Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 6 uppsatser.

The Eastern Cape Province of South Africa has climatic conditions which differ from region to region. The groundnut (Arachis hypogaea L.) cultivars, as it is the case with other crops, do not always perform equally well in the varying conditions. Abiotic stresses such as drought, extreme temperatures, and high soil acidity restrict plant growth. Lack of studies on adaptability of commercial groundnut cultivars in the Eastern Cape necessitated this study. Abiotic and biotic factors are not the only limiting factors: calcium availability in the soil is also a limiting factor in groundnut production. The aim of the study was to identify best suited cultivars for climatic conditions of Mthatha and Lusikisiki regions of the Eastern Cape. Two similar field experiments were conducted in the two locations with different climatic conditions. The results showed significant differences (P<0.05) in genotypes with respect to seed yield in both locations. Kwarts produced higher seed yield of 1155 kg ha-1 in Mthatha, while the same genotype produced low seed yield of 630 kg ha-1 in Lusikisiki location. In Lusikisiki the highest seed yield was recorded in Anel (936 kg ha-1) which produced low yield of 692 kg ha-1 in Mthatha. The genotypes that performed well in Mthatha in 2010/11 season included Kwarts, Nyanda, ICGV-SM 95714 and Mwenje. These genotypes were further used to investigate their response to calcium supplementation at flowering stage under conditions of Mthatha in the 2011/12 season. The results were significantly different for calcium absorption (P<0.05). Nyanda, Kwarts and Mwenje responded positively to calcium application at flowering stage producing relatively high yield of 153, 150 and 110 kg ha-1, respectively. Oil content was significantly increased by calcium application at flowering in Nyanda with 27.28% compared to 20.7% without Ca.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.

Le développement de variétés performantes de blé dur (Triticum turgidum durum) doit prendre en compte la corrélation négative entre rendement et teneur en protéines (GPC). Une meilleure compréhension de ce phénomène nécessite une connaissance de l'élaboration des composantes de ces variables. Au cours de cette thèse nous nous sommes focalisés sur l'étude du déterminisme de paramètres foliaires pendant le remplissage du grain (morphologie, résorption d'azote/senescence) ainsi que leurs relations avec les caractéristiques post-récolte (rendement, GPC). La population d'étude est constituée de 282 lignées recombinantes issues d'un croisement demi-diallèle entre quatre lignées élites. Les données proviennent d'expérimentations menées en milieu contrôlé (3 expérimentations) et en plein champ (2 essais).En milieu contrôlé, plusieurs variables (teneur en azote, masse surfacique) ont été prédites par spectrométrie infrarouge à raison de mesures régulières au cours de la période d'intérêt. La résorption d'azote de la dernière feuille a été modélisée pour chaque génotype dont les paramètres ont été analysés. Un lien négatif fort a été établi entre la date d'initiation de la résorption (t0) en temps thermique post-floraison et sa durée et un lien positif entre cette date clé et le poids individuel des grains. A l'échelle de la parcelle, le suivi dynamique de la senescence par la mesure d'évolution d'un indice de végétation, le NDVI (Normalized Difference Vegetation Index) a montré une relation forte entre vitesse d'évolution de la senescence et son ordonnée à l'origine, suggérant que la fin de la senescence était un phénomène très contraint dans les conditions environnementales de plein champ.En absence de stress azoté, l'analyse des 4 géniteurs a montré que des combinaisons linéaires de paramètres foliaires permettaient d'expliquer environ 2/3 des variations de la production en grains d'un épi et de la GPC. En considérant l'ensemble de la population, les effets antagonistes d'une résorption tardive sur la production de grains et la teneur en protéines ont été établis. Une carence en azote appliquée post-floraison provoque une résorption précoce et longue, ce qui semble d'avantage affecter la GPC que le rendement. Une carence en azote appliqué pré-floraison réduit la quantité d'azote disponible dans les feuilles drapeau (et par conséquent leur potentiel photosynthétique) ainsi que le nombre de grains alors que les apports tardifs en azote réalisés dans ce traitement vont retarder la résorption donc augmenter le poids individuel des grains et la GPC. L'analyse génétique en modèle mixte a permis de prendre en compte un apparentement entre lignées, calculé grâce aux pedigrees ou aux marqueurs. Ces deux estimateurs de l'apparentement sont très fortement corrélés ; l'ordonnée à l'origine de la relation (0.3) pouvant être interprétée comme une mesure de l'identité par état de la population de base à partir de laquelle les géniteurs sont issus. Par conséquent, les variances additives issues d'un apparentement marqueurs sont systématiquement supérieures à celles d'un apparentement pedigree. Les valeurs d'héritabilité des variables étudiées caractérisant la morphologie de la feuille drapeau à floraison et des paramètres de résorption d'azote sont du même ordre de grandeur que celles du rendement d'un épi et de la teneur en protéines des grains.En conclusion, nous discutons des stratégies de sélection autour de la corrélation négative rendement/GPC en lien avec la résorption d'azote et la senescence, de l'intérêt de l'utilisation du modèle dit « animal » pour les analyses génétiques et la recherche de QTL. / Performing cultivar development of durum wheat (Triticum turgidum durum) have to take in consideration the negative correlation existing between yield and grain protein content (GPC). A best comprehension of this phenomenon needs the knowledge of these variables elaboration. During this thesis, we focused on the study of foliar parameters determinism during the grain filling (morphology, nitrogen resorption/senescence) and their relations with post-harvest parameters (yield, GPC). The population was formed of 282 recombinant lines coming from a half-diallel cross between 4 elite lines. Data are from experimentations on controlled environment (3 experimentations) and on field (2 experimentations).In controlled environment, various variables (nitrogen content, mass area) were predicted using near-infrared spectroscopy and performing regular measures during the period of interest. Nitrogen resorptions of the last leaf were modeled for each genotype and parameters were analyzed. A strong negative correlation was established between the resorption initiation date (t0) in thermal time post-flowering and its duration and a positive correlation was established between t0 and the grain individual weight. At the plot scale, the dynamic monitoring of senescence through measures of NDVI (Normalized Difference Vegetation Index) evolution showed a strong relation between the senescence evolution rate and its intercept, suggesting the senescence end was a very constraint phenomenon in field.Without nitrogen stress, the analysis of the 4 genitors indicated that linear combinations of foliar parameters could explain around 2/3 of one-spike grain production and GPC variations. Considering the entire population, the antagonist effects of a late resorption on grain production and on the GPC were established. A post-flowering nitrogen stress causes an early and long resorption which seems to affect more GPC than yield. A pre-flowering nitrogen stress reduces nitrogen quantity available in flag leaves (and consequently their photosynthetic potential) and the grain number whereas late nitrogen inputs of this environment delay resorption and raise grain individual weight and GPC.The genetic analysis in mixed model allowed taking into account relatedness among lines, calculated with pedigrees or markers. Those 2 relatedness estimators are strongly correlated; the regression intercept (0.3) can be interpreted as an identity-by-state measure of the base population from which genitors are derived. Consequently, additive variances from a marker-relatedness model are always superior to additive variances form a pedigree-relatedness model. Heritability values of the study variables (flag leaf morphology and nitrogen resorption parameters) have the same order of magnitude than those of one-spike yield and GPC.Field experimentations allowed highlighting the flag leaf weight as a contributor organ to yield and GPC. Nitrogen balance showed a link between post-flowering nitrogen fluxes and nitrogen available at flowering. Genotype-phenotype association's research was realized through a simple-marker analysis for all the experimentations and a Composite Interval Mapping analysis only for data obtained in greenhouses. A stable QTL was detected on the 3 controlled environments for t0. QTL comparison on controlled environment QTL and field QTL highlighted various area containing QTL on certain chromosomes: an area of foliar nitrogen content at flowering QTL on the 1A, an area of GPC QTL, Thousand Kernel Weight (TKW) QTL and grain number QTL on the 2A, an area of foliar morphology QTL on the 2B, an area of TKW QTL on the 3B and an area of senescence variables QTL on the 7B.In conclusion, we discuss about breeding strategies around the negative correlation yield/GPC in relations with nitrogen resorption and senescence and about the interest to use the “animal” model for genetic analysis and QTL research.

Orientador: Luiz Antonio Graciolli / Banca: Ana Maria Rodrigues Cassiolato / Banca: Eustáquio Souza Dias / Resumo: O presente trabalho teve por objetivo evidenciar os principais componentes químicos que influenciam o cultivo do cogumelo Pleurotus florida, bem como avaliar a composição química dos corpos de frutificação cultivados em diferentes resíduos agrícolas. Para tanto, foram utilizados seis resíduos agrícolas: palha de arroz (PA), palha de feijão (PF), palha de trigo (PT), palha de sorgo (PS), folha de bananeira (FB) e sabugo de milho (SM). Estes resíduos, coletados na Fazenda de Ensino, Pesquisa e Extensão da UNESP, Campus de Ilha Solteira, foram analisados quanto aos teores de macro (N, P, K, Ca, Mg) e micronutrientes (Fe, Mn e Zn), lignina, celulose, hemicelulose, cinzas e relação C/N. Foram avaliados: o tempo necessário para a colonização do substrato (corrida micelial), o início da formação de primórdios, o tempo total de cultivo, o número de cogumelos, a produção e a eficiência biológica utilizando a fórmula: EB = (peso fresco dos cogumelos/peso seco do substrato inicial) x 100. Além disso, os cogumelos foram avaliados quanto aos teores de macro (N, P, K, Ca e Mg) e micronutrientes (Fe, Mn e Zn) e o teor de proteínas. O substrato PF apresentou resultados semelhantes para produção (189,8 g/kg-1), EB (89,2%) e número de cogumelos (12) à PA, substrato utilizado tradicionalmente no cultivo de Pleurotus em escala comercial. Não foi possível atribuir apenas a um fator químico as altas produções e EB observadas em PA e PF e muito menos para a baixa produção em PS (77,8 g/kg-1) e SM (53,2 g/kg-1). No geral, substratos com conteúdo de N ao redor de 1,0%, relação C/N em torno de 45%, baixo teor lignina, alto conteúdo de cinzas e maiores teores de P, K e Ca foram os melhores para o cultivo de P. florida. Entre os macronutrientes analisados, P. florida apresentou maiores teores de K, seguido por P. O Ca e o Mg estiveram presentes em pequenas quantidades nos corpos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study aimed to show the main chemical components that influence the cultivation of the mushroom Pleurotus florida, and evaluate the chemical composition of fruiting bodies grown on different agricultural residues. For that, six agricultural residues were used: rice straw (RS), bean straw (BS), wheat straw (WS), sorghum straw (SS), banana leaf (BL) and cob of maize (CM). These wastes were collected at Teaching, Research and Extention Farm of UNESP, Campus of Ilha Solteira, analyzed for the levels of macro (N, P, K, Ca, and Mg) and micronutrients (Fe, Mn and Zn), lignin, cellulose, hemicellulose, ash and the C/N ratio. Was evaluated: spawn run time, earliness, the total time of cultivation and mushroom number, production and biological efficiency using the formula: EB = (fresh weight of mushrooms/dry weight of initial substrate) x 100. Moreover, the mushrooms were evaluated for levels of macro (N, P, K, Ca and Mg) and micronutrients (Fe, Mn and Zn) and protein content. The substrate BS showed similar results for yield (189,8 g/kg-1), EB (89,2%) and number of mushrooms (12) as RS substrate traditionally used for the cultivation of Pleurotus in commercial scale. Unable to allocate only the chemical factors and the high yields and EB observed in BS and RS, much less for the yield low in SS (77,8 g/kg-1) and CM (53,2 g/kg-1). In general, substrates with N content of around 1.0%, C/N ratio around 45%, low lignin content, high ash content, increased by higher levels of P, K, Ca were the best for the cultivation of P. florida. Among the macronutrients analyzed, P. florida with higher contents of K, followed by P. The Ca and Mg were present in small amounts in fruiting bodies. Among the micronutrients, Zn was present in high amount, followed by Fe and Mn. P. florida showed high ability to accumulate Zn. The mushrooms obtained in this work could not be considered a source of minerals... (Complete abstract click electronic access below) / Mestre

No description available.

CAPES; CNPQ / A Spirulina platensis é reconhecida como uma fonte não convencional de proteínas, em função da sua constituição favorável deste nutriente (46 a 63%), possuindo concentração superior a das carnes e da soja. Além disso, apresenta potencial como matéria-prima para a produção de bioetanol, podendo acumular entre 8,0 e 14,0% de carboidratos. A fim de abranger o conceito de Biorrefinarias Integradas, o objetivo deste trabalho consistiu em avaliar a extração conjunta de proteínas e carboidratos da biomassa de Spirulina platensis utilizando tratamento ultrassônico e agitação em meio alcalino, e a posterior produção e caracterização do concentrado proteico. Na primeira etapa do trabalho, aplicou-se uma estratégia sequencial de planejamento experimental (Planejamento Fatorial Fracionário (PFF) seguido de Delineamentos Compostos Centrais Rotacionais (DCCR)) para seleção e maximização das variáveis com influência significativa sobre o processo de extração. Com as condições de extração otimizadas, foi possível atingir recuperação final de 75,85% e de 41,54% de proteínas e carboidratos, respectivamente. Na segunda etapa do trabalho foi realizada a precipitação de proteínas, para a separação da fase líquida contendo os carboidratos e obtenção do concentrado proteico, o qual foi caracterizado quimicamente e de acordo com sua funcionalidade tecnológica. O concentrado proteico apresentou coloração verde azulada com 75,97% de proteínas (b.s.), concentrações apreciáveis de aminoácidos, sendo o que o triptofano apresentou o maior escore químico (1,71) e o aminoácido limitante foi a histidina; na análise da estrutura secundária das proteínas, as conformações mais abundantes foram β-folha e α-hélice. Na etapa de avaliação da funcionalidade tecnológica observou-se que o pH apresentou influência nas propriedades de capacidade de absorção de água, capacidade de formação e estabilidade de espuma e emulsão, e capacidade de formação de gel, o que pode ser justificado pela solubilidade desta proteína, que é mínima em pH 3,0 e máxima em 9,0. A concentração de concentrado proteico também interferiu no desempenho destas propriedades; melhores resultados foram obtidos em maiores níveis de concentração, exceto para a capacidade de absorção de água e de óleo. Desta forma foi possível determinar que as proteínas de Spirulina platensis podem contribuir na formulação de alimentos, possuindo características eficazes de formação de emulsões, espumas ou géis, bem como pode ser utilizada como fonte suplementar de proteínas. / Spirulina platensis is considered an unconventional source of protein, because its avorably constitution on this component (46 to 63%), which is higher than the meat and soy. Furthermore, it has potential as a feedstock for bioethanol production and can accumulate between 8.0 to 14.0% of carbohydrate. In order to cover the concept of Integrated Biorefineries, the aim of this study was to evaluate the combined extraction of proteins and carbohydrates from Spirulina platensis biomass using sonication and agitation, under alkaline conditions, and the subsequent production and characterization of protein concentrate. The first stage of this work consisted of applying a sequential strategy of experimental design (Fractional Factorial Design FFD) and Central Composite Rotatable Design (CCRD)) by selecting and maximizing variables with significant influence on the protein and carbohydrates extraction. With the extraction conditions established, a final yield of 75.85% and 41.54% from protein and carbohydrate, respectively, was reached. In the second step, the protein concentrate obtained by precipitation was submitted to chemical and echnological functionality analyzes. The protein concentrate showed blue-green color with 75.97% of proteins (dry weight), appreciable concentrations of amino acids, where tryptophan had the highest chemical score (1.71) and the limiting amino acid was histidine; the secondary structure of proteins showed that the most abundant conformations present were β-sheet and α-helice. At the step of echnological functionality evaluation it was observed that the pH influenced on the properties of water absorption capacity, foaming and emulsion capacity and stability, and gelation capacity; it can be justified by the solubility of this protein which is minimal at pH 3.0 and maximum at 9.0. The level of addition of protein concentrate also interfered on the performance of these properties; better results have been obtained at higher concentrations levels, except for water and oil absorption capacity. Thus, it was confirmed that the Spirulina platensis proteins may contribute in different ormulations of foods, having effective characteristics to form emulsions, foams or gels, and can be used as a supplemental source of protein.

CAPES; CNPQ / A Spirulina platensis é reconhecida como uma fonte não convencional de proteínas, em função da sua constituição favorável deste nutriente (46 a 63%), possuindo concentração superior a das carnes e da soja. Além disso, apresenta potencial como matéria-prima para a produção de bioetanol, podendo acumular entre 8,0 e 14,0% de carboidratos. A fim de abranger o conceito de Biorrefinarias Integradas, o objetivo deste trabalho consistiu em avaliar a extração conjunta de proteínas e carboidratos da biomassa de Spirulina platensis utilizando tratamento ultrassônico e agitação em meio alcalino, e a posterior produção e caracterização do concentrado proteico. Na primeira etapa do trabalho, aplicou-se uma estratégia sequencial de planejamento experimental (Planejamento Fatorial Fracionário (PFF) seguido de Delineamentos Compostos Centrais Rotacionais (DCCR)) para seleção e maximização das variáveis com influência significativa sobre o processo de extração. Com as condições de extração otimizadas, foi possível atingir recuperação final de 75,85% e de 41,54% de proteínas e carboidratos, respectivamente. Na segunda etapa do trabalho foi realizada a precipitação de proteínas, para a separação da fase líquida contendo os carboidratos e obtenção do concentrado proteico, o qual foi caracterizado quimicamente e de acordo com sua funcionalidade tecnológica. O concentrado proteico apresentou coloração verde azulada com 75,97% de proteínas (b.s.), concentrações apreciáveis de aminoácidos, sendo o que o triptofano apresentou o maior escore químico (1,71) e o aminoácido limitante foi a histidina; na análise da estrutura secundária das proteínas, as conformações mais abundantes foram β-folha e α-hélice. Na etapa de avaliação da funcionalidade tecnológica observou-se que o pH apresentou influência nas propriedades de capacidade de absorção de água, capacidade de formação e estabilidade de espuma e emulsão, e capacidade de formação de gel, o que pode ser justificado pela solubilidade desta proteína, que é mínima em pH 3,0 e máxima em 9,0. A concentração de concentrado proteico também interferiu no desempenho destas propriedades; melhores resultados foram obtidos em maiores níveis de concentração, exceto para a capacidade de absorção de água e de óleo. Desta forma foi possível determinar que as proteínas de Spirulina platensis podem contribuir na formulação de alimentos, possuindo características eficazes de formação de emulsões, espumas ou géis, bem como pode ser utilizada como fonte suplementar de proteínas. / Spirulina platensis is considered an unconventional source of protein, because its avorably constitution on this component (46 to 63%), which is higher than the meat and soy. Furthermore, it has potential as a feedstock for bioethanol production and can accumulate between 8.0 to 14.0% of carbohydrate. In order to cover the concept of Integrated Biorefineries, the aim of this study was to evaluate the combined extraction of proteins and carbohydrates from Spirulina platensis biomass using sonication and agitation, under alkaline conditions, and the subsequent production and characterization of protein concentrate. The first stage of this work consisted of applying a sequential strategy of experimental design (Fractional Factorial Design FFD) and Central Composite Rotatable Design (CCRD)) by selecting and maximizing variables with significant influence on the protein and carbohydrates extraction. With the extraction conditions established, a final yield of 75.85% and 41.54% from protein and carbohydrate, respectively, was reached. In the second step, the protein concentrate obtained by precipitation was submitted to chemical and echnological functionality analyzes. The protein concentrate showed blue-green color with 75.97% of proteins (dry weight), appreciable concentrations of amino acids, where tryptophan had the highest chemical score (1.71) and the limiting amino acid was histidine; the secondary structure of proteins showed that the most abundant conformations present were β-sheet and α-helice. At the step of echnological functionality evaluation it was observed that the pH influenced on the properties of water absorption capacity, foaming and emulsion capacity and stability, and gelation capacity; it can be justified by the solubility of this protein which is minimal at pH 3.0 and maximum at 9.0. The level of addition of protein concentrate also interfered on the performance of these properties; better results have been obtained at higher concentrations levels, except for water and oil absorption capacity. Thus, it was confirmed that the Spirulina platensis proteins may contribute in different ormulations of foods, having effective characteristics to form emulsions, foams or gels, and can be used as a supplemental source of protein.

Made available in DSpace on 2017-07-10T17:40:57Z (GMT). No. of bitstreams: 1 Tese_2012_Joao_Edson_Kaefer.pdf: 1393414 bytes, checksum: fdf2b5e5d88064ab53a8cf4b503d44bd (MD5) Previous issue date: 2012-06-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The canola term is an acronym for Canadian Oil Low Acid and was adopted as the standard to indicate low levels of erucic acid and glucosinolates. In general, tropical soils are poor in available nitrogen (N) because of the low stocks of organic matter, requiring the external supply of N to meet the demands of the culture. Among the main sources of N used in the culture of canola are nitrogen fertilizers urea and ammonium sulfate. Besides the choice of fertilizer nitrogen source related to N, to adjust the timing of nitrogen application at the time of greatest demand increased demand will increase crop production efficiency In view of this, six experiments were carried out from May 2009 to April 2010. These experiments were mainly aimed at evaluating the response of canola to nitrogen sources and application methods (seeding and / or coverage) of nitrogen fertilizer. All experiments were conducted in the experimental units at the Catholic University of Paraná - PUCPR - Toledo campus. To attend the responses of canola relative to rates and N sources were implanted three experiments in randomized blocks in a 7x2 factorial arrangement, consisting of seven levels of nitrogen at sowing (0, 20, 40, 60, 80, 100 and 120 kg ha -1) and two N sources (ammonium sulphate and urea), with four replications. To attend the responses of canola on the forms of nitrogen application and nitrogen sources were implanted over three experiments, which are conducted in randomized blocks in a 5x2 factorial arrangement consisting of five forms of nitrogen in the seeding and / or in coverage, respectively (0 and 0, 120 and 0, 0 and 120, 40 and 80, 80 and 40 kg N ha-1) and two nitrogen sources (ammonium sulphate and urea), with four replications. The coverage fertilization was performed in stage B4. The six experiments were carried out in three production cycles, two experiments in each cycle, corresponding to the following sowing dates: cycle 1: 12/05/2009; cycle 2: 20/06/2009 and cycle 3: 23/04 / 2010. All treatments received a fertilizer equivalent to 300 kg ha-1 00-25-25 formulation, each plot received the amount of nitrogen corresponding to the predetermined treatment. For the six experiments were evaluated the basal diameter, plant height, number of plants m-2, dry leaves, dry weight of stem + petioles, inflorescence dry mass, total plant dry mass, leaf area, area ratio of leaf, mass of pods per plant, weight per pod, weight of grains per pod, thousand grain weight, yield, leaf N content, protein and oil content in grain and oil yield per hectare. The results show that the variables were not influenced by sources of nitrogen fertilizer, ammonium sulfate and urea, for any of the six experiments conducted. The response to N rates influence these variables measured, and the higher productivity achieved with 88 kg ha-1 N. The increase of N doses promotes an increase in the protein reducing therefore the oil content in grains. The forms of nitrogen application also influenced the variables measured, and the best results achieved by the split of applying fertilizer at planting one-third and two-thirds coverage (40 and 80 kg N ha-1) / O termo canola é um acrônimo de CANadian Oil Low Acid e foi adotado como padrão para indicar baixos teores de ácido erúcico e glucosinolatos. De um modo geral, os solos tropicais apresentam baixa disponibilidade de nitrogênio (N) em função dos baixos estoques de matéria orgânica, exigindo o fornecimento externo de N para suprir as demandas da cultura. Dentre as principais fontes de N utilizados na cultura da canola estão os adubos nitrogenados uréia e sulfato de amônio. Além da escolha do adubo nitrogenado relacionado à fonte de N, ajustar o momento da aplicação do N ao momento de maior demanda da cultura aumenta a eficiência de produção. Visando instrumentar decisões relativas a estas alternativas de manejo, foram desenvolvidos quatro experimentos no período de maio de 2009 a abril de 2010. Estes experimentos tiveram como principal objetivo avaliar a resposta da canola a fontes, doses e momento de aplicação do N em Toledo Pr. Todos os experimentos foram conduzidos na unidade experimental da Pontifícia Universidade Católica do Paraná PUCPR - campus Toledo. Para quantificar as respostas da canola relativas a doses e fontes de N foram implantados dois experimentos de blocos casualizados, em esquema fatorial 7x2, constando de sete doses de N na semeadura (0; 20; 40; 60; 80; 100 e 120 kg ha-1 de N) e duas fontes de N (sulfato de amônio e uréia), com quatro repetições. Para quantificar as respostas da canola relativas ao momento de aplicação e às fontes de N foram implantados mais dois experimentos, sendo estes conduzidos em blocos casualizados, em esquema fatorial 5x2, constando de cinco combinações de momento de aplicação do N, na semeadura e/ou em cobertura, respectivamente (0 e 0; 120 e 0; 0 e 120; 40 e 80; 80 e 40 kg ha-1 de N) e duas fontes de N (sulfato de amônio e uréia), com quatro repetições. A adubação em cobertura foi realizada no estádio B4. Os quatro experimentos foram implantados em duas épocas de semeadura: 12/05 e 23/04. Todos os tratamentos receberam a adubação correspondente a 300 kg ha-1 de N, P2O5 e K2O na formulação 00-25-25 aplicado na semeadura, além da quantidade de N correspondente ao tratamento pré-estabelecido. Nos quatro experimentos foram avaliados o diâmetro basal, altura de planta, número de plantas m-2, massa seca de folhas, massa seca de caule+pecíolo, massa seca de inflorescência, massa seca da parte aérea, área foliar, razão de área foliar, massa de síliquas por planta, massa por síliqua, massa de grãos por síliqua, massa de mil grãos, produtividade, teor de N foliar, teor de proteína e óleo nos grãos e rendimento de óleo por hectare. Os resultados obtidos mostram que as variáveis avaliadas não foram influenciadas pelas fontes de N utilizadas, sulfato de amônio e uréia, para nenhum dos quatro experimentos conduzidos. Quanto à resposta às doses de N estas influenciaram as variáveis mensuradas, sendo a maior produtividade alcançada com 88 kg ha-1 de N. O aumento nas doses de N promove um incremento nos teores de proteína reduzindo, por consequência o teor de óleo nos grãos. O momento de aplicação do N também influenciou as variáveis mensuradas, sendo os melhores resultados alcançados pelo parcelamento da adubação aplicando-se um terço na semeadura e dois terços em cobertura (40 e 80 kg ha-1 de N)

The purpose of this research was to study the synthesis and remodeling of extracellular matrix (ECM) by fibroblasts with special emphasis on the culture environment (media composition and initial ECM composition) and the resulting mechanical integrity of the ECM. This was investigated by culturing fibroblasts for 3 weeks in a variety of culture conditions consisting of collagen gels, fibrin gels, or media permissive to the self-production of ECM (Cell-Derived Matrix), and quantifying the mechanics of the resulting ECM. The mechanical characteristics were related to the biochemistry of the resulting ECM, notably in terms of collagen accumulation and collagen fibril diameters. The ultimate tensile strength (UTS) of the collagen gels and fibrin gels at the end of the 3-week period was 168.5 ± 43.1 kPa and 133.2 ± 10.6 kPa, respectively. The ultimate tensile strength of the cell-derived matrices was 223.2 ± 9 kPa, and up to 697.1 ± 36.1 kPa when cultured in a chemically-defined medium that was developed for the rapid growth of matrix in a more defined environment. Normalizing the strength to collagen density resulted in a UTS / Collagen Density in these groups of 6.4 ± 1.9 kPa/mg/cm3, 25.9 ± 2.4 kPa/mg/cm3, 14.5 ± 1.1 kPa/mg/cm3, and 40.0 ± 1.9 kPa/mg/cm3, respectively. Cells were synthetically more active when they produced their own matrix than when they were placed within gels. The resulting matrix was also significantly stronger when it was self-produced than when the cells rearranged the matrix within gels that corresponded to a significantly larger fraction of non-acid and pepsin extractable collagen. These studies indicate that cell-derived matrices have potential both as in vitro wound healing models and as soft connective tissue substitutes.