Made available in DSpace on 2017-07-10T17:36:52Z (GMT). No. of bitstreams: 1 2012_Diss_Joao_Ricardo_Pompermaier_Ramella.pdf: 1265373 bytes, checksum: d030ec8cc5626a02dbb5f4a6cc94fed3 (MD5) Previous issue date: 2012-04-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In the constant quest for sustainability of agriculture production systems, many studies are conducted with the objective of seeking alternatives to the problems generated by the use indiscriminate production systems. To present work aimed to study the effect on grain yield and forage in dual-purpose wheat cv BRS Tarumã under different managements related to nitrogen and number of cuts. The experiment was conducted in two trials during the period March 2011 to January 2012 red Eutrophyc Latossol area located at the experimental farm of Prof Dr. Antônio Carlos dos Santos Pessoa, city of Marechal Cândido Rondon - PR. The trial was conducted in a randomized block design with 12 treatments obtained by combinations of the numbers of cuts and increasing doses of nitrogen in four replications. We studied the yield and yield components, as well as forage productivity and its chemical composition, noting that for all variables significant interaction of doses of nitrogen and the number of cuts. The grain yield and yield components were responsive to the levels of nitrogen topdressing, as well as forage production and quality / Na constante busca pela sustentabilidade dos sistemas produtivos agropecuários, diversas pesquisas são realizadas com o objetivo de buscar alternativas aos problemas gerados pelo uso indiscriminado dos sistemas de produção. O presente trabalho teve como objetivo estudar os efeitos na produtividade de grãos e forragem em trigo de duplo propósito cv. BRS Tarumã sob diferentes manejos de cortes e adubação nitrogenada. O experimento foi conduzido durante o período de março de 2011 à janeiro de 2012 em área de Latossolo Vermelho Eutrófico localizada na fazenda experimental Prof. Dr. Antônio Carlos dos Santos Pessoa, cidade de Marechal Cândido Rondon PR. O ensaio foi conduzido sob delineamento de blocos ao acaso com 12 tratamentos obtidos pelas combinações do números de cortes e doses crescentes de nitrogênio em cobertura em quatro repetições. Foram estudadas a produtividade de grãos e seus componentes de rendimento, assim como a produtividade de forragem e sua composição bromatológica, observando que para todas as variáveis houve efeito da interação das doses de nitrogênio em cobertura e do número de cortes. A produtividade de grãos e seus componentes de rendimento foram responsivos aos níveis de adubação nitrogenada em cobertura, assim como a produção de forragem e sua qualidade

La compréhension des mécanismes régissant la recombinaison méiotique chez le blé tendre (Triticum aestivum L.) devient essentielle puisqu’elle est le levier principal utilisé par les sélectionneurs pour le brassage génétique et obtenir de nouvelles variétés élites comportant des introgressions de régions d’intérêt provenant de ressources génétiques exotiques. A cette fin, l’utilisation chez le blé tendre d’une nouvelle biotechnologie de ciblage de la recombinaison méiotique développée chez la levure par la société Meiogenix semble être prometteuse. Cette biotechnologie, nommée SpiX, fait intervenir un domaine protéique de liaison à l’ADN couplé à la protéine SPO11 responsable des cassures double-brins de l’ADN, initiatrices de la recombinaison méiotique ou crossovers (CO). Le développement d’une nouvelle technique de conservation des embryons immatures a permis d’améliorer les conditions de transformation par biolistique du blé tendre pour l’application de la technologie SpiX. L’exploitation de la séquence du génome du blé a permis d’isoler les gènes codant pour les protéines SPO11 du blé tendre. La complémentation hétérologue inédite de mutants pour les protéines SPO11 d’Arabidopsis thaliana avec les orthologues ainsi découverts chez le blé tendre montre leur grande conservation de séquence et de fonction au sein des plantes et leur potentielle fonctionnalité pour la biotechnologie SpiX. Enfin le test de différents domaines de liaison à l’ADN et de différentes cibles le long du chromosome 3B de blé tendre montre que la biotechnologie SpiX requiert des ajustements en fonction de l’espèce chez laquelle celle-ci doit fonctionner. Ces résultats sont ainsi l’opportunité de lever un premier voile sur le ciblage de la recombinaison méiotique chez une espèce de grande culture et de mieux comprendre les mécanismes de détermination des sites de cassures double-brins initiatrices de la recombinaison méiotique chez le blé tendre. / Understanding the mechanisms governing meiotic recombination in bread wheat (Triticum aestivum L.) is essential since it is the main tool used by breeders for genetic admixing and obtaining new elite varieties with introgression of regions of interest from exotic genetic resources. To this end, the use in bread wheat of a new biotechnology targeting meiotic recombination developed in yeast by Meiogenix seems to be promising. This biotechnology, named SpiX, involves a DNA-binding domain fused to the SPO11 protein responsible for DNA double-strand breaks, initiating meiotic recombination or crossovers (CO). The development of a new conservation protocol for wheat immature embryos has improved the conditions for bread wheat transformation through biolistic, and thus for the application of SpiX technology. The exploitation of the wheat genome sequence made it possible to isolate the bread wheat genes for SPO11 proteins. A novel heterologous complementation of Arabidopsis thaliana mutants for SPO11s with the bread wheat orthologous freshly discovered shows their great conservation of sequence and function within plants and their potential functionality for SpiX biotechnology. Finally, the testing of different DNA-binding domains and different targets along bread wheat 3B chromosome shows that SpiX biotechnology requires adjustments depending on the species in which it has to function. These results are the opportunity to uncover the targeting of meiotic recombination in a widely cultivated crop species and to understand the mechanisms determining sites for double-strand breaks prior to meiotic recombination in wheat.

Le blé tendre, Triticum aestivum, représente une grande ressource dans l’alimentation humaine mais également dans l’industrie. En conséquence, la taille finale du grain de blé constitue une cible privilégiée des programmes de sélections variétales. Pour ces raisons, comprendre les mécanismes moléculaires qui contrôlent le développement du grain, en particulier lors des phases précoces de la mise en place des structures cellulaires et leur remplissage par des réserves, constitue un enjeu majeur. Le développement du grain de blé est un processus complexe qui nécessite l’intervention séquentielle ou combinée d’un très grand nombre de gènes et de voies métaboliques. Parmi ces voies, le métabolisme carboné (en particulier celui du saccharose), les voies de signalisation par les hormones et la voie Ubiquitine / Protéasome 26S (UPS) semblent jouer un rôle déterminant dans la taille finale et donc le rendement en grain chez les céréales. Pour étudier le développement du grain de blé tendre, des plantes de la variété Récital ont été cultivées en serre dans des conditions optimales sans contraintes. Les grains ont été récoltés à onze stades de développement après floraison, allant de 40°CJ (soit deux jours après floraison) à 500°CJ (soit 25 jours après floraison). Les ARN totaux ont été extraits à partir de ces grains et utilisés pour analyser l’expression des gènes par une approche transcriptomique, soit en utilisant une lame « dédiée », soit en utilisant une lame Nimblegen comprenant 39 179 gènes. Une analyse différentielle utilisant le test LIMMA a permis d’identifier 9284 gènes différentiellement exprimés. L’analyse globale de ces gènes a montré que des modifications transcriptionnelles majeures ont lieu entre les stades 80 et 120 °CJ ainsi qu’entre 220 et 240°CJ. La répartition de ces 9284 en 10 clusters, en fonction de leurs profils d’expression, permet d’identifier les gènes activés en début de la phase de division cellulaire chez le grain, ceux activés pendant la phase de remplissage et ceux présentant un profil dit en « cloche ». Parmi les gènes différentiellement exprimés, nous nous sommes intéressés à ceux qui codent pour des E3 ligases impliquées dans la voie UPS et aux gènes relatifs à 7 hormones végétales (auxine, acide abscissique, acide jasmonique, brassinostéroïdes, cytokinines, gibbérellines et éthylène). Nous avons alors identifié 173 gènes codant pour des E3 ligases (dont certaines sont également des récepteurs hormonaux) et 126 gènes impliqués dans les voies hormonales. Un modèle global décrivant la chronologie d’intervention de ces gènes a été proposé. La majorité des gènes E3 de type SCF (SKP1-Cullin-Fbox), APC/C, Cul3-BTB et Ubox interviendrait dans les phases précoces du développement du grain de blé. Parallèlement, la majorité des gènes relatifs à l’auxine, à l’acide jasmonique et aux brassinostéroïdes interviendrait lors des phases de divisions cellulaires alors que les gènes relatifs à l’éthylène et à l’acide abscissique interviendraient dans les phases de remplissage. Par ailleurs, une méta-analyse a été réalisée et a permis d’identifier 26 gènes candidats codants pour des E3 ligases ainsi que de 12 gènes candidats impliqués dans les voies hormonales qui seraient préférentiellement exprimés dans l’albumen, un tissu du grain à haute valeur agro-économique. Le modèle proposé et l’identification de ces gènes candidats établissent un cadre pour de futures études visant à comprendre les mécanismes moléculaires contrôlant le développement du grain de blé. / Wheat grain is an important source of food, feed, and industrial raw materials, but current production levels cannot meet world needs. Elucidation of the molecular mechanisms underlying wheat grain development will contribute valuable information to improving wheat cultivation. One of the most important mechanisms implicated in plant developmental processes is the Ubiquitin-Proteasome System (UPS). Among several implications of the UPS, it has become clear that it plays an essential role in hormone signaling. In particular E3 ubiquitin ligases, from the UPS, have been demonstrated to play critical roles in hormone perception and signal transduction. During these work, wheat cv. Recital were grown in optimum growth conditions. By comparing eleven consecutive time-points from 40°CJ (2 days after anthesis) to 500°CJ (around 25 days after anthesis), 9284 differentially expressed genes were identified during this study. A comparison of these genes in terms of time revealed dynamic transcript accumulation profiles with major re-programming events that occurred during the time intervals of 80-120°Cdays and 220-240°Cdays. The gene expression comparison allows observing genes potentially involved in cell division or grain filling stage. An emphasis was made on the E3 ligases and hormone-related genes (Abscisic acid, Auxin, Brassinosteroid, Cytokinine, Gibberellic acid, Ethylene and Jasmonic acid). 173 E3 ligase coding genes and 126 hormone–related genes were found to be differentially expressed during the cell division and grain filling stages, with a different expression profile for each family. A model describing the timing of the involvement of these genes is proposed to provide a framework for the design of future experiments and for the identification of genes and pathways for further characterization. A majority of the E3 SCF (SKP1-Cullin-F-box), APC/C, Cul3-BTB and Ubox are found expressed in early wheat developmental stages (cell division stage). A majority of auxin, jasmonic acid and brassinostéroïde related genes were found to be up-regulated in early wheat developmental stages while ethylene and abscisic acid related genes were found to be activated during grain filling stage. The differential expression of genes involved in E3 ligase pathways and plant hormone signalling suggested that phytohormones and UPS crosstalk might play a critical role in the wheat grain developmental process. A meta-analysis of these genes led to the identification of 26 E3 ligase candidate genes and 12 hormones-related candidate genes that are preferentially expressed in the endosperm. The functional model that we proposed and the identification of candidate genes should help to better understand wheat grain development.

Fundação de Amparo a Pesquisa no Estado do Rio Grande do Sul / The intercropping between two species of agronomic interest adds more complex research and guidelines, as there is growth, development and resource sharing. When not planned correctly the consortium may bring harm. Thus, silvopastoral systems, characterized by cultivating a consortium of tree species and forage species, can cause production losses due to natural shading tax species in the understory. Seeking to create new alternatives of tree species to compose silvopastoral systems, the objective of this study was to analyze the dual purpose wheat cultivation in different silvopastoral systems. Tree species that comprised the SSP's were red mimosa (Parapiptadenia rigida) canafístula (Peltophorum dubium), eucalyptus (Eucalyptus grandis) and guapuruvu (Schizolobium parahyba), in addition to growing in full sun environment. The dual purpose wheat genotype used was BRS Tarumã (Triticum aestivum). It was observed the change of weather elements, solar radiation, air temperature and relative humidity inside the shaded environments. The reduction in light intensity affected the growth and development of wheat and stimulated culture change morphoanatomic structures to survive this stress. It was observed under shading conditions that wheat plants have increased the number and volume of intercellular spaces, reduced substomatic and cutinização cells. It found an increase in the thickness of paper and reduction in stomatal density. Plants grown in shaded environments had lower values of LAI, staying for shorter periods of time. As a result increase was observed in the same conversion efficiency, however, the end yield of dry matter and grain yield is adversely affected. The leaf emission was affected by the variation in brightness between the environments. Treatments with high transmissivity ensured higher leaf emission in wheat plants. Most phyllochron was observed in shaded environments while growing full sun got much smaller phyllochron values. The variation in the intensity of solar radiation impose changes both morphoanatomic as the growth and development of wheat plants. It is essential for the culture to develop changes in a plant structure in order to acclimatise to the environment with radiation deficit. / O cultivo consorciado entre duas espécies de interesse agronômico agrega pesquisas e direcionamentos mais complexos, pois há o crescimento, desenvolvimento e compartilhamento de recursos. Quando não planejado de forma correta o consórcio pode trazer prejuízos. Assim, os sistemas silvipastoris, caracterizados pelo cultivo em consórcio de espécies arbóreas e espécies forrageiras, podem causar perdas de produção devido ao sombreamento natural imposto sobre a espécie em sub-bosque. Visando à criação de novas alternativas de espécies arbóreas para compor sistemas silvipastoris, o objetivo do trabalho foi analisar o cultivo do trigo duplo propósito em diferentes sistemas silvipastoris. As espécies arbóreas que compuseram os SSP s foram angico vermelho (Parapiptadenia rigida), canafístula (Peltophorum dubium), eucalipto (Eucalyptus grandis) e guapuruvu (Schizolobium parahyba), além do cultivo em ambiente pleno sol. O genótipo de trigo duplo propósito utilizado foi o BRS Tarumã (Triticum aestivum). Foi observado a alteração dos elementos meteorológicos, radiação solar, temperatura do ar e umidade relativa do ar no interior dos ambientes sombreados. A redução na intensidade de luz afetou o crescimento e desenvolvimento do trigo e estimulou a cultura a modificar estruturas morfoanatômicas para sobreviver a esse estresse. Foi observado sob condições de sombreamento, que plantas de trigo aumentaram o número e o volume de espaços intercelulares, câmaras subestomáticas e reduziram a cutinização de células. Constatou-se incremento na espessura de folha e redução na densidade estomática. Plantas cultivadas em ambientes sombreadas obtiveram menores valores de IAF, permanecendo por menor período de tempo. Como consequência foi observado aumento na eficiência de conversão das mesmas, no entanto, a produção final de matéria seca e grãos foi afetada negativamente. A emissão foliar foi afetada pela variação na luminosidade entre os ambientes. Tratamentos com altas transmissividades asseguraram maior emissão foliar em plantas de trigo. Maior filocrono foi observado em ambientes sombreados, enquanto o cultivo pleno sol obteve valores de filocrono bem menores. A variação na intensidade da radiação solar impõe mudanças tanto morfoanatômicas quanto no crescimento e desenvolvimento de plantas de trigo. É fundamental para essa cultura desenvolver mudanças na sua estrutura vegetal com o intuito de aclimatar-se ao ambiente com déficit de radiação.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Wheat (Triticum aestivum) is the second largest world production of grains, with great importance in food and feed. It needs more technologies that provide productivity increases at low cost. A newly available technology for the wheat crop is the seed inoculation with growth promoting bacteria and atmospheric nitrogen fixing. The study was divided into two chapters, the first to evaluate the influence of inoculation and its interaction with the chemical seed treatment on germination, vigor and initial growth of wheat cultivars. To this end, we conducted an experiment in Didactic Laboratory and Seeds Research in UFSM in 2013. The second chapter aimed to verify the contribution of Azospirillum brasilense bacteria for biological nitrogen fixation on yield components in the culture wheat in different cultivars, management of nitrogen fertilization, local, sowing dates and years of cultivation. For this, experiments were conducted in the years 2013 and 2014 in Santa Maria and Cruz Alta cities. Inoculation promoted the increase of the dry mass of wheat seedlings in cultivars FUNDACEP Bravo, TBIO Itaipu and BRS 331, seven days after sowing, not affecting the other variables. The chemical treatment of seeds with fungicide triadimenol reduced germination, emergence and early growth of wheat seedlings. Inoculation had a positive response to productivity and hectoliter mass (HM) in some cultivars, with a maximum increase of 21% productivity in genotype TEC 07-244, the second sowing date 2014, in Cruz Alta. For HM, there were significant increases, especially during 1, 2013 in Santa Maria, where the average was 75,6 and 77,2 kg hL-1, for non-inoculated and inoculated, respectively. The nitrogen was important to improve the yield of wheat components, providing great increases in productivity, with better increments per kg of N applied at the rate of 50 kg N ha-1. / O trigo (Triticum aestivum) representa a segunda maior produção de grãos do mundo, com grande importância na alimentação humana e animal. Necessita-se de mais tecnologias que proporcionem aumentos de produtividades com baixo custo. Uma tecnologia recentemente disponível para a cultura do trigo é a inoculação de sementes com bactérias promotoras de crescimento e fixadoras de nitrogênio atmosférico. O trabalho foi dividido em dois capítulos, sendo o primeiro com objetivo de avaliar a influência da inoculação e sua interação com o tratamento químico de sementes na germinação, vigor e crescimento inicial de cultivares de trigo. Para tal, conduziu-se um experimento no Laboratório Didático e de Pesquisa em Sementes da UFSM no ano de 2013. O segundo capítulo teve por objetivo verificar a contribuição da bactéria Azospirillum brasilense para a fixação biológica de nitrogênio sobre os componentes de rendimento na cultura do trigo, em diferentes cultivares, manejos da adubação nitrogenada, locais, épocas de semeadura e anos de cultivo. Para isto, conduziram-se experimentos nos anos de 2013 e 2014, nos municípios de Santa Maria e Cruz Alta. A inoculação promoveu o aumento da massa seca de plântulas de trigo nas cultivares FUNDACEP Bravo, TBIO Itaipu e BRS 331, aos sete dias após a semeadura, não afetando as demais variáveis estudadas. O tratamento químico de sementes com o fungicida triadimenol reduziu a germinação, emergência e o crescimento inicial das plântulas de trigo. A inoculação apresentou resposta positiva para a produtividade e massa do hectolitro (MH) em algumas cultivares, com incremento máximo de 21% de produtividade na cultivar TEC 07-244, na segunda época de semeadura de 2014, em Cruz Alta. Para a MH, houve aumentos significativos, principalmente na época 1 de 2013 em Santa Maria, onde a média foi 75,6 e 77,2 kg hL-1, para as não inoculadas e inoculadas, respectivamente. A adubação nitrogenada foi importante para a melhoria nos componentes do rendimento do trigo, proporcionando grandes incrementos na produtividade, com melhores incrementos por kg de N aplicado na dose de 50 kg de N ha-1.

Made available in DSpace on 2015-03-26T13:40:05Z (GMT). No. of bitstreams: 1 texto completo.pdf: 841636 bytes, checksum: e76fa6ba8697bd0a60aa4b219d3b0456 (MD5) Previous issue date: 2007-03-02 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objective of this work was to study the effects of nitrogen fertilization and growth retardants on wheat (Triticum aestivum L.) crop. The study was conducted at the Experimental Station Prof. Diogo Alves de Mello, Federal University of Viçosa, Viçosa-MG (20º45 ' S; 42º51 ' W; 650-m altitude), in 2005 and 2006. Three experiments were carried out in a randomized block design with four repetitions. In the first experiment, two wheat cultivars (BRS 210 and Pioneiro) were fertilized by two methods of N application (total dose applied at seed sowing or 20 kg ha-1 at sowing and the remaining as topdressing in the beginning of tillering), and five N doses (40, 60, 80, 100, 120 kg ha-1) in a 2X2X5 factorial design. The results showed that the cultivar Pioneiro had higher productive potential than cultivar BRS 210, however with lower lodging resistance; splitting nitrogen fertilization increased lodging and brought no benefit to grain yield; grain yield response to N doses was quadratic, reaching maximum at 96.8 kg ha-1, and produced linear increase in lodging of cultivar Pioneiro. The second experiment, with the cultivar Pioneiro, had factors arranged in factorial and hierarchical design with a control treatment. The treatments consisted of three growth retardants (chlormequat, trinexapac-ethyl and paclobutrazol) combined in three doses (500, 1000 and 1500 g ha-1 of chlormequat; 62.5, 125 and 187.5 g ha-1 of trinexapac-ethyl and 40, 80 and 120 g ha-1 of paclobutrazol) with two application times (Time 1 = growth stage 6 or Time 2 = growth stage 8 of Feeks and Large scale), and a control treatment lacking retardant application. There was no occurrence of lodging in any of the studied treatments. It was concluded that trinexapac-ethyl and chlormequat were efficient in reducing wheat plant height; paclobutrazol was not efficient in reducing plant height; chlormequat and paclobutrazol effect on plant height was independent of application time; trinexapac-ethyl applied at growth stage 8 produced more marked effects than when applied at the stage 6 of the referred scale; the increase in retardant doses produced lower plant heights; chlormequat doses and paclobutrazol had no effect on grain yield; the largest trinexapac-ethyl doses reduced yield. The third experiment was arranged in a 5X4 factorial design, consisting of a combination of five nitrogen doses (30, 60, 90, 120, 150 kg ha-1) with four doses of the growth retardant trinexapac-ethyl (0, 62.5, 125, 187.5 g ha-1). Lodging and height of plants increased linearly with increase of nitrogen doses and with reduction of trinexapac-ethyl doses. Grain yield decreased with the increase of trinexapac-ethyl doses in the treatments with 30 and 60 kg ha-1 N, gave quadratic response in the treatments with 90 and 120 kg ha-1 N and had linear increase with 150 kg ha-1 N. Increasing N doses produced quadratic responses of grain yield with 0, 62.5, and 125g ha-1 of trinexapac-ethyl and linear increase with 187.5 g ha-. The results led to the conclusion that the application of 0, 62.5, 125 and 187.5 g ha-1 of 1 trinexapac-ethyl allows the use of 83.46; 92.21; 100.95 and 150 kg ha-1 of N, respectively, and that 60 kg ha-1 N without trinexapac-ethyl produces the highest grain yield. / O objetivo desta pesquisa foi estudar os efeitos da adubação nitrogenada e de redutores de crescimento na cultura do trigo (Triticum aestivum L.). O estudo foi conduzido na Estação Experimental Prof. Diogo Alves de Mello, da Universidade Federal de Viçosa, Viçosa-MG (20º45 S e 42º51 W e altitude de 650 metros), nos anos de 2005 e 2006. Foram realizados três experimentos, no delineamento de blocos casualizados com quatro repetições. No primeiro, duas cultivares de trigo (BRS 210 e Pioneiro) foram submetidas a duas formas de aplicação de N (dose total aplicada por ocasião da semeadura ou 20 kg ha-1 na semeadura mais o restante da dose em cobertura, no início do perfilhamento) e cinco doses de N (40, 60, 80, 100, 120 kg ha-1), constituindo um fatorial 2X2X5. Conclui-se que a cultivar Pioneiro apresenta maior potencial produtivo que a cultivar BRS 210, porém apresenta menor resistência ao acamamento; o parcelamento da adubação nitrogenada proporciona maior acamamento e não traz benefícios à produtividade dos grãos; as doses de N promovem resposta quadrática da produtividade dos grãos, com ponto de máxima estimado na dose de 96,8 kg ha-1 e, aumento linear do acamamento de plantas da cultivar Pioneiro. O segundo experimento, conduzido com a cultivar Pioneiro, foi montado com fatores em esquema fatorial e hierárquico com uma testemunha. Os tratamentos foram três redutores de crescimento (clormequat, trinexapac-etil e paclobutrazol) combinados com três doses (500, 1000 e 1500 g ha-1 de clormequat; 62,5, 125 e 187,5 g ha-1 de trinexapac-etil e 40, 80 e 120 g ha-1 de paclobutrazol) e duas épocas de aplicação (Época 1= estádio 6 ou Época 2= estádio 8 da escala Feeks e Large), mais um tratamento testemunha que não recebeu aplicação de redutor. Não houve acamamento de plantas em nenhum dos tratamentos estudados. Conclui-se que o trinexapac-etil e o clormequat são eficientes em reduzir a estatura das plantas de trigo; o paclobutrazol não é eficiente em reduzir a estatura das plantas; a ação dos redutores clormequat e paclobutrazol sobre a altura de plantas independe da época de aplicação; o trinexapac-etil aplicado na época em que as plantas encontram-se no estádio 8 promove efeitos mais acentuados, do que quando aplicado no estádio 6 da referida escala; o aumento das doses dos redutores promove menor estatura das plantas; as doses de clormequat e paclobutrazol não afetam a produtividade dos grãos; as maiores doses de trinexapac-etil promovem redução na produtividade. O terceiro experimento foi conduzido seguindo um fatorial 5X4, constituído pela combinação de cinco doses de nitrogênio (30, 60, 90, 120, 150 kg ha-1) com quatro doses do redutor de crescimento trinexapac-etil (0, 62,5, 125, 187,5 g ha-1). O acamamento e a altura das plantas aumentaram linearmente com o incremento das doses de nitrogênio e com redução das doses de trinexapac-etil. A produtividade dos grãos decresceu com o aumento das doses de trinexapac-etil, nos tratamentos com 30 e 60 kg ha-1 de N, respondeu de forma quadrática nos tratamentos com 90 e 120 kg ha-1 de N e aumentou de forma linear na dose de 150 kg ha-1 de N. O aumento das doses de N promoveu respostas quadráticas da produtividade dos grãos, nas doses de 0; 62,5, 125g ha-1 de trinexapac-til e aumento linear na dose de 187,5 g ha-1 do redutor. Conclui-se que a aplicação de 0; 62,5; 125 e 187,5 g ha-1 de trinexapac-etil permite utilizar as doses de 83,46; 92,21; 100,95 e 150 kg ha-1 de N, respectivamente, e que a dose de 60 kg ha-1 de N sem aplicação de trinexapac-etil promove a maior produtividade dos grãos.

Frente ao aumento populacional e consequente incremento na demanda por alimentos, é importante estabelecer um melhor aproveitamento da área de cultivo, objetivando a colheita de produtos agrícolas em maior quantidade e de melhor qualidade. O aumento da concentração de micronutrientes nos produtos colhidos, especialmente de zinco é um desafio crescente para a agricultura, com possibilidade de trazer benefícios à saúde humana e à produtividade da cultura. Nesse sentido, a aplicação foliar de zinco realizada periodicamente, à partir da antese floral, é uma técnica capaz de incrementar o teor do micronutriente nas sementes e biofortificar os grãos de feijão e trigo, causando melhoria de aspectos agronômicos (crescimento vegetativo e produtividade da cultura) de plantas provenientes dessas sementes, além de resultar proveitos para a saúde humana daqueles que se alimentam de produtos biofortificados, e ainda com potencial para produzir grãos e sementes como produtos de maior valor comercial no mercado, valendo-se de inovação tecnológica. Porém, atualmente pouco se conhece sobre os diversos aspectos desta técnica. Assim sendo, objetivou-se: (i) elucidar o efeito da aplicação foliar de zinco, à partir da antese floral, como método para incrementar o teor do micronutriente nos grãos de feijão (Phaseolus vulgaris L.) e de trigo (Triticum aestivum L.), em substrato com teor adequado do micronutriente (ii) utilização de diferentes fontes de zinco aplicadas via foliar visando estabelecer a melhor fonte para o aumento do teor do micronutriente no grão de feijoeiro e (iii) determinação das doses de zinco mais adequadas a serem aplicadas através de pulverização foliar visando o aumento do teor do nutriente no grão de plantas de feijão e de trigo. Com base nos resultados obtidos, concluiu-se que (i) a aplicação foliar de zinco realizada periodicamente, à partir da antese floral é capaz de aumentar o teor do micronutriente em grãos de feijão e de trigo; (ii) a fonte mais viável para o enriquecimento de grãos de feijão é o sulfato de zinco; (iii) e todas as doses testadas (125, 250, 375 e 500 g Zn ha-1) aplicadas via foliar na forma de sulfato de zinco foram efetivas para o enriquecimento de grãos de feijão e de trigo, em relação ao controle (0 g Zn ha-1). / In view of the population increase and consequent growth of food demand, it is important to establish a better utilization of the cultivation area, aiming the harvest of agricultural products in greater quantity and of better quality. The increased concentration of micronutrients in products harvested, especially zinc, is a growing challenge for agriculture, with potential to bring benefits to human health and crop productivity. In this matter, the foliar zinc application performed periodically starting at floral anthesis is a technique capable of increasing the micronutrient content in the seeds and biofortifying grains of common bean and wheat, causing agronomic aspects improvement (vegetative growth and crop productivity) of plants derived from these seeds, in addition to bringing benefits to human health of those who feed on biofortified products, and still with potential to produce grains and seeds as products of greater commercial value in the market, being a technological innovation. However, currently little is known about the aspects that circumvent this technique. The objective of this study was: (i) elucidate the effect of foliar application of zinc, starting at floral anthesis, as a method to increase the micronutrient content of common bean (Phaseolus vulgaris L.) and wheat (Triticum aestivum L.) (ii) the use of different sources of zinc applied in a foliar way, in order to establish the best source for increasing the micronutrient content in common bean grains, and (iii) the determination of the most suitable zinc doses, applied by foliar spraying to increase the nutrient content of common bean and wheat plants. Based on the results obtained, it was concluded that (i) the periodic application of zinc foliar application starting at floral anthesis is capable of increasing the micronutrient content in common bean and wheat grains; (ii) the most viable source for the enrichment of bean grains is zinc sulphate; (iii) and all the doses tested (125, 250, 375 and 500 g Zn ha-1) applied via foliar in the form of zinc sulfate were effective for the enrichment of common bean and wheat grains, in relation to the control (0g Zn ha-1).

A aplicação de micronutrientes nas sementes pode constituir alternativa interessante para a disponibilização destes elementos às plantas, reduzindo perdas e disponibilizando-os no início do desenvolvimento das mesmas, favorecendo sua utilização. O nutripriming da semente é uma técnica em que há hidratação das sementes com solução aquosa de nutrientes, associando os benefícios do priming com a disponibilização de elementos essenciais à nutrição vegetal. Assim, foi avaliada a adequação do priming para as sementes de trigo, do nutripriming com a aplicação do cobre e do manganês e a interferência desses procedimentos na qualidade da semente e no desenvolvimento da plântula; foram utilizados os cultivares Quartzo e Supera, avaliados em cinco épocas: inicial e aos 45, 90, 135 e 180 dias. Para a avaliação das sementes foram determinados o teor de água, a germinação (total e primeira contagem), a emergência da plântula (total e índice de velocidade), os comprimentos da plântula (manualmente e com o software SVIS®), a condutividade elétrica e os índices de vigor e uniformidade de plântulas O experimento foi conduzido em esquema fatorial 7 x 2 (controle e doses de micronutrientes x sementes sem priming e com nutripriming), em delineamento experimental inteiramente casualizado. Independentemente do cultivar, o nutripriming em sementes de trigo, utilizando doses superiores a 100 mg de Cu/kg de semente, afeta negativamente o desenvolvimento da plântula reduzindo o crescimento das raízes. A aplicação na semente de trigo, doses 10 e 33 mg de Cu/kg de semente, sem priming ou utilizando nutripriming, não causa redução da qualidade da semente e não compromete o desenvolvimento da plântula. A utilização do manganês, independentemente do cultivar e da forma de aplicação, não interfere negativamente na qualidade da semente e no desenvolvimento da plântula. / Micronutrient application through seeds may consist in an interesting alternative to provide these elements to plants, reducing losses and making them available at their initial growth stages, which may favor their utilization. Nutripriming is a technique that involves seed hydration in aqueous nutrient solution, which combines the priming benefits with the supply of essential elements for plant nutrition. Thus, this research evaluated the adequacy of priming for wheat seeds, the application of copper and manganese through nutripriming and the interference of these procedures on seed quality and seedling development. Wheat cultivars Quartzo and Supera were used; the evaluations were performed in five periods: initial (day 1), 45, 90, 135 and 180 days. Seeds were evaluated by water content, germination (total and first count), seedling emergence (total and speed index), seedlings length (manually and with SVIS® software), electrical conductivity and vigor and uniformity indices seedlings. The experiment was conducted in a completely randomized factorial design 7 x 2 (control and doses of micronutrients x non-primed and primed seeds). Regardless the cultivar, nutripriming of wheat seeds, at doses higher than 100 mg Cu / kg seed, negatively affects seedling development, reducing root length. The application of doses 10 and 33 mg Cu / kg seed, via seed dressing or nutripriming, does not affect seed quality and seedling development. The use of manganese, regardless the cultivar and application type, does not interfere on seed quality and seedling development.

Dans le but d’identifier des critères de sélection du blé (T. aestivum L.) destiné à la production de bioéthanol, les objectifs de cette thèse étaient (1) de mettre en évidence les caractéristiques physico-chimiques du grain associées aux rendements en glucose et éthanol, et (2), d’étudier par approche protéomique l’effet de variants génétiques affectant la quantité d’amylose sur le métabolisme des sucres et de l’amidon. L’analyse de trente variétés implantées dans un essai multilocal pluriannuel a mis en évidence l’importance du taux de protéines, de la dureté et de la distribution des granules d’amidon sur les rendements en glucose et éthanol. Dans une moindre mesure, la composition allélique des protéines de réserves et la viscosité des arabinoxylanes ont également un effet lors de l’étape de transformation de l’amidon en sucres fermentescibles. Huit lignées isogéniques waxy de trois variétés françaises ont été implantées dans un essai multilocal. Les lignées dépourvues d’amylose ont produit moins de glucose et d’éthanol que les variétés normales. Les analyses protéomiques des protéines de l’albumen (albumines, globulines et amphiphiles) ainsi que des protéines associées aux granules d’amidon des grains matures des lignées isogéniques de la variété Trémie ont mis en évidence : (1) une relation entre le volume spécifique des GBSS et la quantité d’amylose et (2) une modification de l’expression d’enzymes impliquées dans le métabolisme des sucres et de l’amidon (Susy, AGPase, fructose biphosphate aldolase) mais aussi de protéines de stress et de défense (serpines et HSP). Ces observations suggèrent un développement du grain incomplet pour la lignée dépourvue d’amylose. / To identify selection criteria for wheat (T. aestivum L.) used for bioethanol production, our objectives were (1) to identify the physicochemical grain characteristics associated with glucose and ethanol yields and (2) using a proteomic approach, to study the impact on sugar and starch metabolism of genetic variants that influence the quantity of amylose. The analysis of 30 wheat varieties grown in a 3-year multi-local field trial underlined the importance of protein content, grain hardness and starch granule size distribution for glucose and ethanol yields. A minor effect of the allelic composition of the storage proteins and of viscosity on the transformation of starch in fermentable sugars was also revealed. Eight waxy isogenic lines of three French varieties were grown in a multi-local field trial. The amylose-free lines produced less glucose and ethanol than normal varieties. Proteomic analyses of endosperm proteins (albumins, globulins and amphiphilic proteins) and of proteins associated with starch granules in mature grains of isogenic lines of the Tremie variety revealed : (1) a relation between the specific volume of the GBSS and amylose quantity and (2) a modification of the expression of enzymes involved in starch and sugar metabolism (Susy, AGPase, Fructose biphosphate aldolase) and also in stress and defence proteins (serpins and HSP). These observations suggest incomplete grain development in the line without amylose.

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