LOBO, A. K. M. Photosynthesis regulation by sucrose metabolism under water deficit and source-sink alterations in sugarcane. 2016. 118 f. Tese (Doutorado em Bioquímica)-Universidade Federal do Ceará, Fortaleza, 2016. / Submitted by Anderson Silva Pereira (anderson.pereiraaa@gmail.com) on 2017-01-03T20:20:30Z No. of bitstreams: 1 2016_tese_akmlobo.pdf: 4541762 bytes, checksum: e3450d87e286b1a5213eb866921b6c94 (MD5) / Approved for entry into archive by Jairo Viana (jairo@ufc.br) on 2017-01-09T21:32:52Z (GMT) No. of bitstreams: 1 2016_tese_akmlobo.pdf: 4541762 bytes, checksum: e3450d87e286b1a5213eb866921b6c94 (MD5) / Made available in DSpace on 2017-01-09T21:32:52Z (GMT). No. of bitstreams: 1 2016_tese_akmlobo.pdf: 4541762 bytes, checksum: e3450d87e286b1a5213eb866921b6c94 (MD5) Previous issue date: 2016 / Water deficit stress is the major limiting factor for plant growth and development, constraining food production. In order to survive in such dry conditions, many biochemical and physiological changes must be triggered by plants. In general, the responses to drought are loss of water content, reductions of stomatal conductance and photosynthesis and increase of carbohydrates. Soluble sugars play a key role in plant metabolism, acting as substrates and modulators of enzyme activity in carbon-related pathways and controlling the expression of different genes related to carbon, lipid and nitrogen routs. However, the mechanisms involved with photosynthesis down-regulation by drought and sugars in C4 plants are not fully understood. The aim of this study was to investigate how drought and source-sink perturbation regulate photosynthesis in sugarcane plants. Therefore, two studies were conducted with sugarcane plants with four months old cultivated under greenhouse conditions. In the first study sugarcane plants (cv. IACSP94-2094) were subjected to water deficit for 5 days (WD) with concomitant spraying of 50 mM exogenous sucrose (WD + Suc). While in the second study source-sink relationship was perturbed in two sugarcane cultivars (cv. IACSP94-2094 and cv. IACSP95-5000) by imposing partial darkness, spraying 50 mM exogenous sucrose and their combination for 5 days. The negative effects of WD in the gas exchange and photochemical parameters were aggravated by exogenous sucrose. Photosynthesis reductions were related to both stomatal and biochemical limitations, but exogenous sucrose intensified metabolic restrictions mainly through down-regulation of Rubisco initial activity and PSII effective quantum efficiency in drought-stressed plants. In addition, Rubisco activation state was decreased by WD + Suc, indicating perhaps that the activity of this enzyme was reduced by tight-binding inhibitors, such as sugars phosphates. Sucrose metabolism enzymes and sugars amount were also differently altered by WD and WD + Suc in leaves, sheath and stalk in WD and WD +Suc plants. Interestingly, Sucrose/hexose ratio decreased in both leaf and sheath whereas it was increased in stalk, suggesting that sucrose and related sugars were intensely metabolized and transported in drought-stressed plants. In well-watered conditions, photosynthesis was inhibited by sucrose spraying in both genotypes, through decreases in maximum Rubisco carboxylation rate (Vcmax), initial slope of A-Ci curve (k), stomatal conductance (gs) and ATP production driven by electron transport (Jatp). The partial darkness and sucrose spraying combination did not change photosynthesis in both genotypes. Significant increases in Vcmax, gs and Jatp and marginal increases in k were noticed when combining partial darkness and sucrose spraying compared with sucrose spraying alone. Altogether, these results suggest that CO2 assimilation impairment is aggravated by exogenous sucrose in drought-stressed plants. This limitation was mainly related to biochemical restrictions, specially associated with Rubisco initial activity and PSII quantum efficiency. In contrast, in vitro PEPCase activity and amount were increased in sucrose-treated plants, suggesting that C4 cycle efficiency was reduced in vivo by C3 cycle inhibition under drought conditions. Moreover, sucrose amount was increased in the stalk, suggesting the feedback regulation from stalk to source leaves in drought-stressed plants. Our data also revealed that increases in sink strength due to partial darkness offset the inhibition of sugarcane photosynthesis caused by sucrose spraying, enhancing the knowledge on endogenous regulation of sugarcane photosynthesis through the source-sink relationship. / A deficiência hídrica é o principal fator limitante para o crescimento e desenvolvimento das culturas. Para sobreviver nessas condições adversas, várias modificações bioquímicas e fisiológicas são desencadeadas pelas plantas. Em geral, os efeitos da seca em plantas são diminuição do status hídrico, reduções da condutância estomática, fotossíntese e crescimentos e aumentos nos níveis de carboidratos. Os açúcares solúveis desempenham papéis chave no metabolismo das plantas, atuando como substratos e moduladores da atividade enzimática em vias relacionadas com o carbono. Além disso, os açúcares controlam a expressão de genes associados com as rotas do metabolismo do carbono, lipídios e nitrogênio. Entretanto, os mecanismos envolvidos com a regulação negativa da fotossíntese por deficiência hídrica e açúcares em plantas C4 não estão totalmente entendidos. O objetivo deste estudo foi investigar como a deficiência hídrica e perturbações na relação fonte-dreno regulam a fotossíntese em plantas de cana-de-açúcar. Dois estudos foram conduzidos com plantas de cana-de-açúcar com quatro meses de idade cultivadas sob condições de casa de vegetação. No primeiro estudo, plantas de cana-de-açúcar (cv. IACSP94-2094) foram submetidas a deficiência hídrica por 5 dias (WD) com subsequente aplicação de sacarose exógena 50 mM (WD + Suc). Enquanto que no segundo estudo a relação fonte-dreno foi perturbada em duas cultivares de cana-de-açúcar (cv. IACSP94-2094 and cv. IACSP95-5000) pela imposição parcial de sombreamento, aplicação de sacarose exógena 50 mM e por suas combinações por 5 dias. Os efeitos negativos de WD nos parâmetros de trocas gasosas e fotoquímicos foram agravados por sacarose exógena. As reduções na fotossíntese foram relacionadas com limitações estomáticas e bioquímicas, porém a sacarose exógena intensificou as restrições bioquímicas principalmente por reduções na atividade inicial de Rubisco e eficiência quântica do PSII em plantas sob seca. Além disso, o estado de ativação de Rubisco foi inibido por WD + Suc, sugerindo que a atividade inicial dessa enzima foi possivelmente reduzida por inibidores que se ligam fortemente em seu sitio ativo, tais como açúcares fosfato. As enzimas do metabolismo de sacarose e a concentração de açúcares foram modificados diferentemente por WD e WD + Suc em folhas, bainha e colmo. Interessantemente, a relação sacarose/hexose decresceu em folhas e bainha, enquanto que no colmo essa relação aumentou, sugerindo que sacarose e outros açúcares relacionados foram intensamente metabolizados e transportados. Em condições irrigadas a fotossíntese foi inibida pela aplicação de sacarose nos dois genótipos, através de decréscimos da taxa máxima de carboxilação de Rubisco (Vcmax), inclinação inicial da curva A-Ci (k), condutância estomática (gs) e produção de ATP direcionada pelo transporte de elétrons (Jatp). A combinação de sombreamento parcial e sacarose não alterou a fotossíntese em ambos os genótipos. Significantes aumentos em Vcmax, gs, Jatp e k foram observados quando sombreamento parcial e sacarose foram combinados em comparação com plantas tratadas apenas com sacarose. Em conclusão, esses resultados sugerem que o impedimento da assimilação de CO2 é agravada por adição de sacarose exógena em plantas sob estresse hídrico. Essa limitação foi relacionada principalmente com restrições bioquímicas, especialmente associadas com reduções na atividade inicial de Rubisco e eficiência quântica do FSII. Em contraste, a atividade in vivo e concentração de PEPCase foram aumentadas em plantas tratadas com sacarose e estresse hídrico, sugerindo que a eficiência do ciclo C4 foi reduzida in vivo por inibições do ciclo C3 sob condições de seca. Além disso, o conteúdo de sacarose aumentou no colmo, indicando uma regulação de feedback do colmo para as folhas em plantas sob seca. Nossos dados revelam ainda que aumentos na força do dreno devido ao sombreamento parcial aliviaram os efeitos inibitórios na fotossíntese de cana-de-açúcar causados pela aplicação de sacarose, aumentando o conhecimento na regulação endógena da fotossíntese de cana-de-açúcar através da relação fonte-dreno.

Submitted by ANTONIO NEGRO (negro@ufba.br) on 2016-04-05T21:41:29Z No. of bitstreams: 1 2009 lara.pdf: 61749206 bytes, checksum: 89e3b71c814b7242afdfe6336a1c1787 (MD5) / Approved for entry into archive by Oliveira Santos Dilzaná (dilznana@yahoo.com.br) on 2016-04-12T16:00:03Z (GMT) No. of bitstreams: 1 2009 lara.pdf: 61749206 bytes, checksum: 89e3b71c814b7242afdfe6336a1c1787 (MD5) / Made available in DSpace on 2016-04-12T16:00:03Z (GMT). No. of bitstreams: 1 2009 lara.pdf: 61749206 bytes, checksum: 89e3b71c814b7242afdfe6336a1c1787 (MD5) / FAPESB / Esta dissertação conta a história de trabalhadores retirantes e engenheiros dentro das frentes de serviços de açudagem da Comissão de Obras Novas Contra as Secas, em 1915, levando em conta questões sobre a política e a atuação desta comissão e os conflitos decorrentes no processo da edificação das obras. A problemática da seca ganha visibilidade nacional depois da seca de 1877. Muitos discursos e ações surgiram depois desta estiagem prolongada, associando os problemas dos estados semiáridos (atraso, pobreza, miséria e etc.) à calamidade climática e tentando remediar seus problemas mediante obras hidráulicas. Em 1915, quando foi reconhecida oficialmente a seca, uma comissão intitulada Obras Novas Contra as Secas foi designada para combatê-la. Esta comissão deu início a várias construções. Eram preferidas as que possibilitassem o escoamento de água e ocupassem um grande número de retirantes com trabalho nas obras. Com base em pesquisas nas fontes de jornais cearenses sobre o período, relatório de serviços executados pela comissão em estudo, documentos técnicos diversos, correspondências, documentos oficiais e obras bibliográficas do período, é traçada a trajetória da construção de alguns açudes dessa comissão, tendo como principais atores: retirantes operários e engenheiros. De retirantes a trabalhadores, nos canteiros de obras de açudagem contra as secas, os operários agiram na reivindicação de meios que garantissem a sobrevivência, agregando diferentes experiências de trabalho, dentro das frentes de serviços. Enquanto os engenheiros, crentes na sua racionalidade científica, ficavam diante de uma luta a que não estavam acostumados: a calamidade da seca e os seus problemas sociais, o que também provocava embates. No entanto, as questões da seca de 1915 não se limitavam aos que se concentravam dentro das obras. Dentro desse contexto, outros sujeitos se envolveram na trama. Presidente do Estado e autoridades locais – prefeitos, vigários, latifundiários e outros atores da sociedade local –, na região Norte do Ceará, cidade de Sobral e proximidades, onde foram realizadas as obras, evidenciaram posturas e sentimentos diversos perante os retirantes da seca de 1915.within the service weir committee of New Works Against Drought in 1915, taking into account issues on policy and actions of this committee and the conflicts arising in the process of building the works. The problem of gaining visibility national drought after drought in 1877. Many speeches and actions that occurred after prolonged drought associated problems of state semi-arid (delay, poverty, misery and etc.). A climate disaster and trying to remedy its problems with hydraulic works. In 1915, when it was declared a drought, a committee was formed to combat this drought: New Works Against Drought. The committee began the various buildings. They were the favorite to enable the flow of water and occupy a lot of work with “migrants from the drought” in the works. Based on research on the sources of newspapers of the Ceará on time, report of services performed by the committee under study, several technical papers, correspondence, official documents and bibliographical works of the period is traced the trajectory of the construction of some dams that committee, with the main actors “migrants from the drought” and engineers. “Migrants from the drought” of the workers, an area of works of weirs against droughts, the workers claim to have acted in ways that ensure the survival, adding different experiences of working within the service front, while the engineers, believers in their scientific rationality, were front of a fight that was not used: the scourge of drought and its social problems, which have caused collisions. However, the issues of drought of 1915 were not limited to those that are concentrated in the works. Within this context, other subjects were involved in the plot. President of state and local authorities - mayors, vicar, landowners and other stakeholders of the local community - in the northern region of Ceará, and nearby city of Sobral, where the works were performed, demonstrated next to the attitudes and feelings “migrants from the drought” of 1915.

This thesis describes the importance and use of permanent grasslands, or more so-called energy grasses used in the energy sector. For our study we examined these three grasses: Ovsík vyvýšený (Arrhenatherum elatius), Sveřep horský (Bromus carharticus) and Bojínek luční (Phleum pratense). Another, the main task was to determine their resistance to drought. The results based on laboratory work, which between them compared the two variants. One was simulated normal emergence of the species and the second emergence stressed by lack of water. Based on these results, we conclude that we can not say that it would be a downright drought-resistant types. For the two studied species of grasses (Bojínek and Ovsík) are obvious differences in resistance to drought. Sveřep horský (variety - Tacit), however, proved to be the most drought-resistant species. While most sprouted out bojínek luční (variety - Sobol).

Master of Science / Department of Agronomy / Allan K. Fritz / Drought is known to be one of the most limiting abiotic stresses for wheat (Triticum aestivum L.) production, not only in the Midwest, but throughout the world. It is a complex issue and one that is difficult to screen for when breeding for new varieties. Hybrid wheat is one possible tool for breeders to use in order to make genetic gains towards better tolerance. The effectiveness of hybrid wheat as a tool to address regular periods of drought is a topic of continual discussion. The purpose of this study was to perform a comprehensive screening for drought tolerance comparing two different experimental hybrid entries to their parents. The hybrids were selected based on their good performance under drought in prior field trials. Plants were grown in PVC columns containing sensors that monitored growth media water content and matric potential. All plants were grown equally until heading. Drought treatment began 10 days post anthesis. Plants were observed until senescence/maturity. Several different agronomic characteristics were measured along with physiological traits that have previously been linked to drought tolerance. After completion of the screening, it was observed that the hybrid entries tended to fall between the two parents for a majority of the measurements. When comparing the hybrids to the parents overall, at least one parent outperformed its hybrid in every category. Parent line Parent B was one of the highest ranking genotypes for all measurements. Different drought mechanisms were observed across genotypes upon completion of the treatment. Further research is necessary to understand the hybrid response to drought when compared to pure line varieties.

abstract: Perceptions of climate variability and change reflect local concerns and the actual impacts of climate phenomena on people's lives. Perceptions are the bases of people's decisions to act, and they determine what adaptive measures will be taken. But perceptions of climate may not always be aligned with scientific observations because they are influenced by socio-economic and ecological variables. To find sustainability solutions to climate-change challenges, researchers and policy makers need to understand people's perceptions so that they can account for likely responses. Being able to anticipate responses will increase decision-makers' capacities to create policies that support effective adaptation strategies. I analyzed Mexican maize farmers' perceptions of drought variability as a proxy for their perceptions of climate variability and change. I identified the factors that contribute to the perception of changing drought frequency among farmers in the states of Chiapas, Mexico, and Sinaloa. I conducted Chi-square tests and Logit regression analyses using data from a survey of 1092 maize-producing households in the three states. Results showed that indigenous identity, receipt of credits or loans, and maize-type planted were the variables that most strongly influenced perceptions of drought frequency. The results suggest that climate-adaptation policy will need to consider the social and institutional contexts of farmers' decision-making, as well as the agronomic options for smallholders in each state. / Dissertation/Thesis / Masters Thesis Sustainability 2015

Drought-induced tree mortality is a phenomenon affecting many forest ecosystems and is predicted to increase under ongoing climate change. Forest stability partly depends on regeneration: the process of renewing mature forest with subsequent generations. As seedlings are more susceptible to drought effects than mature trees, mortality of the seedling bank can represent a major bottleneck controlling forest structure and species composition. Scots Pine (Pinus sylvestris L.) is the most widely distributed of the Pinus species, covering a broad latitudinal gradient of ecological conditions. The thesis aims to deepen understanding of drought-induced mortality, while analysing intra-specific variation in the phenotypic and metabolic profile of Pinus sylvestris seedlings subjected to drought stress. I also consider the relevance of the results to the broader conceptual framework of drought-induced mortality. The experiments utilise seeds from different populations of origin (provenances) across the north-south axis of the European range of Pinus sylvestris, in order to determine the extent of regeneration capacity in this species under drought. Seeds were collected from different populations (provenances) that, along with other climatic and edaphic differences, span a gradient of water availability: from wet (Scotland) to intermediate (Austria, Poland) to dry (Spain). In Chapter 2, the effects of osmotic stress on the initial seedling establishment stage were studied by comparing phenotypic responses across provenances. Seedling germination, early growth, osmotic stress tolerance and survival were investigated using a polyethylene glycol irrigation treatment as a proxy for rapid and severe drought. Treatment, provenance and interaction effects were found for rate of germination, final proportion of seeds germinated, seedling size, and superoxide dismutase activity (an antioxidant enzyme). Root investment was affected by both provenance and time to germination. Although there was no significant effect of provenance on survival, a trend towards increased probability of survival under osmotic stress was indicated for the southernmost (driest) as compared with the northernmost (wettest) provenance. Chapter 3 investigates the responses of older seedlings (at 10 months) to a drying down of soil moisture for 40 days. Morphological and physiological data were collected to assess intra-specific and intra-population variation in the seedling stress response under drought. A metabolomics analysis using Ultra performance Liquid chromatography followed by mass spectrometry (UPLC/MS) was carried out to investigate whether metabolic markers could be identified that are suggestive of heightened oxidative stress and whether populations in different climatic and edaphic environments show variation in metabolic activity under drought. Preliminary results suggest large intra-population variability yet clear differentiation in metabolic responses to drought over the time course of the experiment. Univariate and multivariate analyses indicated that among the most significant increases in response to drought were those involved in osmoprotective and antioxidant capabilities, including the free amino acid proline and a quercetin derivative (a flavonoid). Interestingly, provenances, either under experimental drought or not, did not show significantly different metabolite profiles, even though provenance and its interaction with drought treatment did significantly affect seedling biomass and photochemical efficiency. In Chapter 4 the effects of provenance, maternal parentage and seed weight on germination rate, final germination percentage, as well as seedling drought responses in biomass allocation and the expression of selected antioxidant genes were analysed. Seed weights were measured individually and seed weight was found to have a strong positive effect on: germination rate, seedling dry weights, and number of needles. Expression of two antioxidant enzymes increased under drought. Seed weight was strongly determined by provenance and maternal parentage as well as their interaction. However, root to shoot biomass allocation depended on provenance and maternal effects that were not mediated by seed weight effects. Principal component analysis indicated that the Spanish provenances could be characterised by a higher root to shoot ratio and stem weight. Specific leaf area was also found to be lowest for the Spanish provenances.

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No. of bitstreams: 1 andrade_acnb_dr_arafcl.pdf: 2397841 bytes, checksum: 30488d165854e1bca6eb5e7976bc1ac4 (MD5) Previous issue date: 2016-04-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este texto tem como objetivo estudar as representações da aridez, leimotiv recorrente na produção artística brasileira, no romance contemporâneo Galileia (2009), de Ronaldo Correia de Brito, no qual percebemos que a aridez exerce papel fundamental, na medida em que não é apenas tema, mas elemento estrutural que reitera – e amplia – a aridez temática. Desse modo, a aridez, metafórica, estrutural ou literal é reelaborada pelo romance em questão, no qual as figuras relacionadas à seca e ao cenário do sertão retratam relações humanas, e não um local geográfico. Portanto, nosso objetivo é especificar o modo como o código linguístico trabalha com os conceitos de seca e de aridez, tanto do ponto de vista temático quanto do estrutural, analisando a utilização dos procedimentos técnicos e estilísticos próprios na definição de uma poética da aridez, e não sobre a aridez, diferença ressaltada por Ismail Xavier em texto sobre a Estética da fome (XAVIER, 2007, p.13). Para colocar em prática nossos objetivos, faremos uma abordagem do estereótipo de sertão difundido culturalmente e elaboraremos uma descrição geral das concepções de sertão presente no romance, de acordo com os personagens de modo a abordar o modo de apreensão do espaço sertanejo pelo narrador-protagonista Adonias, para quem o sertão equivale à violência e à barbárie. Posteriormente, abordaremos justamente os exemplos de violência humana presentes na obra que justificam a visão disfórica de Adonias e originam uma Imagem poética do sertão e uma alegoria da aridez humana. Para a análise desta, estabeleceremos relações entre as descrições plásticas do cenário sertanejo às questões perenes e universais da condição humana, dando origem a uma abordagem alegórica do sertão. Por fim, analisaremos a estrutura sintática e rítmica de Galileia em sua correlação com a aridez temática e metafórica, evidente no semi-simbolismo do romance. / Este texto tem como objetivo estudar as representações da aridez, leimotiv recorrente na produção artística brasileira, no romance contemporâneo Galileia (2009), de Ronaldo Correia de Brito, no qual percebemos que a aridez exerce papel fundamental, na medida em que não é apenas tema, mas elemento estrutural que reitera – e amplia – a aridez temática. Desse modo, a aridez, metafórica, estrutural ou literal é reelaborada pelo romance em questão, no qual as figuras relacionadas à seca e ao cenário do sertão retratam relações humanas, e não um local geográfico. Portanto, nosso objetivo é especificar o modo como o código linguístico trabalha com os conceitos de seca e de aridez, This work aims to study the barrenness representation, recurrent leimotiv in Brazilian artistic productions, in Ronaldo Correia de Brito’s contemporary novel Galileia (2009), in which the dryness has a fundamental role as it is not only a theme, but also a structural element that reaffirms – and amplifies – the thematic barrenness. Thus, the novel reworks the dryness, metaphoric, structural or literal, because the images related to the drought and to the Brazilian outback scenery portrays human relations and not just a geographical place. Therefore, the objective of this dissertation is to specify how the linguistic code works with the drought and barrenness concepts, both on the thematic and on the structural perspectives, analyzing the technical and stylistic procedures usage in the definition of a dryness poetic, and not of a poetic about dryness. This difference is highlighted by Ismail Xavier in his text about the Aesthetics of Hunger (XAVIER, 2007, p.13). In order to develop these objectives, there will be an approach of the Brazilian outback stereotype culturally spread in Brazil as well as a general description of the regions concepts present in the novel. This will be done through its characters perspectives as a mean to grapple how the Brazilian outback space is apprehended by the protagonist-narrator Adonias. To whom the backlands are equivalent to barbarism and violence. Later, the work will focus on the novel examples of human violence that justify Adonias dysphoric view and creates a poetic Image of the backlands and an allegory of human barrenness. To an analysis of this allegory it is necessary to stablish connections between the plastic descriptions of the Brazilian outback scenery and the perennial questions regarding the universal human condition, which originates an allegorical approach of these backlands. Ultimately, it will be done a study of Galileia’s syntactic and rhythmic structures and its interconnection with the metaphorical and thematic barrenness that is evident in the novel semisimbolism. / CAPES: 99999.006280/2015-03

Submitted by Samara Zanetti (samarazanetti@hotmail.com) on 2016-11-09T17:14:52Z No. of bitstreams: 1 Dissertação final.pdf: 1425092 bytes, checksum: 77869aab1560a58921ae52b649d3da9d (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO null (luizaromanetto@hotmail.com) on 2016-11-16T12:20:36Z (GMT) No. of bitstreams: 1 zanetti_s_me_bot.pdf: 1425092 bytes, checksum: 77869aab1560a58921ae52b649d3da9d (MD5) / Made available in DSpace on 2016-11-16T12:20:36Z (GMT). No. of bitstreams: 1 zanetti_s_me_bot.pdf: 1425092 bytes, checksum: 77869aab1560a58921ae52b649d3da9d (MD5) Previous issue date: 2016-07-27 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O trabalho teve como objetivo avaliar as respostas morfológicas, anatômicas e nutricionais da mandioca de mesa em diferentes fases de crescimento da cultura sob condições de déficit hídrico. O experimento foi conduzido por um ano sob cultivo protegido no Faculdade de Ciências Agronômicas, Campus de Botucatu, em delineamento experimental inteiramente casualizado, com esquema fatorial 3 x 3, constituído de três fases de crescimento (90 a 180 DAP; 180 a 270 DAP e 270 a 360 DAP) da cultivar de mandioca de mesa IAC 576-70 e três tensões de água no solo ( -10, -40 e -70 kPa). As manivas-sementes com 5 a 7 gemas foram plantadas em caixas com capacidade de 500 L, sendo irrigadas diariamente, mantendo o solo na capacidade de campo até o início das fases. Aos 0, 20, 40, 60 e 80 dias após o início do déficit foram avaliados a altura de planta, o diâmetro do caule, o número de folhas por planta, a área foliar total e o índice de área foliar. As folhas da mandioca foram analisadas quanto a sua estrutura anatômica aos 150 dias após o plantio. Foram realizadas avaliações nutricionais aos 180, 270 e 360 dias após o plantio. No momento da colheita avaliou-se a massa da matéria seca da parte aérea (folhas + haste), da cepa, das raízes tuberosas e fibrosas; o comprimento e diâmetro das raízes tuberosas; o número de raízes; o índice de colheita; a razão de área foliar e a produtividade. As fases de crescimento 90 a 180 DAP e 270 a 360 dias após o plantio (DAP) foram influenciadas pelas tensões de água no solo, proporcionando reduções em todas as variáveis morfológicas e nos componentes de produção. A anatomia das folhas apresentou modificações como diminuição das espessuras do mesofilo, do parênquima lacunoso, da epiderme abaxial, e do número de elemento de vasos, e aumento da espessura e diâmetro dos elementos de vaso. Houve diminuição no teor de K nas fases de 90 a 180 e 270 a 360 DAP e aumento de P e Mg nas três fases, e Fe e Zn aos 90 a 180 DAP. A produtividade final das raízes tuberosas foi afetada pelas tensões de água no solo (-40 e -70 kPa) nas fases de 90 a 180 e 270 a 360 após o plantio. / This research aimed to evaluate the morphological, anatomical and nutritional responses of sweet cassava in different growth stages of the crop under water deficit. The experiment was carried out for a year in a greenhouse at the Faculty of Agricultural Sciences, Botucatu, in a completely randomized design in factorial scheme 3 x 3, consisting of three growth stages (90-180 DAP, 180-270 DAP and 270-360 DAP) of cultivating sweet cassava IAC 576-70 and three water tension in the soil (-10, -40 and -70 kPa). The stem cuttings with 5-7 nodes of the cultivar IAC 576-70 were planted in boxes with 500 liters capacity, keeping soil moisture at field capacity until the beginning of the phases. At 0, 20, 40, 60 and 80 days after the beginning of the deficit were measured the plant height, stem diameter, number of leaves per plant, total leaf area and leaf area index. Cassava leaves were analyzed for their anatomical structure at 150 days after planting. It were nutritional evaluations performed at 180, 270 and 360 days after planting, and at harvest evaluated the dry matter of the shoot (leaves + stem), the strain of tuberous and fibrous roots; the length and diameter of the tuberous roots; the number of roots; harvest index; the leaf area ratio and productivity. The growth phases 90 to 180 and 270 to 360 days after planting (DAP) were influenced by the water tension in the soil, providing reductions in all morphological variables and production components. The anatomy of the leaves showed changes as the decrease of the thickness of mesophyll, of the spongy parenchyma, epidermal abaxial, and of the vessels element number and increasing the thickness and diameter of vessel elements. There was a decrease in K content in phases 90180 and 270-360 DAP and increase of P and Mg in three phases, and Fe and Zn to 90-180 DAP. The final yield of tuberous roots were affected by the tensions in water (-40 to -70 kPa) in the phases 90-180 and 270-360 after planting.

Made available in DSpace on 2015-05-14T12:09:35Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 14480875 bytes, checksum: 2a243c6b865cac252087b36fb1bbd7ca (MD5) Previous issue date: 2014-03-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The Brazilian Northeast has been characterized from the beginning of its history, the stigma of periodic droughts, however most research on the topic of drought are usually developed with our gaze fixed on the physical aspects such as the severity, extent, frequency, are often neglecting the social, economic, cultural and productive aspects of the region. Given the importance of analyzing the climatic factors together with studies of existing vulnerabilities in the Brazilian semiarid region. This study aimed to show the vulnerability to drought in the municipalities of Picuí, Sumé and Sousa, respectively, located in the regions of Seridó Ocidental paraibano, Cariri Oriental paraibano and Sertão of the state of Paraíba. This was done by means of an adaptation of indicators Bhattacharya and Dass (2007), which deal with the vulnerability, and their factors of exposure, sensitivity and adaptive capacity, using data mainly from the municipalities in the year 2010 in government agencies and non-governmental, official websites on the internet and through fieldwork. It was concluded by analyzing the results of Picuí that the municipality had the highest exposure, with an index of 0.39043 and worse performance sensitivity, with the index of 0.2515. Regarding the indicator Adaptive Capacity of the municipality Sume was the one that stood out negatively, getting the index of 0.3155. In general terms the municipality of Picuí showed the greatest vulnerability (0.3467), followed by the municipality of Sume (0.2973) and the municipality of Sousa (0.2876) Indicators of Exposure, Sensitivity and Adaptive Capacity is shown to be useful tools for the analysis of the intrinsic characteristics of drought, population characteristics, production activities and the way that they are practiced. About Vulnerability Index, it was set up as a suitable for the study of holistic risk management to environmental disasters instrument that can be used for the formulation of public policies for managers and decision makers and can assist the development of plans local preparedness, mitigation and coexistence of drought weather / O Nordeste brasileiro tem sido caracterizado, desde o início de sua história, pelo estigma das secas periódicas. Entretanto, a maioria das pesquisas sobre a temática da seca normalmente são desenvolvidas com o olhar voltado para os aspectos físicos como sua severidade, extensão, periodicidade, negligenciando muitas vezes os aspectos sociais, econômicos, culturais e produtivos da região. Tendo em vista a importância de se analisar os fatores climáticos conjuntamente com estudos das vulnerabilidades existentes na região semiárida brasileira. Este trabalho buscou evidenciar as vulnerabilidades à seca nos municípios de Picuí, Sumé e Sousa, respectivamente situados nas microrregiões do Seridó Oriental, Cariri Ocidental paraibano e Sertão do estado da Paraíba. Isso foi feito por meio de uma adaptação dos indicadores de Bhattacharya e Dass (2007), que versam sobre a vulnerabilidade, e seus fatores de exposição, sensibilidade e capacidade adaptativa, utilizando-se dados dos municípios principalmente do ano de 2010, em órgãos governamentais e não governamentais, na internet em sites oficiais e por meio de trabalhos de campo. Concluiu-se por meio da análise dos resultados que o município de Picuí obteve a maior exposição, com um índice de 0,39043 e pior desempenho à sensibilidade, com o índice de 0,2515. Já em relação ao indicador de Capacidade Adaptativa o município de Sumé foi o que mais se destacou negativamente, obtendo o índice de 0,3155. Em termos gerais o município de Picuí foi o que apresentou maior vulnerabilidade (0,3467), seguido do município de Sumé (0,2973) e do município de Sousa (0,2876). Os Indicadores de Exposição, Sensibilidade e Capacidade Adaptativa mostraram-se como ferramentas úteis para a análise das características intrínsecas da seca, características das populações, das atividades produtivas e o modo de como elas são praticadas. Sobre o Índice de Vulnerabilidade, este se configurou como um instrumento adequado para o estudo holístico da gestão de riscos a desastres socioambientais, que pode ser utilizado para a formulação de políticas públicas por parte dos gestores e tomadores de decisão e podem auxiliar a elaboração de planos locais de preparação, convivência e mitigação das intempéries da seca

Orientadora: Sonia Marli Zingaretti Di Mauro / Banca: Maria Inês Tiraboschi Ferro / Banca: Renê de Oliveira Beleboni / Resumo: A cultura da cana-de-açúcar é de grande importância econômica nas regiões tropicais e subtropicais, especialmente para alguns países da América, como o Brasil, que é atualmente o maior produtor mundial. Estresses abióticos, como a seca, podem reduzir os rendimentos das lavouras. Sendo assim, a identificação e a compreensão dos mecanismos de tolerância à seca são fundamentais no desenvolvimento de novas cultivares comerciais mais tolerantes ao déficit hídrico. O objetivo deste trabalho foi identificar, através da técnica de macroarranjos de cDNA, o perfil de expressão de genes pertencentes a diferentes vias metabólicas em folhas de duas cultivares de cana-de-açúcar (Saccharum spp), uma tolerante ao estresse por déficit hídrico (SP83-2847) e outra sensível (SP90-1638) submetidas a dois períodos de restrição no fornecimento de água, ocasionando um estresse por déficit hídrico leve (T1) e severo (T2). Por meio das análises dos resultados foi possível identificar, na cultivar tolerante, a indução de ESTs (etiquetas de seqüências expressas) com similaridade a genes de enzimas de síntese de osmoprotetores, tais como prolina, hidroxiprolina e GABA (ácido g-aminobutírico); de hormônios vegetais como o ácido abscísico (ABA) e o ácido jasmônico (JA) e repressão de ESTs similares aos genes das enzimas de biossíntese de amido, de glicina betaína e de algumas enzimas do sistema de defesa antioxidante. Ao passo que, na cultivar sensível foram induzidas ESTs similares aos genes de enzimas de síntese dos osmoprotetores trealose e glicina betaína; do sistema de defesa antioxidante e reprimidas ESTs com similaridade a genes das enzimas de síntese de prolina, hidroxiprolina e GABA e envolvidas na biossíntese de ABA e de jasmonatos. Em ambas as cultivares, ESTs similares a genes de diferentes enzimas fotossintéticas foram reprimidas. / Abstract: Sugarcane crop is of large economic importance in the tropical and subtropical regions, especially in some countries of Central and South America as Brazil, which is actually the major worldwide producer. Abiotic stress, such as drought, can reduce yield of the farmings. Thus, identification and understanding of the drought tolerance mechanisms is crucial to the development of new commercials cultivars more tolerant to water deficit. The aim of this study was to identify, using cDNA macroarrays technique, expression profile of genes involved in distinct metabolic pathways in leaves of two sugarcane (Saccharum spp) cultivars, one water stress tolerant (SP83-2847) and another water stress sensitive (SP90-1638) which were submitted to periods of withhold watering occasioning a mild (T1) and severe (T2) water deficit stress. Through the analysis of the results, it was identified in the tolerant cultivar up-regulated ESTs similar to genes of enzymes involved in the synthesis of osmoprotectants, such as proline, hydroxyproline, GABA (g-amino butyric acid), of synthesis of plant hormones as abscisic acid (ABA) and jasmonic acid (JA); and down-regulated ESTs similar to genes of enzymes of the biosynthesis of starch, glycine betaine and of some enzymes involved antioxidant defense system. In the other hand, ESTs similar to genes of enzymes involved in the biosynthesis of the osmoprotectants as trehalose and glycine betaine and enzymes from the antioxidant defense system were induced as well as were down-regulated ESTs similar to genes of enzymes of synthesis of proline, hydroxyproline and GABA and involved in biosynthesis of ABA and jasmonates, for the sensitive cultivar. In both cultivars, ESTs with similarity to genes of different photosynthetic enzymes were repressed. / Mestre