian wheat aphid resistance tests were not done. In the second experiment a Russian wheat aphid resistance gene was located 14.5 map units from the Lr26 locus. In the latter cross nonmendel ian segregation of the Russian wheat aphid resistance evidently occurred which implied that the estimated map distance may be inaccurate. It was also not possible to determine the number of genes involved from the data.
Digitized at 300 dpi Colour & b/W PDF format (OCR), using ,KODAK i 1220 PLUS scanner. Digitised, Ricardo Davids on request from ILL 25 April 2013
AFRIKAANSE OPSOMMING: 'n Oktaplo"lede triticale is gemaak vanaf die F1 van 'n kruising tussen 'n Russiese koringluis-weerstandbiedende rog, 'Turkey 77', en die koringkultivar 'Chinese Spring'. Die alloplo"led is gekruis met gewone broodkoring en met 'Imperial' rog/'Chinese Spring' disomiese addissielyne. Die F2 nageslag vanaf hierdie kruisings is getoets vir Russiese koringluisweerstandbiedendheid en C-bande is ook gedoen. Weerstand is gevind wat geassosieer is met die 1RS chromosoomarm van 'Turkey 77'. Hierdie oorspronklike werk is deur MARAIS (1991) gedoen en uit sy materiaal is 'n monotelosomiese 1RS ('Turkey 77') addissieplant beskikbaar gestel vir die huidige studie. Die F3 nageslag van hierdie monotelosomiese addissieplant is gebruik om die weerstand teen die Russiese koringluis op chromosoom 1RS te bevestig. Die monotelosomiese addissieplant is ook gekruis met die koringkultivar 'Gamtoos' wat die 1BL.1 RS-translokasie dra. Hoewel die 1RS segment van 'Gamtoos' die roesweerstandsgene, Sr31 en Lr26 uitdruk, is dit nie die geval met die 'Turkey 77' 1RS telosoom nie. Hierdie gene kon dus as merkergene gebruik word. Vanuit die F1 is 'n monotelosomiese 1RS addissieplant geselekteer wat ook heterosigoties was vir die 1BL.1 RStranslokasie. Hierdie plant is getoetskruis met 'n luisvatbare gewone broodkoring, 'Inia 66'. Meiotiese paring tussen die rogarms het daartoe gelei dat vyf euplo"lede Russiese koringluis-weerstandbiedende nageslag uit 99 euplo"lede nageslag geselekteer kon word. Een rekombinant het ook Sr31 en Lr26 behou en is toegelaat om self te bestuif. Met behulp van SDSPAGE profiele is Russiese koringluis-weerstandbiedende 1BL.1 RStranslokasie homosigote ge"ldentifiseer en kon bevestig word dat die weerstandsgeen vir die Russiese koringluis oorgedra is na die 1BL.1 RS ('Veery') -translokasie. Twee strategies is gevolg om die Russiese koringluislokus of -loci te karteer: (1) 'n Telosomiese analise is gedoen. 'n Plant met 2n = 40 + 1BL.1 RS + 1RS is verkry en met 'n luisvatbare koring bestuif. (2) 'n Gerekombineerde, disomiese plant met Russiese koringluis-weerstandbiedendheid maar sonder die Lr26 en Sr31 allele is gekruis met 'Gamtoos' en die F1 getoetskruis. Die toetskruisouer in beide die strategiee was 'Chinese Spring'. In die eerste eksperiment is die Sr31-lokus 10.42 kaarteenhede vanaf die Lr26-lokus gelokaliseer. Die raesdata het ge"impliseer dat onbetraubare genetiese kaarteenhede geskat sou word en daarom is die omslagtige Russiese koringluis weerstandsbepalings nie gedoen nie. In die tweede eksperiment is die Russiese koringluis-weerstandsgeen op 14.5 kaarteenhede vanaf die Lr26-lokus gelokaliseer. Nie-Mendeliese segregasie van die Russiese koringluis-weerstand in hierdie karteringseksperiment het ge'impliseer dat die berekende kaartafstand onakkuraat mag wees. Dit was ook nie moontlik om op grand van die data die aantal gene betrakke af te lei nie.
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Zilkens, Matthias. "Towards sustainability of wheat and maize cultivation in Beijing region : economic performance and environmental impacts /." Aachen : Shaker, 2004. http://www.gbv.de/dms/zbw/500401152.pdf.
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Malik, Tanwir Ahmad. "Genetics and breeding for drought resistance in wheat : physio-molecular approaches." Thesis, Bangor University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282261.
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Sardana, Ravinder Kumar. "Structure and control of expression of ribosomal RNA genes in wheat." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305819.
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Jackson, Stephen Derek. "Proteins that bind to the promoter region of wheat rRNA genes." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334105.
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Noori, Seyed Ahmad Sadat. "Salinity tolerance in wheat (Triticum aestivum L.) and its relatives." Thesis, University of Liverpool, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367305.
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Zainuddin. "Genetic transformation of wheat (Triticum aestivum L.)." Title page, Contents and Abstract only, 2000. http://web4.library.adelaide.edu.au/theses/09APSP/09apspz21.pdf.
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Bibliography: leaves 127-151. The successful application of genetic engineering in wheat is dependent on the availability of suitable tissue culture and transformation methods. The primary object of this project was the development of these technologies using elite Australian wheat varieties.
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Green, Andrew Justin. "Yield Improvement in Eastern Soft Red Winter Wheat from 1919 to 2009." Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/36086.
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Periodic evaluation of improvements in yield and disease resistance is necessary to assess breeding progress over time, and the elucidation of underlying traits responsible for yield gains can help direct future breeding. Objectives of this study were: 1) to determine the rate and magnitude of yield progress in eastern soft red winter (SRW) wheat (Triticum aestivum, L.) cultivars released from 1950 to 2009 relative to a historical cultivar Red May (1919) and; 2) to determine effects of leaf rust (Puccinia triticina f. sp. tritici) and powdery mildew [Blumeria graminis (DC.) E.O. Speer f. sp. tritici Em. Marchal] on grain yield components and agronomic traits. Replicated yield trials were grown at Warsaw, VA in 2010 and 2011, and at Holland and Blacksburg, VA in 2011. For objective 1, the genetic progress experiment: flag leaf angle, kernel weight, spikes m-2, lodging, flowering date and harvest index collectively explained the most yield variation in multiple environments on the basis of linear regression analysis. Rate of genetic yield improvement ranged from 0.56% yr-1 at Holland in 2011 to 1.4% yr-1 at Blacksburg in 2011. For objective 2, the disease loss experiment: yield losses ranged from 1% at Holland in 2011 to 21% at Warsaw in 2011. Losses primarily due to powdery mildew and leaf rust were as high as 14% and 33%, respectively. Powdery mildew had the largest negative correlation with harvest index and seeds spike-1, while leaf rust had the largest negative correlation with plant biomass and harvest index.Master of Science
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Atty, Nicholas Martin. "Isolation of cloned DNA sequences encoding wheat ribosomal proteins by immunological methods." Thesis, University of Leeds, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329973.
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Forde, Janice. "The molecular biology of the high molecular weight glutenin subunits of wheat." Thesis, Rothamsted Research, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.352836.
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Taeb, Mohammad. "The genetics of salt and waterlogging tolerance in wheat (Triticum aestivum L.)." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239092.
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Mheni, Nafeti Titus. "Association Analysis and Genome-wide Selection for Early Maturity in Wheat." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1417703279.
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Bernier, Anne-Marie. "Genetics and linkage analysis of grain dormancy and tyrosinase in wheat." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ31966.pdf.
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Hague, Rachel Elise. "Genetics of quantitative resistance to powdery mildew in Fenman winter wheat." Thesis, University of East Anglia, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267461.
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Forsyth, Sally Ann. "The biochemical and molecular genetics of some seed proteins of wheat." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314995.
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Sood, Shilpa. "Molecular characterization of threshability genes in wheat." Diss., Manhattan, Kan. : Kansas State University, 2008. http://hdl.handle.net/2097/1083.
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Singh, Nagendra Kumar. "The structure and genetic control of endosperm proteins in wheat and rye." Title page, contents and abstract only, 1985. http://web4.library.adelaide.edu.au/theses/09PH/09phs6174.pdf.
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Groenewald, Johannes Zacharias. "Tagging and mapping of prominent structural genes on chromosome arm 7DL of common wheat." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52474.
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Thesis (PhD (Agric)) -- Stellenbosch University, 2001.ENGLISH ABSTRACT: Chromosome arm 7DL of common wheat carries genes for agronomically important traits such as leaf rust, stem rust, Russian wheat aphid and eye spot resistance. Some of these genes occur on introgressed foreign chromatin, which restricts their utility in breeding. The 7DL genetic maps are poorly resolved, which seriously hampers attempts to manipulate the genes and introgressed regions in breeding. This dissertation represents an attempt to improve our knowledge of the relative map positions of three resistance genes that have significant potential for use in local breeding programmes. The leaf rust resistance gene, Lr19, is located on a Thinopyrum ponticum-derived translocation which occupies a large part of the terminal end of 7DL. The translocation also carries genes for less favourable traits such as yellow flour colour. Attempts have been made to reduce the size of the translocation through allosyndetic pairing induction; the primary aims being to remove deleterious genes and to minimise the amount of foreign chromatin associated with Lr19 so it can be recombined with other useful 7DL genes. Twenty-nine 'Indis'-derived Lr 19 deletion mutants were previously produced by gamma irradiation and a physical map was constructed. In this study, the set of mutant lines were further analysed using 144 Sse8387I/Msei and 32 EcoRI/Msel amplified fragment length polymorphism (AFLP) primer combinations. The previous physical map, which was based on five restriction fragment length polymorphism (RFLP) markers and five structural gene loci, was extended and now includes 95 novel AFLP markers (86 Sse8387I/Msei and 9EcoRI!Msel markers), of which seven map close to Lr 19. Most of the deletions could be ordered according to size and the improved map has already been used to characterise shortened recombinant forms of the Lr 19 translocation. An unsuccessful attempt was made to convert one of the seven markers closest to Lr 19 into a sequence-specific marker. However, an AFLP marker located distally from Lr 19 was successfully converted into a sequence-specific marker in collaboration with other researchers. An attempt was also made to map and tag the Russian wheat aphid (RWA) resistance gene, Dn5. A doubled haploid mapping population consisting of 94 lines was created and typed for Dn5, four microsatellite loci and the endopeptidase locus, Ep-Dl. The Dn5 locus mapped 25.4 cM and 28.6 cM distally from Xg.vm111 and Xg.vm437, respectively, but was not linked to Xgwm428, Xgwm3 7 or Ep-Dl. Tagging of Dn5 was attempted by screening twelve homozygous resistant and seven homozygous susceptible F2 lines from a cross between 'Chinese Spring' and 'PI 294994' with 70 Sse8387IIi\1sei AFLP primer combinations. Only two potentially useful polymorphisms (one in coupling and one in repulsion phase) were identified. Conversion of the coupling phase marker to a sequence-specific marker was not successful. The eyespot resistance gene, Pchl , was derived from Triticum ventricosum and is present in the wheat VPM-1. Close association between Pchl and the endopeptidase Ep-Dlb allele has been reported previously. Pchl/Ep-Dl was tagged by screening ten wheat genotypes (each homozygous for the confirmed presence or absence of Pchl and/or Ep-Dl b) with 36 Sse83 87I/ Msei AFLP primer combinations. Three AFLP markers were closely associated with Pchl I Ep-D 1, one of which was targeted for conversion into a sequence-specific marker. The sequence-specific marker contained a microsatellite core motif and was found to be useful for tagging Pchl!Ep-Dl. A genetic distance of 2 cM was calculated between the novel microsatellite marker and Ep-Dl. The microsatellite marker was also polymorphic for the Lr 19 translocation and it was possible to map it between the Wsp-Dl and Sr25 loci. In this dissertation, mapping and/or tagging of three important resistance genes were achieved. Due to the fact that all markers used in these studies were not polymorphic between all of the targeted regions, it was not possible to fully integrate the data obtained for the three regions.
AFRIKAANSE OPSOMMING: Chromosoom arm 7DL van broodkoring dra gene vir agronomies-belangrike kenrnerke soos blaarroes, stamroes, Russiese koringluis en oogvlek weerstand. Sommige van hierdie gene kom voor in blokke spesie-verhaalde chromatien wat hul bruikbaarheid in teling beperk. Die genetiese kaarte van 7DL is swak ontwikkel en dit maak dit baie moeilik om hierdie gene en spesie-verhaalde streke tydens teling te manipuleer. Hierdie proefskrif verteenwoordig 'n paging om kennis van die relatiewe kaart liggings van drie weerstandsgene, met betekenisvolle potensiaal in plaaslike tee! programme, te verbreed. Die blaarroes weerstandsgeen, Lr 19, kom voor op 'n Thinopyrum ponticum-verhaalde translokasie wat 'n groot terminale gedeelte van 7DL beslaan. Die translokasie dra ook gene vir minder gewensde kenrnerke soos gee! meelkleur. Pogings is aangewend om die translokasie deur homoeoloe parings-induksie te verkort. Die doe! was om nadelige gene te verplaas en die hoeveelheid vreemde chromatien geassosieer met Lr 19 te minimiseer sodat dit met ander nuttige gene op 7DL gerekombineer kan word. Nege-en-twintig 'Indis'-verhaalde Lr 19 delesie mutante is vroeer met gamma bestraling geproduseer en gebruik om 'n fisiese kaart op te stel. Teenswoordig is die stel mutante verder ontleed met behulp van 144 Sse8387I!Msei en 32 EcoRII Msel amplifikasie-fragment-lengte-polimorfisme (AFLP) inleier kombinasies. Die bestaande fisiese kaart, wat gebaseer was op vyf restriksie-fragment-lengte-polimorfisme (RFLP) merkers en vyf strukturele geen loki, is uitgebrei en sluit nou 95 unieke AFLP merkers (86 Sse8387I/Msel en 9EcoRI/Msel merkers) in, waarvan sewe naby aan Lr19 karteer. Die meeste van die delesies kon op grond van hulle grootte gegroepeer word en die verbeterde fisiese kaart is alreeds gebruik om verkorte rekombinante vorms van die Lr 19 translokasie te karakteriseer. 'n Onsuksesvolle paging is aangewend om een van die sewe merkers naaste aan Lr 19 om te skakel na 'n volgorde-spesifieke merker. 'n AFLP merker wat distaal van Lr 19 karteer is egter wel suksesvol in samewerking met ander navorsers omgeskakel na 'n volgordespesifieke merker. 'n Paging is ook aangewend om die Russiese koringluis (RKL) weerstandsgeen, Dn5, te karteer en merkers gekoppel aan die geen te identifiseer. 'n Verdubbelde-haplo!ede karteringspopulasie van 94 lyne is geskep en getipeer vir Dn5, vier mikrosatelliet loki en die endopeptidase lokus, Ep-D1. Die Dn5 lokus karteer 25.4 cM en 28.6 cM distaal van Xgwml11 en Xgwm437, respektiewelik, maar was me gekoppel met Xgwm428, Xgwm37 of Ep-D1 me. Twaalf homosigoties weerstandbiedende en sewe homosigoties vatbare F2 lyne uit die kruising: 'Chinese Spring' I 'PI 294994' is met 70 Sse8387VMsel AFLP inleier kombinasies getoets in 'n poging om merkers vir Dn5 te identifiseer. Slegs twee moontlik bruikbare polimorfismes (een in koppelings- en een in repulsie fase ), is ge'identifiseer. Omskakeling van die koppelingsfase merker na 'n volgorde-spesifieke merker was onsuksesvol. Die oogvlek weerstandsgeen, Pch1, is uit Triticum ventricosum oorgedra en kom voor in die koringlyn, VPM-1. Noue koppeling van Pch1 en die endopeptidase alleel, Ep-D1 b, is vantevore gerapporteer. Merkers is vir P chl I Ep-D 1 gevind deur tien koring genoti pes ( elkeen homosigoties vir die bevestigde teenwoordigheid of afwesigheid van Pch1 en/of Ep-D1 b) te toets met 36 Sse83871/kfsel AFLP inleier kombinasies. Drie AFLP merkers is gevind wat nou koppel met Pchl!Ep-D1 , waarvan een gekies is vir omskakeling na 'n volgorde-spesifieke merker. Die volgorde-spesifieke merker het 'n mikrosatelliet kernmotief bevat en was nuttig as merker vir Pch1/Ep-D1. 'n Genetiese afstand van 2 cM is tussen die unieke mikrosatelliet merker en Ep-D1 bereken. Die mikrosatelliet merker was ook polimorfies vir die Lr 19 translokasie en dit is tussen die Wsp-D1 en Sr25 loki gekarteer. Kartering en/of identifikasie van merkers vir drie belangrike weerstandsgene was suksesvol in hierdie studie. Omdat al die merkers wat gebruik is, nie polimorf was tussen al die streke van belang nie, was dit nie moontlik om die data vir elk van die drie streke ten volle te integreer nie.
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Woodend, John J. "Genetic and physiological studies on potassium and nitrogen uptake and utilization in wheat." Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/27653.
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Experiments were undertaken to examine the extent of variation for potassium and nitrogen uptake and utilization in wheat and also to address some issues of relevance to the improvement of these traits. These issues included the inheritance of these traits and the difficulties that could arise due to (1) the methodology that is used to measure ion fluxes and utilization, (2) ontogenetic variation in the expression of these traits, and (3) the growth stage at which nutrient utilization is evaluated. To compare varieties developed during different periods in the history of wheat breeding, the varieties were assigned to five groups on the basis of height and origin.
Nutrient fluxes were measured either as average net fluxes or short-term net fluxes. Nutrient utilization was expressed as shoot fresh weight per plant, efficiency ratio or utilization efficiency.
Substantial variation was observed for all traits except potassium and nitrogen efficiency ratios. Although short-term net potassium fluxes were negatively correlated with root potassium concentration, some of the differences in flux were not associated with differences in root potassium concentration. These differences must therefore be heritable. Due to the complexity of the regulation of nitrate uptake, genotypic differences in short-term net nitrate flux were not examined in relation to root nitrate concentration. Therefore, some of the variation in nitrate flux could be due to differences in root nitrate concentration or some other factor(s) which regulates nitrate uptake.
Significant differences between groups were also observed. The tall varieties had the highest potassium and nitrate fluxes but were not significantly different from the triple dwarfs. The double dwarfs were the poorest performers for both nutrient uptake and utilization. In general, the tall traditional varieties were more vigorous and hence showed the highest shoot weight per plant and utilization efficiencies. These findings are examined in relation to the contention that plant breeding under high fertility conditions may have resulted in a decline in the ability of plants to acquire and utilize mineral nutrients.
The inheritance of short-term net potassium flux, shoot weight per plant, potassium efficiency ratio and potassium utilization efficiency was studied in four crosses. Complex modes of inheritance were observed for all the traits. For one of the crosses significant reciprocal effects were observed for shoot weight per plant, efficiency ratio and utilization efficiency. Narrow sense heritabilities for the two traits most likely to be selected for, namely short-term net potassium flux and shoot weight per plant, indicated that selection for these traits should be carried out amongst families rather than amongst single plants. Diallel analysis for nitrate uptake and utilization indicated that both additive and dominance gene effects are important in the determination of these traits.
The effect of developmental changes in potassium uptake and utilization on varietal comparisons and genetic studies was investigated by comparing the performance of six varieties at different stages of growth over a five-week period. The rankings of the varieties for short-term net potassium flux and shoot weight per plant were found to be fairly consistent. Correlations between average net fluxes for different time periods as well between short-term and average net fluxes were poor. These findings indicate that selection for differences in uptake should be based on fluxes obtained from solutions identical in concentration to the growth solution rather than on perturbation fluxes obtained by depletion of a solution much more concentrated than the growth solution.
All measures of potassium utilization based on vegetative growth were poorly correlated with performance at the adult stage. Significant negative rank correlations between shoot fresh weight per plant and grain weight per plant were obtained most likely due to differences in harvest index. This finding casts some doubt on the usefulness of vegetative measures of nutrient utilization as indicators of nutrient-use efficiency for a crop in which the economic product consists of grain.Science, Faculty of
Botany, Department of
Graduate
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Neves, Nuno Alberto Fernandes Ferreira Neves. "Genomic interactions in wheat-rye hybrids : nucleolar dominance, DNA methylation and chromatin topology." Thesis, University of East Anglia, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317976.
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Willey, D. L. "Structure and expression of the gene for cytochrome f in pea and wheat." Thesis, University of Cambridge, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.354698.
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Valles, K. L. M. "The use lipophilic ions to measure intracellular membrane potentials in intact wheat protoplasts." Thesis, University of Sussex, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373919.
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Gupta, Ram Bilas. "Low-Molecular-Weight subunits of glutelin in wheat and related species : their characterization, genetics and relation to bread-making quality." Title page, contents and summary only, 1989. http://web4.library.adelaide.edu.au/theses/09PH/09phg977.pdf.
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Khan, Imtiaz Ahmed. "Utilisation of molecular markers in the selection and characterisation of wheat-alien recombiant chromosomes." Title page, contents and summary only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phk451.pdf.
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Bibliography: leaves 137-163. his is a comprehensive study of induced homoeologous recombination along most of the complete genetic length of two homoeologous chromosomes in the Triticeae (7A of common wheat and 7Ai of Agropyron intermedium), using co-dominant DNA markers. Chromosome 7Ai was chosen as a model alien chromosome because is has been reported to carry agronomically important genes conferring resistance to stem rust and barley yellow dwarf virus on its short and long arms, respectively.