A mandioca (Manihot esculenta) é uma espécie tropical que se destaca como fonte de alimento para os países em desenvolvimento, devido à grande quantidade de amido contido em suas raízes. Estudos indicam que o centro de origem e de domesticação da mandioca é na Amazônia brasileira, mas grande parte da diversidade genética dessa cultura é desconhecida. Este estudo baseou-se na caracterização da diversidade genética no estado de Mato Grosso (MT), especificamente nos municípios de Cáceres, Porto Estrela e Santo Antônio do Leverger, na Baixada Cuiabana. Os genótipos foram provenientes de roças de agricultores tradicionais. Esses campos são considerados como unidades evolutivas para a mandioca. Neste estudo, fizemos uma caracterização de 211 genótipos coletados em 40 roças, em 10 comunidades, nos três municípios citados acima. Essa caracterização foi realizada utilizando 14 locos microssatélites. Encontramos um alto nível de heterozigosidade observada (Ho = 0,587) e diversidade gênica (He = 0,525), enquanto a maior parte da diversidade genética foi encontrada dentro dos campos de roça (92%). Houve uma separação entre o município de Santo Antônio do Leverger e os municípios de Cáceres e Porto Estrela, provavelmente devido à maior distância geográfica e a proximidade entre os dois últimos municípios. A variabilidade intravarietal, detectada entre as etnovariedades que compartilham o mesmo nome popular, foi elevada (97%). Na análise de agrupamento não se encontrou nenhum agrupamento de genótipos classificados dentro de uma etnovariedade, confirmando os resultados da Analise de Variância Molecular (AMOVA). Finalmente, na análise de riqueza alélica, níveis muito elevados foram observados na área de estudo. Esta alta diversidade encontrada, provavelmente se deve ao fato de MT ser considerado como uma das áreas de centro de origem da espécie. No resultado de áreas prioritárias para conservação genética, observou-se que o município de Santo Antonio do Leverger seria considerado como uma área prioritária para a conservação in situ, devido à alta diversidade genética encontrada, e pela concentração de freqüências constantes para os alelos mais comuns e a presença de alelos privados fixados. / Cassava (Manihot esculenta) is a tropical species that stands out as a food source for developing countries due to the large amount of starch contained in its roots. Studies indicate that the center of origin and domestication of cassava is in the Brazilian Amazon, but much of the genetic diversity of this crop is unknown. This study was based on the characterization of genetic diversity in the state of Mato Grosso (MT), specifically in the municipalities of Cáceres, Porto Estrela and Santo Antonio do Leverger of Baixada Cuiabana. The genotypes originated from traditional farmer\'s swidden fields. These fields are considered as evolutionary units for cassava. In this study, we made a characterization of 211 genotypes collected in 40 swidden fields, in 10 communities, within the three municipalities mentioned above. This characterization was performed using 14 microsatellite loci. We found high levels of observed heterozygosity (Ho= 0.587) and gene diversity (He = 0.525), whereas most of the genetic diversity was found within the swidden fields (92%). There was a separation between the municipality of Santo Antonio do Leverger and the municipalities of Cáceres and Porto Estrela, which is probably due to the greater geographical distance and proximity between the last two municipalities. A high intravarietal variability (97%) was detected among the landraces sharing the same folk name. In the cluster analysis no clustering of genotypes classified within a landrace were found. Finally, in the analysis of allelic richness, very high levels were observed in the study area. This high diversity found would be given precisely by the fact that MT is considered one of the areas of the center of origin of the species. In the result of priority areas for genetic conservation we found that the municipality of Santo Antonio do Leverger would be considered as a priority area for in situ conservation due to the high genetic diversity found, and to the concentration of constant frequencies for the most common alleles and the presence of fixed private alleles.

A mandioca (Manihot Sculenta Crantz) é amplamente cultivada no Brasil e nos países tropicais do mundo por ser uma cultura de grande valor nutritivo e resistência às condições edafoclimáticas, servindo de segurança alimentar para vários países. A preponderância do cultivo no país é para abastecer mercados de consumo in natura de raízes e amido para várias agroindústrias. Apesar de sua grande aplicação, toda a cadeia agroindustrial nacional encontra obstáculos para sua expansão devido ao baixo rendimento de produção, alta demanda de mão de obra, cada vez mais escasso devido principalmente à atividade de grande esforço físico, falta de disponibilidade de máquinas especialmente para a colheita. O objetivo do trabalho foi descrever as etapas de colheita para identificar pontos de mecanização e propor alternativas de solução que se adequem melhor às necessidades da produção agrícola. Para isso, a pesquisa focou nas regiões produtoras de mandioca industrial dos estados do Paraná, Mato Grosso do Sul e São Paulo onde apresentam maior emprego de tecnologia na colheita, onde uma área de 10 a 20 hectares foi selecionada como público alvo. Aplicou-se a metodologia de projeto sistemático para a obtenção de informações através da realização de visitas técnicas e experimentos em campo, para estabelecer uma lista de requisitos a serem atendidos pela colheita mecanizada. Constatou-se da revisão da bibliográfica e visitas às áreas de produção que a operação de extração, destaque, e coleta das raízes seriam as principais oportunidades de estudo para a mecanização, onde a principal restrição ao desenvolvimento estaria nas operações de posicionamento e destaque das mesmas, em razão das raízes apresentarem certa aleatoriedade de geometria e dependência do ajuste das demais operações do cultivo e variedades. Nessa perspectiva, foram coletadas informações sobre a geometria das raízes para três diferentes variedades de mandioca em dois períodos de colheita. Para a proposição de uma solução para a colheita, foram estudados sistemas mecânicos alternativos para cada etapa do processo, gerando uma matriz morfologia que orientou a proposição de desenhos esquemáticos de cinco variantes de colhedoras. Por fim, selecionou-se a variante de um implemento de colheita composto por braços mecânicos com posicionamento assistido por operadores, onde o destaque das raízes deveria ser realizado por garras mecânicas para a separação da parte aérea das plantas ainda no solo. Com o objetivo de favorecer sua posterior extração através da análise de requisitos técnicos, econômicos, ambientais e sociais. A pesquisa visou contribuir com a cadeia da cultura da mandioca, com a formalização de informações e restrições para o projeto de colhedora ajustada para as condições nacionais, indicar alternativas de colhedoras a serem desenvolvidas e validadas em campo através de pesquisas posteriores. / Manihot (Manihot Sculenta Crantz) is widely cultivated in Brazil and in the tropical countries as a crop of great nutritional value and resistance to edaphoclimatic conditions, providing food security for several countries. The prevalence of the cultivation in the country is to supply markets of in natura consumption of roots and starch for several agroindustries. Despite its great application, the entire agroindustrial chain has obstacles to its expansion due to the low yield of production, high demand of labor, increasingly scarce due mainly to the arduous work, lack of availability of harvest machines. The objective of this work was to describe the harvesting stages to identify mechanization gaps and to propose alternative that best fit the farming production. The research focused on the industrial cassava production of the states of Paraná, Mato Grosso do Sul and São Paulo that holds the highest technology harvesting, and an area of 10 to 20 hectares was selected as the market target. A systematic design methodology was applied to obtain information through technical visits and field experiments, to establish a requirements list to appropriate answer the mechanized harvest. It was verified the bibliographical revision and visits that the operation of extraction, detach, and collection of the roots would be the main opportunities of the mechanization, and the main restriction to the development would be in the operations of positioning and detach, because the roots present a geometry randomness and dependence of the other operations adjustment of the crop and varieties. From this perspective, geometry information was collected for three different varieties of cassava in two harvest periods. The proposition a solution for the harvest, alternatives of mechanical systems was studied for each step of the process, creating a morphology matrix that guided to bring up the five harvesters schematic drawings. Finally, we selected the variant of a harvesting implement composed of mechanical arms with operatorassisted positioning, where the detach of the roots should be performed by mechanical claws to separate the plants aerial parts still in the soil, with the objective to facilitate after root extraction through the analysis of technical, economic, environmental and social parameters. Finally, this study aimed to contribute to the cassava culture chain, with the formalization of information and restrictions for the design of harvester machines adjusted for the national conditions, to indicate alternative to be developed and validated in the field through further works.

O cultivo da mandioca possui uma estreita relação com o campesinato brasileiro, estando presente entre seus cultivos desde sua gênese e ainda hoje é parte obrigatória da alimentação de vários segmentos da população brasileira das áreas rurais. Atualmente a maior parte da produção do tubérculo provém de áreas econômica e ecologicamente marginais sendo cultivado por meio de práticas agrícolas tradicionais, denominadas de agricultura de corte-e-queima. Porém, nos últimos anos a produção de mandioca tem apresentado uma contínua queda, principalmente no Estado de São Paulo, onde as transformações agrícolas foram mais intensas. Assim, é mediante a importância histórica do cultivo da mandioca entre os camponeses e a atual situação deste cultivo que colocamos nosso problema da seguinte forma: O declínio do cultivo da mandioca apresentado hoje não é um fenômeno recente, mas sim histórico se iniciando em outras épocas. Assim nosso objetivo principal é localizar as bases históricas do declínio do cultivo deste tubérculo entre os camponeses do Estado de São Paulo. Para atingir nosso objetivo adotamos o referencial teórico-metodológico da Historia Ambiental, que nos fornece elementos para fazer esta análise na perspectiva das relações entre as sociedades humanas e o mundo natural, usando para isso dados de diversas áreas como a Economia, a Antropologia, a Arqueologia, a Ecologia, além da História Social e Econômica. / The culture of the cassava has a narrow relationship with the Brazilian small rural culture, being present among its cultures since its genesis and until today it is a mandatory part of the feeding in some segments of the Brazilian population in the agricultural areas. Currently most of the tubercle production comes from economic and ecologically outskirt areas being cultivated through traditional agriculturists methods, called slash and burn agriculture. However, during the last years the cassava production has presented a continuous fall, mainly in the São Paulo state, where the agricultural transformations had been more intense. Thus, due the historical importance of the cassava culture between the peasants and the current situation of this culture, we place our problem on the following form: The current decline of the cassava culture is not a recent phenomenon, but historical and initiating at other times. Thus our main objective is to locate the historical bases of the decline of this tubercle culture among the peasants of the Sao Paulo state. To reach our objective we adopt the theoretician-methodological referential of the Environmental History, that supplies us elements to make this analysis in the perspective of the relations between the human societies and the natural world, using for this data from several areas as the Economy, the Anthropology, Archaeology, the Ecology, and also Social and Economic History.

As mandiocas utilizadas na produção da farinha contêm elevadas concentrações de glicosídeos cianogênicos, compostos que, após degradação, liberam cianeto na forma de ácido cianídrico (HCN) conferindo toxicidade à raiz. O processamento adequado da mandioca, para produção da farinha, resulta na degradação dos glicosídeos cianogênicos e na obtenção de um alimento com baixo teor de cianeto, o que gera a hipótese de liberação de HCN durante o processo. Neste contexto, o presente estudo objetivou avaliar a exposição de trabalhadores de casas-de-farinha ao HCN proveniente da mandioca, assim como identificar possíveis alterações clínicas e laboratoriais associadas a tal exposição. Foram incluídas no estudo 4 casa-de-farinha localizadas no Agreste Alagoano, microrregião de Arapiraca. A determinação de HCN em amostras de ar foi realizada de acordo com o método analítico 6010 recomendado pelo NIOSH. Cada casa foi monitorada em três pontos: dois em zona respiratória e um em ponto estático. Um total de 36 trabalhadores voluntários do sexo masculino distribuídos nas 4 casas-de-farinha foram selecionados para o estudo. Cada participante foi submetido à coleta de urina, sendo uma amostra pré-jornada e outra amostra pós-jornada e a uma coleta de sangue pré-jornada. O teor de tiocianato (SCN-) urinário foi quantificado espectrofotometricamente, enquanto que as outras avaliações bioquímicas foram realizadas em laboratório clínico. Os resultados indicam que os trabalhadores de casas-de-farinha estão expostos, cronicamente, a níveis atmosféricos de HCN dentro de um intervalo de 0,464±0,02 a 3,328±3,85 mg/m3 no ambiente de trabalho. A comparação entre os níveis atmosféricos determinados e os Limites de Exposição Ocupacional estabelecidos pelo NIOSH e ACGIH indica que trabalhadores de casas-de-farinha, podem estar expostos a níveis de HCN capazes de causar efeitos adversos à saúde. Os níveis médios de tiocianato urinário em mg/g de creatinina (10,62 - pré- jornada e 8,76 pós - jornada), foram significativamente superiores ao valor de referência para não fumantes e à média obtida no laboratório contratado para análise de SCN-, referente ao período de 2008 a 2010. Os resultados dos exames laboratoriais indicaram aumento nos níveis séricos de fosfatase alcalina nos trabalhadores de casas-de-farinha expostos ao HCN, com uma prevalência de 93,3%. Os trabalhadores foram submetidos ao exame clínico e não foram detectadas alterações características de exposição ao HCN. / Cassava used for flour production contains high amounts of cyanogenic glycosides, compounds that, after degradation, release hydrogen cyanide (HCN) which provide toxicity to these type of root. A suitable cassava processing results in the degradation of cyanogenic glycosides and in the production of a safety flour for consumption as food, which generates the hypothesis of HCN release during the process. In this context, the present study aimed to evaluate the HCN exposure of workers engaged in cassava processing, as well as, to identify possible clinical and laboratory alterations related to this exposure. It was included in the study 4 cassava processing facilities placed on Alagoas state, Brazil. It was conducted the determination of HCN in air samples according to the method 6010 proposed by NIOSH. Each industry was monitored in three points: two on workers respiratory zone and one static. A total of 36 male volunteers, distributed between the 4 facilities were included in the study. Each participant was submitted to urine sampling, been one before and other after work shift, and to one blood sampling before work shift. Urinary thiocyanate (SCN-) was spectrophotometrically determined, whereas the remaining biochemical evaluation was conducted in a commercial clinical laboratory. The results indicated that the cassava processors are chronically exposed to HCN at levels between 0,464±0,02 and 3,328±3,85 mg/m3, in the work environment. The comparison between the levels determined at the present study with the Occupational Exposure Limits (OEL) established by NIOSH and ACGIH indicated that cassava processors may be exposed to HCN levels capable of causing adverse health effects. The mean levels of urinary thiocyanate (10,62 - before shift and 8,76 - after shift), were significantly higher than the reference value for non smokers and also for the history mean obtained from the laboratory employed for SCN- analysis, during 2008-2010. The results of laboratorial evaluation indicated increase in the serum activity of alkaline phosphatase in cassava processors exposed to HCN, with a prevalence of 93,3%. The workers were submitted to clinical evaluation and it was not detected any alteration typical of HCN exposure.

Le procédé de transformation des racines de manioc en gari reste la plupart du temps artisanal et dépendant du savoir-faire des opératrices. Étant constitué d’une suite d’opérations unitaires (râpage, fermentation/pressage, tamisage et cuisson), il est nécessaire de déterminer les opérations-clefs déterminantes de la qualité du produit. Ainsi, dans ce travail, le procédé a été analysé dans sa continuité au travers du suivi de réponses biochimiques, granulométriques et hydro-texturales du produit durant sa transformation. L’objectif du travail de thèse a été dans un premier temps de développer des outils et méthodes permettant le suivi des états physiques et biochimiques du produit tout au long de sa transformation à l’échelle laboratoire. Cette démarche a permis de dégager certains mécanismes contribuant à la transformation du produit. Il a été mis en évidence le drainage d’une partie du liquide intra-cellulaire lors du pressage ainsi que deux mécanismes d’agglomérations successifs lors de l’élaboration du gari. Les résultats et les mécanismes déduits des observations réalisées à l’échelle laboratoire ont par la suite été confrontés à ceux obtenus sur le terrain (Bénin) dans des conditions moins maîtrisées et sous l’effet d’un changement d’échelle. L’opération de cuisson, à la fois très contraignante et ressortant comme une opération unitaire clef a été, par la suite, plus particulièrement étudiée. Pour cela, le comportement (choix et gestes) de deux opératrices a été enregistré de façon à mettre en évidence le rôle de l’opératrice lors de la cuisson. L’ensemble des résultats montrent que la qualité des garis repose en grande partie sur le savoir faire de l’opératrice. Il ressort cependant que les critères de qualité du gari qui guide l’opératrice lors de la cuisson et la conduisent à ajuster son comportement sont, bien sûr, ceux qui lui sont accessibles (couleur, taille, …), mais ne sont pas suffisants pour atteindre teneurs en composés cyanogénique résiduels recommandées par le Codex Alimentarius de la FAO. / The cassava process of converting cassava roots into gari remains mostly artisanal and depends on the know-how of the operators. As it consists of a series of unit operations (grating, fermentation/pressing, sieving and cooking), it is necessary to determine the key operations that determine the quality of the product. Thus, in this work, the process was analyzed in its continuity through the monitoring of biochemical, granule size and hydro-textural responses of the product during processing. The objective of the thesis work was initially to develop tools and methods to monitor the physical and biochemical states of the product throughout its processing on a laboratory scale. This approach has made it possible to identify some of the mechanisms that contribute to the elaboration of the product. It was found that part of the intracellular liquid drained during pressing and two successive agglomeration mechanisms were identified during the preparation of the gari. The results and mechanisms derived from laboratory scale observations were then compared with those obtained in the field (Benin) under less controlled conditions and scaling effect. The cooking operation, which is both very constraining and emerging as a key unitary operation, was then more particularly studied. For this purpose, the performance (choice and gestures) of two operators was recorded in order to highlight the role of the operator during the cooking process. All the results show that the gari quality is largely based on the operator's know-how. However, it appears that the product quality criteria that guide the operator during cooking lead her to adjust her practices are, of course, those that are accessible to her (colour, granule size, ...), but are not enough to reach the levels of residual cyanogenic compounds recommended by the FAO Codex Alimentarius.

Thesis (Master of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, 2018. / Renewable energy security for the future and better use of natural resources are key challenges that can be concurrently managed by a practical anaerobic co-digestion approach in the production of methane. For this study, co-digestion of cassava and winery waste was investigated for the production of biogas. Cassava biomass is a good substrate for biogas production due to its high carbohydrate yield per hectare (4.742 kg/carb) than most plants. Winery wastes constitute a lot of challenge in South Africa due to high amounts currently being dumped at landfills. Due to the chemical properties of the two substrates, it is envisaged that their co-digestion will produce more biogas than use of a single substrate. Biomethane potential (BMP) tests were carried out in a batch, mesophilic (37 °C±0.5) reactor using cassava and winery waste singly and in combination at a ratio of 1:1 and ran for 30 days. Biogas optimization was also evaluated. The optimal conditions for methane production from anaerobic co-digestion of cassava biomass and winery solid waste using response surface methodology (RSM). The effects of temperature, pH and co-substrate ratios on the methane yield were explored. A central composite design technique was used to set-up the anaerobic co-digestion experiment was determined. Once the optimized values were established, biogas production from co-digestion of cassava biomass with winery waste was investigated using a single-stage 5 L mesophilic batch digester and the microbial dynamics inside the digester during co-digestion of cassava and winery waste in the single-stage 5 L mesophilic batch digester. The samples were collected on days 1, 15 and 30 of the anaerobic digestion period and DNA extracted from them while 16sRNA bacterial sequencing was performed. The results for the BMP tests showed that cumulative methane yield for cassava, winery waste and in combination were 42, 21 and 38 mLCH4 respectively. It was concluded that biogas production from anaerobic digestion was dependent on many factors such as pH, substrate properties and the ratio of different feedstocks used during co-digestion. The results from the optimization study were pH 7, temperature of 35 °C±0.5 and co-digestion ratio of 70:30 cassava to winery waste. The maximum methane yield of 346.28 mLCH4/gVSadded was predicted by the quadratic model at the optimal temperature of 35 oC±0.5, pH of 7 and 70:30 ratio of cassava biomass to winery solid waste. Experimental results showed a close fit but higher methane yield (396 mLCH4/gVSadded) than predicted values as indicated by the coefficient of determination (R2) value of 0.9521. The response surface model proved successful in the optimization process of methane yield. The single-stage 5L mesophilic batch digester with a co-substrate ratio of 70:30 cassava to winery waste produced a total of 819.54 mL/gVS biogas with a 62 % methane content. The study of microbial community dynamics showed the presence of the bacteria that is responsible for each stage of anaerobic digestion. The study concluded that both winery waste and cassava substrates were favourable for biogas production and most underprivileged people in the rural areas with no access to electricity can produce & utilise it.

Este trabalho objetivou estudar e descrever as relações multiespécies que contribuem para que se mantenha a existência da mandioca junto aos Pataxó no entorno do Monte Pascoal, no Sul da Bahia, num contexto de transformação e \"modernização\" da agricultura local. Ele foi inspirado na ideia de que a diversificação e manutenção da mandioca se dá dentro de contextos históricos de seu envolvimento contínuo com diversos seres e coisas, ou seja, mediante suas ações ambientalmente situadas. A hipótese central levantada é que a diversidade de mandiocas existentes ocorre através de um conjunto de relações sócio-ecológicas no qual os humanos são parte importante. Através da metodologia proposta pela etnografia multiespécie foram apresentadas primeiramente cinco histórias no intuito de mostrar como a mandioca está envolvida em relações múltiplas com os Pataxó e outros seres, que envolvem afetos, memórias, conhecimentos, práticas, política, nas quais ela se destaca como uma espécie companheira com a qual se tem coevoluido. A partir dessas histórias, foram indicadas e descritas as temporalidade de seu modo de vida e as práticas que se destacaram como importantes na existência e permanência dessa planta na região, evidenciando as assembleias que se formaram e suas consequências na vida da mandioca e de seus companheiros Pataxó. O estudo aponta para a resiliência na diversidade de mandioca ao longo do tempo na região, porém em menor quantidade e qualidade, evidenciando uma precarização de determinadas relações, as quais passam a demandar atenção ao se pensar na elaboração de estratégias de conservação da agrobiodiversidade junto com os Pataxó no Monte Pascoal. / This work aimed to study and describe the multi-species relationships that contribute to maintain the existence of cassava with the Pataxó surrounding the Monte Pascoal, in Southern Bahia, in a context of transformation and \"upgrading\" of local agriculture. It was inspired by the idea that diversification and maintenance of cassava takes place within historical contexts of their continuing involvement with various beings and things, that is, through its environmentally situated actions. The central hypothesis is that the diversity of cassava can not be seen only as genetic resources (which suffer natural selection) not only as the result of human management (artificial selection and the symbolic constructions), but as a set of relationships socio- ecological in which humans are an important part. Through the methodology proposed by the multispecies ethnography were presented five stories in order to show how cassava is involved in multiple relationships with the Pataxó and other beings, involving emotions, memories, knowledge, practices, politics, in which it stands as a specie partner with who it has co-evolved. From these stories was demonstrated and described the temporality of their way of life and practices that stood out as important in the existence and permanence of this plant in the region, highlighting the meetings that formed and its consequences in cassava life and his companions Pataxó. The study points to the resilience in cassava diversity over time in the region, but in smaller quantities and quality, showing a precariousness of certain relationships, which begin to demand attention when thinking about the development of the agro-biodiversity conservation strategies with Pataxó in Monte Pascoal.

Orientador: Marcelo de Almeida Silva / Banca: Fernando Broetto / Banca: Adalton Mazetti Fernandes / Banca: Carlos Feltran / Banca: José Rodrigues Magalhães Filho / Resumo: Essa pesquisa teve como objetivo avaliar as características fisiológicas, bioquímicas e os componentes da produção da mandioca de mesa IAC 576-70 sob deficiência hídrica em diferentes fases fenológicas da cultura. O experimento foi conduzido em cultivo protegido, em delineamento inteiramente casualizado e esquema fatorial 3x3, constituído por três fases fenológicas (de 90 a 180; de 180 a 270 e de 270 a 360 dias após o plantio, DAP) e três tensões de água no solo (-10, -40 e -70 kPa), com cinco repetições. As manivas-sementes foram plantadas em caixas com 0,30 m3 de solo e a umidade do solo foi monitorada por tensiômetros, mantendo-se o solo na capacidade de campo até o início dos tratamentos. As características fisiológicas e bioquímicas foram descritas apenas na fase de 90 a 180 DAP, pois a perda natural de folhas no período do inverno na região comprometeu as avaliações nas demais fases. Aos 135 DAP a deficiência hídrica aumentou 42,9% o teor de clorofila total nas plantas sob tensão de -70 kPa. O potencial da água, o teor relativo de água e o extravasamento de eletrólitos nas folhas não foram alterados pelas tensões de água no solo. Houve acréscimo de 16,0% na densidade estomática foliar nas tensões de -40 e -70 kPa, enquanto que a eficiência quântica efetiva do fotossintema II e a taxa de transporte de elétrons foram reduzidas. As plantas sob as menores tensões de água no solo aumentaram 15,4% os teores de açúcares solúveis nas folhas. As atividades das enzimas antioxidan... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This research aimed to evaluate the physiological and biochemical characteristics and yield components of sweet cassava plants IAC 576-70 under water deficit in different phenological phases of the crop. The experiment was carried out in a completely randomized design and factorial scheme 3 x 3, consisting of three phenological stages (90 to 180, 180 to 270 and 270 to 360 days after planting DAP), and three soil water tension (-10, -40 and -70 kPa), with five replicates. The stem cuttings were planted in boxes with 0.30 m3 of soil and the soil moisture was monitored by tensiometers, keeping the soil in the field capacity until the beginning of the treatments. The physiological and biochemical characteristics were described only in the phenological phase 90 to 180 DAP, because the natural loss of leaves in the winter period in the region compromised the evaluations in the other phases. At 135 DAP the water deficit increased by 42.9% the total chlorophyll content in plants under tension of -70 kPa. The water potential, relative water content and electrolyte leakage in the leaf were not altered by soil water tension. There was an increase of 16.0% in leaf stomatal density under tensions of -40 and -70 kPa, while the effective quantum efficiency of photosystem II and the rate of electron transport were reduced. The plants under the tensions of -40 and -70 kPa increased the soluble sugar content of the leaves by 15.4%. The activities of antioxidant enzymes were more accentuated at... (Complete abstract click electronic access below) / Doutor

Cassava (Manihot esculenta Crantz Family Euphorbiaceae) is an important tropical food crop. However, harvested cassava roots have a shelf-life of only days due to post-harvest physiological deterioration (PPD). Within 1-3 days of harvesting, the roots show blue-black vascular streaking and are unpalatable. PPD includes altered gene expression and the accumulation of hydroxycoumarin secondary metabolites, e.g. scopoletin and esculetin, and their respective glucosides scopolin and esculin. In this research several important aspects of the biosynthesis of these phytochemically important hydroxycoumarins were resolved. Stable isotopically labelled intermediates on the postulated biosynthetic pathways of scopoletin were fed to cassava cubes and PPD was allowed to occur. Ethanolic extracts of these deteriorated roots were separated (HPLC) and analysed (HRESI-MS). Incorporation (in both scopoletin and scopolin) of only 3 deuterons from E-cinnamic-2,3,2',3',4',5',6'-d7 and E-cinnamic-3,2',3',4',5',6'-d6 is strong support that the E-Zisomerisation step is enzymatic and not photochemical. There are three hypothetical pathways for the biosynthesis of scopoletin via: 2',4'-dihydroxycinnamate, caffeate, or ferulate. High incorporation of label from p-coumaric-2-13C, caffeic-2-13C and ferulic-2-13C acids was observed into labelled scopoletin and scopolin while there was only a small incorporation from 18O-umbelliferone and 18O-esculetin. We conclude that the major biosynthetic pathway to scopoletin and scopolin is via ferulic acid. C18O2-enrichment of E-cinnamic and ferulic acids and feeding gave scopoletin containing only one 18O-labelled oxygen atom. Therefore the lactonisation step is through o-hydroxylation and not via a postulated spirolactone-dienone intermediate. These results were confirmed by feeding experiments in an atmosphere of 18O2-air which showed that the major isotopic peak was 18O3-enriched scopoletin. Three glucosyltransferases were isolated and identified from a cassava PPDrelated cDNA library. These genes are expressed in the cassava storage root during PPD and they are also expressed in the fresh root. While one of these glucosyltransferases was novel, two had previously been isolated from cassava cotyledons.

Submitted by JOSIANE SANTOS DE OLIVEIRA (josianeso) on 2018-10-01T16:46:40Z No. of bitstreams: 1 Miguel de Nazaré Brito Picanço_.pdf: 14273602 bytes, checksum: cf9335e64c515c6076a8654d053e639d (MD5) / Made available in DSpace on 2018-10-01T16:46:40Z (GMT). No. of bitstreams: 1 Miguel de Nazaré Brito Picanço_.pdf: 14273602 bytes, checksum: cf9335e64c515c6076a8654d053e639d (MD5) Previous issue date: 2018-05-29 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Esta etnografia se inscreve nos estudos contemporâneos que tratam da cultura material e da vida coletiva, considerando as trajetórias e os movimentos de algumas espécies do mundo natural cultivadas por indivíduos. Assim, busco estudar as ressignificações que estão acontecendo na cultura material contemporânea, numa ordem de interação entre elementos, coisas e espécies da natureza que compõem essa cultura material, e suas experiências com humanos e não humanos (Ingold, 2015, 2012; Latour, 2012; Gell, 2005). Por meio de incursões etnográficas, pautadas em observações participantes, conversas formais e informais, estudei as trajetórias e os movimentos da mandioca e suas rotas e desvios (Appadurai, 2008) no e além do território brasileiro, com centralidade no estado do Pará, onde ela povoa um emaranhado de práticas comerciais, comensais e religiosas com e entre os sujeitos que a cultivam, estabelecendo-se como alimento primordial e como objeto na constituição de experiências que povoam o cotidiano dos paraenses. Portanto, nesta investigação objetivou-se analisar e descrever as experiências vivenciadas pela mandioca com os humanos que habitam no texto da pesquisa, e destes com ela. Para tanto, nesta viagem me dispus a seguir os materiais e pessoas que dão concretude às experiências supramencionadas com o intuito de: etnografar os processos que culminam com a produção, consumo e singularização (Kopytoff, 2008) dos descendentes da mandioca, assim como reconhecer como são negociadas e estabelecidas essas experiências. / This ethnography is inscribed in contemporary studies dealing with material culture and collective life, considering the trajectories and movements of some species of the natural world cultivated by individuals. Thus, I seek to study the re-significances that are taking place in contemporary material culture, in an order of interaction between the elements, things and species of nature that make up this material culture, and their experiences with humans and non-humans (Ingold, 2015, 2012; Gell, 2005). Through ethnographic incursions, based on participant observations, formal and informal conversations, I studied the trajectories and movements of cassava and its routes and deviations (Appadurai, 2008) in and beyond the Brazilian territory, with centrality in the State of Pará, where it populate a tangle of commercial, commensal, and religious practices with and among the subjects who cultivate it, establishing itself as a primordial food and as an object in the constitution of experiences that populate the daily life of the Paraense. Therefore, this research aimed to analyze and describe the experiences of cassava with the humans that inhabit the text of the research, and of these with it. To this end, I set out to follow the materials and people that give concrete expression to the above mentioned experiences in order to: ethnograph the processes that culminate with the production, consumption and singularization (Kopytoff, 2008) of the descendants of cassava, as well as recognize as these experiences are negotiated and established.