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1

Rees, R. T. "Metabolic activity of isolated Glycine max and Triticum aestivum cells." Thesis, Nottingham Trent University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370504.

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2

Aperavičiūtė, Vaida. "Skirtingų veislių žieminių kviečių (Triticum aestivum L.) laikomų grūdų kokybės rodiklių palyginimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140613_102223-82018.

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Tyrimo objektas žieminių kviečių veislių 'Julius', 'Leifer', 'Operetka' ir 'Skagen' technologinių savybių kitimas laikymo metu. Tyrimo tikslas ištirti skirtingų veislių žieminių kviečių technologinių savybių kitimo dėsningumus priklausomai nuo laikymo trukmės. Uždaviniai 1. Ištirti skirtingų veislių žieminių kviečių grūdų kokybę tik nuėmus derlių. 2. Įvertinti laikomų grūdų kokybę. 3. Apibendrinti grūdų technologinių savybių kitimo dėsningumus. Tyrimo metodai 2012–2013 m. Pakruojo rajone buvo auginti kviečiai. Žieminių kviečių derlius nuimtas 2013 m. rugpjūčio 20 d. Atlikti kviečių kokybės rodiklių tyrimai. Standartiniais metodais ištirta: grūdų drėgnis, baltymų, šlapiojo glitimo, krakmolo kiekis, sedimentacijos rodiklis, kritimo skaičius, piltinis tankis, pesticidų likučiai. Vėliau kviečių mėginiai laikomi Diliauskų elevatoriuje, sandėlyje dėžutėse po 4 kg, trimis pakartojimais. Kas mėnesį atliekami kviečių rodiklių kokybės tyrimai. Tyrimo rezultatai. Žieminių kviečių auginimo agrotechnikoje naudojant pesticidus pagal rekomendacijas ir prisilaikant leidžiamų normų, pesticidų likučiai grūduose nesikaupia. Laikant sausus grūdus sandėlyje jų drėgmė padidėja, baltymų kiekis ir saiko svoris nesikeičia. Glitimo kiekis laikomuose žieminiuose kviečiuose padidėjo nežymiai. Krakmolo kiekis laikomuose žieminiuose kviečiuose didėjo vidutiniškai 1,3 %. Laikymo laikotarpiu sedimentacijos vertės žieminiuose kviečiuose mažėjo, vidutiniškai 6,45 ml. Kritimo skaičius turėjo tendensiją... [toliau žr. visą tekstą]
Research object winter wheat varieties 'Julius', 'Leifer', 'Operetka' and 'Skagen' technological characteristics change during storage. Research aim explore the different varieties of winter wheat technological properties change dependent on the storage time. Objectives 1. First investigate the different varieties of winter wheat grain quality after the harvest. 2. Evaluate the quality of stored grain. 3. Summarize the technological properties of grain variation patterns. Research methods 2012-2013 year Pakruojo area were grown winter wheat. Winter wheat harvested in 2013 August 20 d. Perform quality in wheat research. Analyzed by standard methods of grain moisture content, protein, wet gluten, starch content, sedimentation value, falling number, bulk density, pesticide residues. Winter wheat samples kept in Diliauskų elevators, stock boxes of 4 kg, with three replications. Monthly indicators made of wheat quality tests. Research results. Winter wheat agricultural equipment, the use of pesticides in accordance with guidelines and in compliance with the allowable limits of pesticide residues in grain accumulation. Keeping dry grain stock of humidity increases the protein content moderation and weight does not change. Gluten content stored in winter wheat increased slightly . The starch content is stored in winter wheat increased an average of 1, 3 % . The storage period of sedimentation values in winter wheat decreased an average of 6, 45 ml . Falling number was... [to full text]
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3

Cosser, Nicola. "Genotype and systems interactions on grain yield and quality for organic wheat (Triticum aestivum) production." Thesis, University of Reading, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320192.

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4

Wessels, Pieter Gerhardus Wilhelmus. "Soil nitrogen dynamics and spring wheat (Triticum aestivum) production in different cropping systems in the Swartland." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52455.

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Thesis (MScAgric)--University of Stellenbosch, 2001.
ENGLISH ABSTRACT: Protein and oilseed production in the winter rainfall region of South Africa (primarily the Southern and Western Cape) is well below the potential for the area. One possible method of increasing production is to convince producers that the inclusion of protein and oilseed rotational crops will enhance the sustainability of wheat production systems. A project to investigate, quantify and elucidate the effect of canola (Brassica napus), lupins (Lupinus angustifolius) and medics (Medicago spp.) on subsequent wheat (Triticum aestivum) production as well as their influence on soil fertility in respect to nitrogen was initiated in 1999. The long- term rotational crop system experiment on Langgewens experimental farm near Malmesbury, provided the infrastructure for the project. During the 1999 and 2000 wheat-growing seasons, 50m2 plots were demarcated in wheat fields where wheat, lupins, canola or medics were produced in 1998 and 1999 respectively. Each plot was cleared of all vegetation and received no fertilizer N. In these fallow plots, soil samples were collected at three to four week intervals and the available nitrate-N and ammonium-N content of the topsoil (0-15cm depth) and the subsoil (15-30cm depth) were determined. Additional soil samples were also taken from the topsoil on 09/03/2000 after a summer fallow period. These samples were taken on plots that were subjected to a wheat crop in 1999, but were preceded by either wheat, canola, lupins or medics in 1998. The soil samples were then subjected to a 60-day incubation period at 15°C while being maintained at 75% of their water holding capacity. Mineral N was determined after 0, 3, 7, 15, 30, 45 and 60 days of incubation. Large variation in the nitrogen contents observed made it difficult to always obtain significant differences. The results of the soil investigations however indicate that the inclusion of lupins and medics in wheat cropping systems in the Swartland could help to limit the decline of mineral N in the soil profile, experienced within a growing season. This will therefore enable farmers to reduce fertilizer inputs without facing soil mineral N depletion. Plant samples were also collected from wheat plots during the 1999 growing season on three occasions (23/06/99 (growth stage 5), 5/08/99 (growth stage 15), 14/09/99 (growth stage 23)). Plots were selected to represent the same treatments as in the soil sampling procedure during the growing season of 1999 as described above. Plant and tiller numbers of a 0.25m2 sub sample from each plot were counted and leaf area was determined, whereafter the dry material was weighed. The percentage nitrogen content in the leaves and stems were subsequently determined using Near Infra-Red Spectroscopy. In terms of vegetative growth, little difference was observed. A significant increase in nitrogen content of wheat plants growing in plots where wheat and canala were grown in 1998 was observed in the second plant sampling (growth stage 15) and this was attributed to higher nitrogen topdressing. However, on the third sampling date on 14/9/1999 (growth stage 23), the difference was no longer evident. The most important conclusion to make from this study, is that farmers can probably save on fertilizer inputs when including lupins and medics in their wheat production systems, without risking poorer wheat growth. At growth stage 28, a 0.25m2 sub sample of wheat plants was removed at a randomly chosen point in each of the plots described above. Ears and grains were subsequently counted. The wheat remaining on the plots were then harvested at the end of October 1999 using a plot combine. Subsequently the yield, hectolitre mass, thousand grain mass and % crude protein was determined from samples of harvested grain from each plot. The % flour and % bran extraction were then determined whereafter the % flour protein was determined. Micro bread loafs were baked to estimate the loaf volume. Flour and dough properties were also tested using the Falling Number System, mixograph and alveograph. Wheat in cropping systems consisting of legume phases such as lupins and medics, required less nitrogen fertilizer application to achieve statistically the same yield, flour and dough properties. These crop rotations can therefore be considered as more ecologically sustainable and economically viable for the Swartland. This study was aimed at determining the effect of different crop rotations on soil fertility, and because clear soil fertility trends take time to form, this study was probably too short to obtain fully significant differences.
AFRIKAANSE OPSOMMING: Proteïen- en oliesaad produksie in die winter reënval streek van Suid Afrika (hoofsaaklik die Suid- en Weskaap) is ver benede die potensiaal vir die streek. Een moontlike manier om die produksie hiervan te verhoog is om produsente in hierdie streek te oortuig dat die insluiting van proteten en oliesaad gewasse die volhoubaarheid van koring verbouingstelsels sal verhoog. Na aanleiding hiervan, is In projek in 1999 van stapel gestuur om die effek van canola (Brassica napus), lupiene (Lupinus angustifolius) en medies (Medicago spp.) op daaropvolgende koring (Triticum aestivum) produksie, asook die invloed daarvan op grondvrugbaarheid in terme van stikstofinhoud, te ondersoek. Die langtermyn wisselbouproef op Langgewens proefplaas naby Malmesbury, het as infrastruktuur vir die ondersoek gedien. Gedurende die 1999 en 2000 koring groeiseisoene is 50m2 plotte in koringkampe gekies waarop koring, canola, lupiene en medies geproduseer is in onderskeidelik 1998 en 1999. Hierdie plotte is skoon gehou van plantegroei en het ook geen stikstof in kunsmisvorm gekry nie. Met drie tot vier week intervalle is grondmonsters op hierdie plotte versamel in die bogrond (0-15cm diep) en ondergrond (15-30cm diep), waarna die beskikbare nitraat-N en ammonium-N konsentrasie bepaal is. Adissionele grondmonsters van die bogrond is ook geneem op 9/03/2000 na In somer braak periode. Hierdie monsters was geneem op persele wat blootgestel was aan In koringproduksie in 1999, maar voorafgegaan is deur koring, canola, lupiene en medies in 1998. Hierdie monsters is dan vir 60 dae geïnkubeer teen 15°C en 75% van die grond se water houvermoeë. Minerale N inhoud bepalings is gedoen na 0, 3, 7, 15, 30, 45 en 60 dae van inkubasie. Groot variasie in die minerale stikstof inhoud, het die verkryging van herkenbare tendense en konstante statistiese verskille belemmer. Die resultate wat verkry is dui egter dat die insluiting van lupiene en medies in koring produksie stelsels in die Swartland, hoër minerale N vlakke in die grond handhaaf en dit kan boere gevolglik in staat stelom kunsmis insette te besnoei sonder dat grondvrugbaarheid verswak. Op 23/06/99 (groeistadium 5), 5/08/99 (groeistadium 15) en 14/09/99 (groeistadium 23) is plantmonsters versamel van koringpersele. Hierdie persele is gekies om die behandelings van die grondmonsterontledings soos hierbo beskryf, te verteenwoordig. Plante en halms van 'n 0.25m2 area uit die persele is getel en die blaaroppervlaktes is bepaal, waarna die droëmateriaal massa van die area bepaal is. Die persentasie stikstofinhoud van die blare en stingels was daarna bepaal. In terme van vegetatiewe groei was daar nie groot verskille te bespeur nie. Betekenisvolle hoër stikstof inhoud van koringblare in plotte waar daar in die vorige jaar canola en koring verbou was, is in die tweede planttrekking (groeistadium 15) gevind en dit is toegeskryf aan die hoër stikstof kopbemesting wat daardie behandelings ontvang het. Teen die derde monsterneming op 14/09l99 (groeistadium 23), was hierdie verskille nie meer in die ontledingsdata te sien nie. Die afleiding wat van hierdie studie gemaak is, is dat boere moontlik stikstofbemesting kan verminder as hulle lupiene en medies in hulle koring produksiestelsels inbring, sonder om die risiko van swakker groei te verhoog. Op 20/10/99 (groeistadium 28) is 0.25m2 plante van elke koringperseel verwyder waarna die are en die korrels getel is. Die koring wat nog op die persele was is teen die einde van Oktober 1999 met 'n perseelstropertjie geoes. Opbrengs, hektoliter massa, duidendkorrel massa en % ru-proteïene is daarna bepaal. Volgende is die % meel en % semel ekstraksie bepaal waarna die % meelproteïene bepaal is. Mikro broodjies is ook gebak om die broodvolume te bepaal. Meel en deeg eienskappe is ook getoets met die Falling Number System, mixogram en alveogram. Koring in produksiestelsels met peulplant fases (lupien en medies in hierdie geval), het minder N toediening nodig gehad om statisties dieselfde opbrengs, meel- en deeg eienskappe te verkry. Lupien en medic gebaseerde wisselbou praktyke in die Swartland kan gevolglik as meer ekologies volhoubaar en ekonomies haalbaar bestempelword. Hierdie studie het gepoog om die invloed van wisselbou op grondvrugbaarheid te ondersoek. Sodanige veranderings neem egter tyd en daarom is dit waarskynlik nog te gou om werklike grondvrugbaarheids verskille waar te neem.
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5

Vincent, Jonathan. "Inférence des réseaux de régulation de la synthèse des protéines de réserve du grain de blé tendre (Triticum aestivum L.) en réponse à l'approvisionnement en azote et en soufre." Thesis, Clermont-Ferrand 2, 2014. http://www.theses.fr/2014CLF22485/document.

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La teneur et la composition en protéines de réserve du grain de blé tendre (Triticum aestivum L.) sont les principaux déterminants de sa valeur d’usage et de sa qualité nutritionnelle. La composition en protéines de réserve du grain est déterminée par la teneur en assimilâts azotés et soufrés par grain via des lois d’échelle qui pourraient être les propriétés émergentes de réseaux de régulation. Plusieurs facteurs de transcription intervenant dans cette régulation ont été mis en évidence, mais les voies et mécanismes impliqués sont encore très peu connus. Le constat est identique en ce qui concerne l’impact de la nutrition azotée et soufrée sur ce réseau de régulation. Le développement des outils de génomique fonctionnelle et de bioinformatique permet aujourd’hui d’aborder ces régulations de manière globale via une approche systémique mettant en relation plusieurs niveaux de régulation. L’objectif du travail présenté est d’explorer les réseaux de régulation –omiques impliqués dans le contrôle de l’accumulation des protéines de réserve dans le grain de blé tendre et leur réponse à l’approvisionnement en azote et en soufre. Une approche d’inférence de réseaux basée sur la découverte de règles a été étendue, implémentée sous la forme d’une plateforme web. L’utilisation de cette plateforme a permis de définir des sémantiques multiples afin d’inférer dans un cadre global, des règles possédant différentes significations biologiques. Des facteurs de transcription spécifiques de certains organes et certaines phases de développement ont été mis en évidence et un intérêt particulier a été apporté à leur position dans les réseaux de règles inférés, notamment en relation avec les protéines de réserve. Les travaux initiés dans cette thèse ouvrent un champ d’investigation innovant pour l’identification de nouvelles cibles de sélection variétale pour l’amélioration de la valeur technologique et de la qualité nutritionnelle du blé. Ils devraient ainsi permettre de mieux maîtriser la composition en protéines de réserve et ainsi produire des blés adaptés à des utilisations ciblées ou carencé en certaines fractions protéiques impliquées dans des phénomènes d’allergénicité et d’intolérance du gluten, ce dans un contexte d’agriculture durable et plus économe en intrants
Grain storage protein content and composition are the main determinants of bread wheat (Triticum aestivum L.) end-use value. Scaling laws governing grain protein composition according to grain nitrogen and sulfur content could be the outcome of a finely tuned regulation network. Although it was demonstrated that the main regulation of grain storage proteins accumulation occurs at the transcriptomic level in cereals, knowledge of the underlying molecular mechanisms is elusive. Moreover, the effects of nitrogen and sulfur on these mechanisms are unknown. The issue of skyrocketing data generation in research projects is addressed by developing high-throughput bioinformatics approaches. Extracting knowledge on from such massive amounts of data is therefore an important challenge. The work presented herein aims at elucidating regulatory networks involved in grain storage protein synthesis and their response to nitrogen and sulfur supply using a rule discovery approach. This approach was extended, implemented in the form of a web-oriented platform dedicated to the inference and analysis of regulatory networks from qualitative and quantitative –omics data. This platform allowed us to define different semantics in a comprehensive framework; each semantic having its own biological meaning, thus providing us with global informative networks. Spatiotemporal specificity of transcription factors expression was observed and particular attention was paid to their relationship with grain storage proteins in the inferred networks. The work initiated here opens up a field of innovative investigation to identify new targets for plant breeding and for an improved end-use value and nutritional quality of wheat in the context of inputs limitation. Further analyses should enhance the understanding of the control of grain protein composition and allow providing wheat adapted to specific uses or deficient in protein fractions responsible for gluten allergenicity and intolerance
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Maia, Aline Rodrigues. "Envelhecimento acelerado e avaliação da qualidade fisiológica de sementes de trigo acondicionadas em diferentes embalagens e armazenadas em ambiente natural em Ibitirama-ES." Universidade Federal do Espírito Santo, 2007. http://repositorio.ufes.br/handle/10/6591.

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O trigo é uma gramínea, cujas sementes apresentam alta germinação. Estes trabalhos tiveram como objetivo estudar a germinação, o vigor e o armazenamento de sementes de trigo. No estudo do envelhecimento acelerado e experimento foi conduzido no delineamento experimental inteiramente casualizado, com quatro repetições de 25 sementes. Foram avaliadas as temperaturas (41, 43, 45ºC) e o período de exposição adequado (zero, 24, 48, 72 e 96 horas) para a avaliação de sementes de trigo da cultivar Aliança. Conclui-se que: o envelhecimento acelerado de sementes de trigo na temperatura de 41 °C e tempos de exposição de 24 e 48 horas são os mais indicados; sob temperatura de 43 °C recomenda -se utilizar 24 horas de exposição das sementes; a temperatura de 45 °C é letal. No capítulo dois com o objetivo de avaliar a qualidade fisiológica das seis cultivares de trigo o experimento foi conduzido em delineamento experimental inteiramente casualizado, com quatro repetições de 50 sementes, em esquema fatorial 6x3x7, sendo seis cultivares de trigo (Timbaúva, CPAC 98308, CPAC 96306, CPAC 9617, Aliança e PF 950407) x três tipos de embalagens (pano, plástico e papel) x sete períodos de armazenamento (zero, dois, quatro, seis, oito, dez e doze meses). No armazenamento, foram avaliados os tipos de embalagens, a emissão da raiz primária com 2 mm de comprimento e o desenvolvimento da radícula para eixos embrionários, em seguida analizou-se a massa seca das plântulas. Conclui-se que: As sementes de trigo da cultivar CPAC 98308 apresenta boa armazenabilidade nas condições do município de Ibitirama; a perda da capacidade germinativa das sementes das seis cultivares se dá após seis meses nas embalagens de pano e papel e aos oito meses na embalagem plástica; a redução da qualidade fisiológica das seis cultivares de trigo tem início a partir do quarto mês de armazenamento nas embalagens de pano e papel e a partir do sexto mês na embalagem plástica; a deterioração foi verificada nas sementes da embalagem de pano aos oito meses, na de papel aos seis meses e na embalagem plástica aos doze meses.
The wheat is a grassy one, whose seeds present high germination. These works had had as objective to study the germination, the vigor and the storage of wheat seeds. In the study of the accelerated aging and experiment casualizado was lead in the completely randomized design, with four replications of 25 seeds. The temperatures (41, 43, 45ºC) and the adequate period of exposition (zero, 24, 48, 72 and 96 hours) for the evaluation of seeds of wheat of cultivating had been evaluated Alliance. One concludes that: with the accelerated aging of seeds of wheat in the Temperature of 41°C for periods of 24 and 48 hours of treatment were the more indicated for the wheat aging; under temperature of the 43°C was recommended 24 hour s of exposition. Treatment of the seeds with accelerated aging using temperature of 45ºC determined the death of the seeds, culminating with deterioration. In chapter two with the objective to evaluate the physiological quality of the six to cultivate of wheat the experiment was lead in experimental completely randomized design, with four repetitions of 50 seeds, in factorial project 6x3x7, being six to cultivate of wheat (Timbaúva, CPAC 98308, CPAC 96306, CPAC 9617, Alliance and PF 950407) x three types of packings (cloth, plastic and paper) x seven periods of storage (zero, two, four, six, eight, ten and twelve months). In the storage, the types of packings, the emission of the primary root with 2 mm of length and the development of radicule for axles had been evaluated embryonic, after that it was analysis dry mass of seedlings. One concludes that: the seeds wheat of cultivating CPAC 98308 present good storage in the conditions of the city of Ibitirama; the loss of the germinative capacity of the seeds of the six after to cultivate if it gives to six months in the packings of cloth and paper and to the eight months in the plastic packing; the reduction of the physiological quality of the seeds of the six to cultivate of wheat has beginning from the sixth month and in the plastic packing; deterioration was verified in the seeds of the cloth packing to the eight months, in the one of paper to the six months and in the plastic packing to the twelve months.
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Abreu, Daniel Carneiro de. "Whole-farm modeling approach to evaluate different crop rotations in organic dairy systems." Universidade Federal de Viçosa, 2014. http://www.locus.ufv.br/handle/123456789/6596.

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Fundação de Amparo à Pesquisa do Estado de Minas Gerais
O mercado de trigo (Triticum aestivum L.) orgânico para produção de pão cresceu em grande magnitude na região da Nova Inglaterra, nos Estados Unidos. Este nicho de mercado representa uma alternativa de renda para os produtores de leite orgânico abastecerem este mercado através do cultivo e colheita de grãos em rotação de cultura na própria fazenda. Objetivou-se com este estudo determinar a sustentabilidade de oito sequências de rotação de cultura (três anos de rotação) durante o período de 25 anos em uma propriedade produtora de leite orgânica bem manejada. Uma fazenda média foi simulada utilizando o modelo computacional Integrated Farm System Model (versão 3.6) para avaliar o efeito da rotação de cultura no desempenho da cultura, impacto ambiental e rentabilidade. As estratégias de rotação incluíram pasto contínuo (azevém e trigo), milho (Zea mays L.) colhido cedo seguido de trigo de inverno (milho-trigo de inverno- pasto), milho seguido de trigo de primavera (milho-trigo de primavera-pasto), pasto em rotação com trigo de inverno (azevém/trigo - trigo de inverno - azevém/trigo), pasto em rotação com trigo de primavera (azevém/trigo - trigo de primavera - azevém/trigo), soja [Glycine max (L.) Merr.] em rotação por trigo de inverno (soja - trigo de inverno - azevém/trigo) e primavera (soja - trigo de primavera - azevém/trigo), milho em cultivo consecutivo (milho - milho - azevém/trigo) e soja seguida de milho (soja - milho - azevém/trigo). O trigo foi colhido em grão e comercializado a preço premium em todos os anos simulados. Em todas as simulações foram cultivados azevém e trigo (Lolium perenne / Trifolium pratense) consorciados no terceiro ano. Em geral, não houve benefício econômico e ambiental na rotação de cultura em comparação o pasto contínuo (monocultivo). Entretanto, entre as rotações de cultura, o cultivo de trigo de inverno deve ser incentivado, particularmente em rotação com a soja, para reduzir o impacto ambiental e aumentar rentabilidade da fazenda.
The market for high-quality organic bread wheat (Triticum aestivum L.) is increasing in New England. This economic niche represents one alternative income for organic dairy producers (if they include wheat in their crop rotation) to supply this market by raising wheat as a cash crop. Our objective was to determine the sustainability to eight crop rotation sequences of 3-yr rotations in a long-term (25-yr) well-managed organic dairy farm. A medium-sized organic dairy farm was simulated with the Integrated Farm System Model (IFSM, version 3.6) to evaluate crop rotation (management) effects on crop performance, environmental impacts and profitability. The cropping strategies included continuous ryegrass/red clover (continuous grass), corn (Zea mays L.) harvested early followed by winter wheat (corn-wwheat-grass), corn followed by spring wheat (corn-swheat-grass), ryegrass/red clover rotated with winter wheat (grass-wwheat-grass), ryegrass/red clover in rotation with spring wheat (grass-swheat-grass), soybean [Glycine max (L.) Merr.] rotated by both winter wheat (soybean-wwheat-grass) and spring wheat (soybean- swheat-grass), corn double cropped (corn-corn-grass) and soybean followed by corn (soybean- corn-grass). Wheat was harvested as a cash crop in all simulated years and sold at a premium price. All rotations were in long rotation with perennial ryegrass/red clover (Lolium perenne / Trifolium pratense) over the 3-yr. In general, there was no economic and environmental benefit to shifting land from continues grass-based production to specified cropping rotations. However, under crop rotation, use of winter wheat should be encouraged, particularly soybean replaced with cash crop wheat, to reduce environmental impact and improve farm profitability.
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Daraja, Yusuf B. "The effects of intercropping, nitrogen and sulphur nutrition on the performance of wheat (Triticum aestivum) and Faba Bean (Vicia faba) in different production systems." Thesis, University of Reading, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.515808.

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9

Freo, Janete Deliberali. "Aplicação de terra de diatomácea e a infestação com Rhyzopertha dominica nas propriedades físico-químicas e tecnológicas de grãos de trigo armazenados no sistema convencional." Universidade Federal de Pelotas, 2010. http://repositorio.ufpel.edu.br/handle/ri/1324.

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Among the many factors that affect the quality of flour, you can highlight the insect infestation, which also reduces the quality of cereal protein gluten weaken, reduce the technological characteristics and health conditions. Although there are studies on the application of diatomaceous earth in wheat grains, the literature does not provide information about the amount of residue that remains after the flour milling wheat. The aim of the study was to evaluate the infestation of Rhyzopertha dominica and the effect of diatomaceous earth on physicochemical and technological properties of grain stored in the conventional system and quantify the residual silicon in wheat flour. The study was conducted with a sample of wheat (Triticum aestivum) cultivar Abalone and diatomaceous earth KeepDry ® brand. In the experiment with Rhyzopertha dominica, the wheat was infested with densities of zero, 4, 24 and 48 insects in each 8 kg of grain and stored for 240 days, under controlled temperature and relative humidity (25 °C and 70 ± 5%, respectively). In the experiment and every 60 days of storage was collected 2 kg of wheat grains of each population and performed laboratory tests. In the experiment with diatomaceous earth, samples of 10 kg of wheat were treated with zero, 2.0 and 4.0 g.kg-1, homogenized and stored in bags of cotton in the temperature of 25 ºC and relative humidity 70 ± 5% every 60 days and made the physicochemical and technological. The experiments were conducted in a randomized design in a factorial 4 x 5 (four x five levels of infestation periods of storage) and 3 x 4 (three doses of diatomaceous earth x storage period) respectively, with three replicates for each treatment. The analysis carried out in wheat grains were moisture, test weight, ash, proteins, lipids and fatty acidity and flour falling number, gluten content, color, alveography, farinograph, bakery and experimental quantification of silicon. The results were analyzed by use of ANOVA and significant models the averages were compared by Tukey test at 5% probability. Was also performed regression analysis between the responses by the use of statistical program Sisvar® Version 5.3. The analysis and graphs of the regression equations were developed with the help of the program Origin® 5.0. The application of diatomaceous earth and the infestation with Rhyzopertha dominica reduce the physicochemical and technological properties of flour from wheat grain stored in the conventional system. The colorimetric method used for the quantitation of silicon and may be suitable for determination of residue of diatomaceous earth in the flour that remains after the milling of wheat grains. Keywords: Triticum aestivum. Storage. Insects. Alveography. Bakery. Silicon.
Dentre os diversos fatores que afetam a qualidade da farinha, pode-se destacar a infestação por insetos, que, além de reduzir a qualidade das proteínas dos cereais debilitam o glúten, reduzem as propriedades tecnológicas e as condições sanitárias. Embora existam trabalhos sobre a aplicação de terra de diatomácea em grãos de trigo, a literatura não apresenta informações sobre a quantidade de resíduo que permanece na farinha após a moagem do trigo. Objetivou-se, com o trabalho, avaliar a infestação com Rhyzopertha dominica e o efeito da aplicação de terra de diatomácea nas propriedades físico-químicas e tecnológicas de grãos armazenados no sistema convencional e quantificar o resíduo de silício na farinha de trigo. O trabalho foi realizado com amostra de grãos de trigo (Triticum aestivum L) do cultivar Abalone e terra de diatomácea marca KeepDry®. No experimento com Rhyzopertha dominica, o trigo foi infestado com densidades populacionais de zero, 4, 24 e 48 insetos em cada 8 kg de grãos e armazenado por 240 dias, em condições controladas de temperatura e umidade relativa (25 oC e 70 ± 5%, respectivamente). Na instalação do experimento e a cada 60 dias de armazenamento foi coletado 2 kg de grãos de trigo de cada densidade populacional e realizado as análises laboratoriais. No experimento com terra de diatomácea, amostras de 10 kg de trigo foram tratadas com zero, 2,0 e 4,0 g.kg-1, homogeneizadas e armazenadas em sacos de algodão, em ambiente com temperatura de 25 ºC e umidade relativa de 70 ± 5% e a cada 60 dias realizadas as análises físico-químicas e tecnológicas. Os experimentos foram conduzidos em delineamento inteiramente casualizado, em arranjo fatorial 4 x 5 (quatro níveis de infestação x cinco períodos de armazenamento) e 3 x 4 (três doses de terra de diatomácea x quatro períodos de armazenamento) respectivamente, sendo realizadas três repetições para cada tratamento. As análises realizadas nos grãos de trigo foram umidade, peso do hectolitro, cinzas, proteínas, lipídios e acidez graxa e na farinha número de queda, teor de glúten, cor, alveografia, farinografia, panificação experimental e quantificação de silício. Os resultados foram analisados através do emprego da ANOVA e nos modelos significativos as médias foram comparadas entre si pelo teste de Tukey a 5% de probabilidade. Também foi realizada análise de regressão entre as variáveis respostas pelo emprego do programa estatístico Sisvar® Versão 5.3. As análises e os gráficos das equações de regressão foram elaborados com o auxílio do programa Origin® 5.0. A aplicação de terra de diatomácea e a infestação com Rhyzopertha dominica reduzem as propriedades físico-químicas e tecnológicas da farinha extraída de grãos de trigo armazenados no sistema convencional. O método colorimétrico empregado para a quantificação de silício é adequado e pode ser indicado para a determinação de resíduo de terra de diatomácea que permanece na farinha após a moagem dos grãos de trigo.
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10

Nteyi, Sinovuyo Mava. "Effects of crop rotation and tillage system on the control of ryegrass (lolium multiflorum X perenne) in wheat (triticum aestivum) in the Swartland production area of South Africa's Western Cape Province." Thesis, Nelson Mandela Metropolitan University, 2013. http://hdl.handle.net/10948/d1020990.

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A major challenge facing agriculture today is to sustain the productivity of agricultural systems with the reduction of weed invasion. The Swartland region in the Western Cape (South Africa) is intensively cropped, producing wheat (Triticum aestivum) as the major crop. As a result of the weedy ryegrass invasion the wheat yield is reduced. In addition, ryegrass has developed resistance to grass herbicides (graminicides). This situation has increased the need to use alternative practices for controlling the invasion of ryegrass in wheat fields. In this regard, crop rotation and tillage systems were proposed as techniques to suppress the ryegrass invasion. This could thus maintain a sustainable long-term wheat production system with less application of herbicides, decreased input costs and increased total grain yield. Against this background, the effects of crop rotation and tillage were determined on ryegrass seedling emergence in a field and shade netting experiment, while seed dormancy was determined in the laboratory. The objectives were to compare the wheat production of two crop rotations with mono-cropped wheat and assess the impact on the ryegrass population in no-till and minimum tillage systems. Analyses of variance on data sets of ryegrass seeds from 2009, 2010 and 2011 were used to determine germination and dormancy percentages in laboratory experiments. The performance of laboratory treatments was evaluated on the basis of germination percentage of seeds. In the field and shade netting experiments, analyses of variance for data from 2007, 2011 and 2012 were used to determine crop rotation x tillage system response. Field and shade netting performance were evaluated on the basis of ryegrass population inhibition and stimulation respectively. Ryegrass seeds from 2009 and 2010 showed higher germination percentages (80 per cent and 73 per cent) than 2011 (42 per cent). Primary dormancy prevented high germination of newly harvested seeds as dormancy release increase with age of the seed. Results of field and shade netting experiments showed stimulation of the ryegrass weed population in wheat monoculture under minimum tillage. However, when wheat was rotated with leguminous crops under both tillage systems (minimum-till and no-till) ryegrass was significantly inhibited. It was concluded that the critical period for weed competition is the first six weeks after planting. Results from this study provide a basis for producers of cereals to make good decisions with regards to timing weed control measures. It is essential to use competitive crop sequences which will inhibit weeds. The challenge is getting this practice adopted and implemented by producers as it will promote conservation agriculture within the region. This study promotes long-term sustainable wheat production systems with an efficient weed management programme that is environmentally friendly using less herbicides within the Swartland region.
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11

Bailey, William Anthony. "Herbicide-based Weed Management Systems for Potato (Solanum tuberosum) and Wheat (Triticum aestivum) and Growth and Reproductive Characteristics of Smooth Pigweed (Amaranthus hybridus)." Diss., Virginia Tech, 2002. http://hdl.handle.net/10919/28578.

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Integrated weed management involves the utilization of weed biology principles to develop effective and economical control strategies. This research involved investigations of herbicide-based weed management programs in potato (Solanum tuberosum L.) and winter wheat (Triticum aestivum L.) as well as investigations of the biological characteristics of smooth pigweed (Amaranthus hybridus), a troublesome species in many crops. Sulfentrazone is an herbicide registered for use in soybean [Glycine max (L.) Merr.] and tobacco (Nicotiana tabacum L.) that may also have potential for use in potato. In field experiments, potato tolerance to preemergence (PRE) applications of sulfentrazone at rates up to 0.21 kg/ha was similar to that from the registered herbicides metribuzin, metolachlor, or metribuzin plus metolachlor PRE. Potato generally did not tolerate sulfentrazone applications to foliage. Sulfentrazone effectively controlled common lambsquarters (Chenopodium album L.) at rates as low as 0.11 kg/ha and also controlled several annual grasses at higher application rates, but was slightly less effective on jimsonweed (Datura stramonium L.) and ineffective on common ragweed (Ambrosia artemisiifolia L.). Potato tuber yield and grade from sulfentrazone PRE applications was similar to yield of potato treated with registered herbicides. Laboratory research was also conducted to determine the mechanism of sulfentrazone selectivity between potato (a tolerant species), common lambsquarters (a sensitive species), and jimsonweed (an intermediate species). After 48 h root exposure to [14C] sulfentrazone, absorption by common lambsquarters was nearly two-fold that of jimsonweed and three-fold that of potato. Both weed species also exhibited nearly a two-fold increase in sulfentrazone translocation from roots to shoots compared to potato. Since the site of action of sulfentrazone, protoporphyrinogen oxidase, is located in shoot tissue, translocation to shoots is essential for sulfentrazone toxicity. Therefore, the proposed primary mechanisms of selectivity between these species are differential root absorption and differential translocation. Experiments were also conducted to investigate the potential of the experimental herbicide AE F130060 03 for Italian ryegrass (Lolium multiflorum Lam.) control in winter wheat. In laboratory research, foliar absorption of AE F130060 03 in Italian ryegrass was at least three times that in wheat. Additionally, herbicide metabolism was greater in wheat, particularly in wheat treated with the herbicide safener AE F107892. In field experiments, AE F130060 03 was as effective as diclofop-methyl for control of diclofop-sensitive Italian ryegrass and more effective than diclofop-methyl and all other herbicides tested for control of diclofop-resistant Italian ryegrass. Although wheat injury from AE F130060 03 was greater than from other herbicides, wheat recovered and yields were not affected. Postemergence AE F130060 03 applications controlled Italian ryegrass from emergence until the end of tillering, but applications made to four- to five-tiller Italian ryegrass resulted in the least amount of new Italian ryegrass emergence following application. To further define the utility of AE F130060 03 in winter wheat, ten wheat cultivars adapted to Virginia were evaluated for tolerance to AE F130060 03. Biomass production between cultivars was not influenced by AE F130060 03 application in the greenhouse, although slight yield decreases due to herbicide application were found in FFR 518, Coker 9663, AgriPro Patton, and VA98W593 under weed-free conditions in the field. Greenhouse, growth chamber, and field experiments were also conducted to investigate growth and seed production of one imidazolinone-susceptible (S) and five -resistant (R1, R2, R3, R4, and R5) smooth pigweed biotypes. Although the S biotype produced more total biomass than four of the five R biotypes, R4 displayed a more rapid growth rate at 3 to 5 wk after planting and a faster germination rate than S and all other R biotypes. Seed production in R4 was similar to S and greater than in all other R biotypes. Early rapid growth in R4 did not translate into increased biomass accumulation compared to S at the conclusion of the experiments.
Ph. D.
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12

MASSON, PHILIPPE. "Contribution a la valorisation des proteines de reserve du ble tendre (triticum aestivum) : isolement et caracterisation partielle de peptides issus de l'hydrolyse enzymatique menagee de gliadines totales et purifiees." Nantes, 1988. http://www.theses.fr/1988NANT2023.

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13

Roslon, Ewa. "Relay cropping of spring barley and winter wheat /." Uppsala : Dept. of Ecology and Crop Production Science, Swedish Univ. of Agricultural Sciences, 2003. http://epsilon.slu.se/a427-ab.html.

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14

Wiesehoff, Marcel. "Teilflächenspezifische Aussaat von Winterweizen /." Hohenheim : Universität Hohenheim, Institut für Agrartechnik, Verfahrenstechnik in der Pflanzenproduktion, 2005. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=015489100&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.

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15

Ben, Salem Moncef. "Etude comparative de la resistance a la secheresse de quelques varietes de ble." Paris 7, 1988. http://www.theses.fr/1988PA077012.

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On montre que la resistance du ble a la contrainte hydrique est associee au maintien d'un nombre d'epis fertiles et d'un nombre de grains par epi eleves, a une petite taille du grain et a une capacite de recuperation elevee. On a evalue les besoins globaus optima en eau a 440 mm et on a montre qu'une mauvaise efficacite de l'utilisation de l'eau peut etre la consequence d'un developpement foliaire surdimensionne. Une production en grains stable en cas de carence hydrique est liee a une photosynthese globale elevee, a de grandes capacites d'accumulation et de mobilisation der reserves glucidiques. Les mecanismes de resistance differant d'une variete a l'autre, on tente de definir un ideotype de ble adapte aux zones arides
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16

Lesage, Véronique. "Contribution à la validation fonctionnelle du gène majeur contrôlant la dureté / tendreté de l'albumen du grain de blé par l'étude de lignées quasi-isogéniques." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2011. http://tel.archives-ouvertes.fr/tel-00697012.

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La dureté du grain de blé est un des paramètres fondamentaux de la texture de l'albumen. Ce caractère, essentiel pour la valeur d'utilisation des farines, est fortement lié à l'absence ou à la modification des puroindolines. Afin de mieux comprendre la fonction biologique de ces protéines dans le grain de blé (Triticum aestivum L.), nous avons étudié à quatre stades de développement du grain la localisation subcellulaire des puroindolines par immunocytochimie et les protéomes dans deux lignées de blé quasi-isogéniques pour la dureté. Dès la fin de la cellularisation de l'albumen, les puroindolines sont localisées sur la face interne des membranes vésiculaires et dans les corps protéiques en formation, structures dans lesquelles s'accumulent les protéines de réserve du grain. L'analyse par AFFFF (Asymmetrical Flow Field-Flow Fractionation) des deux lignées Hard et Soft, qui diffèrent essentiellement par l'absence du gène Pina dans la lignée Hard, a montré une corrélation entre la dureté et la taille des polymères de protéines de réserve. L'analyse protéomique des fractions albumines/globulines et amphiphiles des grains en développement a révélé une augmentation des protéines de la machinerie de repliement et de réponse au stress dans la lignée Hard, par rapport à la lignée Soft. Les deux approches méthodologiques utilisées semblent également mettre en évidence une cinétique de développement du grain raccourcie dans la lignée Hard. Ces observations suggèrent que les puroindolines interagissent avec les protéines de réserve du grain et suivent le même routage cellulaire. Elles pourraient être impliquées dans les mécanismes de repliement et d'assemblage des prolamines.
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17

Singh, Prachi. "Biorational approach for rhyzopertha dominica control in storage system for triticum aestivum." Thesis, 2018. http://eprint.iitd.ac.in:80//handle/2074/8013.

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18

Tufail, Ahmad Fauziah. "Stability and esterification of lutein in bread wheat during post harvest storage in comparison with banana." Thesis, 2013. http://hdl.handle.net/2440/83353.

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Lutein is an important micronutrient for humans as well as being the primary contributor to the pale creamy to yellow colour of bread wheat and durum based products but tends to be unstable against heat and UV light. During post harvest storage of bread wheat grain some of the lutein may be converted to mono- and di-fatty acid esters that appear to be more stable forms of lutein. The aims of the work presented in this thesis were: to study the effects of temperature on lutein esterification; to compare the relative stability of free lutein and lutein esters in grain stored under wide temperatures and conditions; to confirm that esterification is an enzymic process; to examine the genetic control mechanisms; to attempt to identify the enzyme and the endogenous substrate source of fatty acids; and finally to compare esterification in wheat grain with the same process in banana fruit tissues. This study utilised a high lutein, ester forming bread wheat, Triticum aestivum L. cv DM5685*B12, a non-ester forming bread wheat cv Haruhikari and a high lutein durum wheat, Triticum durum L cv Kamilaroi, that like many durum cultivars does not form lutein esters. Reverse phase high pressure liquid chromatography (RP-HPLC) was used to quantify the lutein and lutein ester concentrations. Lutein esterification was strongly favoured by low relative humidity (8% RH) and followed a first order reaction rate. The maximum rate of lutein esterification was at ≈80°C, however the optimum temperature for maximum synthesis with minimum degradation was between 50 and 60°C. No ester synthesis was observed at temperature higher than 120ºC. These data were consistent with an enzyme participating in the esterification reaction. Lutein ester was found to be more stable than free lutein with a substantially longer shelf life at a temperature of 60°C. An attempt to establish a bioassay system to study esterification was only partially successful since only very low levels of esterification were achieved in reconstituted samples. Further investigation would be required to optimise the process. The limited data did provide suggestive evidence that free fatty acids were probably not involved, rather the fatty acids were more likely to be derived from phospholipids via an acyltransferase reaction. A hexane-soluble fraction derived from a non-ester forming durum, Kamilaroi, was the only substrate that in the presence of a crude enzyme extract and free lutein gave a significant formation of lutein ester. As esterification appeared to be was enzymatically controlled, the genetic control of ester synthesis was investigated. Lutein esterification was compared in a series of nullisomic-tetrasomic Chinese Spring lines and a Haruhikari (zero ester)//Sunco/Indis.82 (high ester) doubled haploid population. Lutein esterification was controlled by a locus, designated Lute, located on the short arm of chromosome 7D closely linked with the marker loci gwm295, wPt-1163 and wPt-3727. In addition to wheat, esterification in banana, Musa acuminata Colla cv Cavendish group was also investigated. Compared to wheat, different patterns of esterification were observed in banana during the ripening with ester synthesis occurring in both banana peel and flesh during post harvest ripening. Esterification in banana occurred under higher moisture content than in wheat and offers another tissue model for the study of the esterification mechanism. This thesis contributes valuable new information on the formation and genetic control of lutein ester formation in wheat grain and will be of value to manufacturers of wheat products seeking to retain lutein in end-products for delivery to costumers.
Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2013
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Skelton, Laura Elizabeth. "A comparison of conventional and alternative cropping systems using alfalfa (Medicago sativa) and winter wheat (Triticum aestivum) an agroecosystem analysis /." 2002. http://purl.galileo.usg.edu/uga%5Fetd/skelton%5Flaura%5Fe%5F200212%5Fms.

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20

Nelson, Alison Gail. "Soil microbial communities and grain quality as affected by spring wheat (Triticum aestivum L.) cultivar and grain mixtures in organic and conventional management systems." Phd thesis, 2011. http://hdl.handle.net/10048/1959.

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It may be possible to tailor crop management to encourage diverse soil microbial communities and beneficial microorganisms, and produce high quality food products. Studies were carried out in 2005-2007 to evaluate the impact of spring wheat (Triticum aestivum L.) cultivar choice and crop polycultures on soil microbial communities in organic and conventional systems, and subsequent wheat quality. Five wheat cultivars were grown organically and conventionally to evaluate grain breadmaking quality and micronutrient content and their impact on the soil microbial community. Organic grain yields were roughly half of conventional yields, but quality levels were all acceptable for Canadian Western Hard Red Spring wheat. Measured soil (0-15 cm) microbial profiles (by phospholipid fatty acid analysis) differed between the two management systems, and amongst cultivars in the conventional system. The most recent cultivar in the study, AC Superb, exhibited the highest levels of fungi suggesting that breeding efforts in conventionally managed environments may have resulted in cultivating mycorrhizal dependence in that environment. In general, many of the studied grain micronutrients were greater in the organically grown wheat system, possibly due in part to decreased grain yield and smaller grain size. Maximizing grain micronutrient content through wheat cultivar choice was dependent on management system. The presence of fungi biomarkers appears to have improved uptake of Mn and Cu. Monocultures and polycultures of common annual crops were grown organically and conventionally in 2006-2007. Intercrops exhibited an ability to overyield in an organic system, largely through weed suppression, but intercrops also overyielded in a conventional system where weeds were controlled through herbicides. As intercrop complexity decreased, the instances of improved weed suppression declined. Management systems and wheat cultivars can alter the composition of the soil microbial community. Annual crop polycultures did not alter soil microbial communities in this study, but showed evidence of agronomic benefits in both organic and conventional systems.
Plant Science
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21

Correia, Pedro Miguel Pereira. "Dissecting heat and drought tolerance in wheat and maize using plant systems biology." Doctoral thesis, 2021. http://hdl.handle.net/10451/51915.

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Population growth and climate change pose serious threats to food security. Heat and drought are major abiotic constraints to crop production and their co-occurrence will increase during the cropping season in several regions. However, there is a lack of studies investigating their combined effect in crop physiological and biochemical processes. Aiming to close this gap, two of the main crops were investigated, wheat and maize, under these conditions. In the first results chapter, it is shown that these co-occurring stresses equally affect the photosynthetic efficiency of genotypes adapted to Mexico (Sokoll) and the UK (Paragon). However, Paragon recovered faster upon stress relief due to an increased PSII photoprotection and cytosolic Invertase activity, suggesting that optimal sucrose export/utilization and increased electron transport machinery photoprotection are essential to limit wheat yield fluctuations under these conditions. In the second results chapter, by studying maize genotypes with contrasting drought or heat tolerance, it was observed that limited transpiration under high temperature allowed water saving upon deficit without decreasing photosynthetic efficiency. This was sustained by higher phosphorylated PEPC and electron transport rate. Limited transpiration rate and synchronized regulation of the C4 carbon assimilation metabolism showed to be key traits for drought and heat tolerance in maize. In the third results chapter, by screening ten wheat genotypes with different tolerance to drought or heat, it was observed that leaf temperature and evapotranspiration expressed significant genotype-environment interactions. Low leaf number and transpiration efficiency were essential to balance water-saving strategies and biomass production. Changes in the carbohydrate (cytosolic Invertase, Hexokinase, Phosphofructokinase) and antioxidant metabolism (Peroxidases, phenolic compounds) were associated with tolerance mechanisms. Altogether, these results expand our knowledge about crops metabolic responses to high temperature and water deficit. These findings can be further explored in breeding programs to improve crop resilience to climate change and meet food security.
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22

Singh, Daljit. "Phenomics enabled genetic dissection of complex traits in wheat breeding." Diss., 2018. http://hdl.handle.net/2097/39324.

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Doctor of Philosophy
Genetics Interdepartmental Program
Jesse A. Poland
A central question in modern biology is to understand the genotype-to-phenotype (G2P) link, that is, how the genetics of an organism results in specific characteristics. However, prediction of phenotypes from genotypes is a difficult problem due to the complex nature of genomes, the environment, and their interactions. While the recent advancements in genome sequencing technologies have provided almost unlimited access to high-density genetic markers, large-scale rapid and accurate phenotyping of complex plant traits remains a major bottleneck. Here, we demonstrate field-based complex trait assessment approaches using a commercially available light-weight Unmanned Aerial Systems (UAS). By deploying novel data acquisition and processing pipelines, we quantified lodging, ground cover, and crop growth rate of 1745 advanced spring wheat lines at multiple time-points over the course of three field seasons at three field sites in South Asia. High correlations of digital measures to visual estimates and superior broad-sense heritability demonstrate these approaches are amenable for reproducible assessment of complex plant traits in large breeding nurseries. Using these validated high-throughput measurements, we applied genome-wide association and prediction models to assess the underlying genetic architecture and genetic control. Our results suggest a diffuse genetic architecture for lodging and ground cover in wheat, but heritable genetic variation for prediction and selection in breeding programs. The logistic regression-derived parameters of dynamic plant height exhibited strong physiological linkages with several developmental and agronomic traits, suggesting the potential targets of selection and the associated tradeoffs. Taken together, our highly reproducible approaches provide a proof-of-concept application of UAS-based phenomics that is scalable to tens-of-thousands of plots in breeding and genetic studies as will be needed to understand the G2P and increase the rate of gain for complex traits in crop breeding.
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