Made available in DSpace on 2015-03-26T13:50:02Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1247950 bytes, checksum: 0840510708636790c84fc24445425dfd (MD5) Previous issue date: 2010-02-24 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objective of this work was to evaluate the behavior of leaf temperature and transpiration of sugarcane under different matric and meteorological conditions to estimate a crop water stress index (IEHC), which can be applied in irrigation management and estimates of productivity. Because of the need to apply water stress to plants, the experiment was conducted in a greenhouse, belonging to the Agricultural Engineering Department at the Federal University of Viçosa, Viçosa, MG, Brazil. Bud chips of sugarcane (cv. RB867515) were planted on May 6, 2009, in plastic pots with a capacity of 10 liters, which were filled with a commercial substrate. In total, 192 plants were grown for 6 months within the greenhouse, but only a portion was used in measurements. To evaluate the effect of water availability on leaf temperature and transpiration, under different meteorological conditions, three classes of water tension (&#936;) were maintained in the substrate: no water stress (&#936; < 0,5 bar), moderate (4,0 < &#936; < 6,0) and severe (&#936; > 11,0 bars) water stress. A meteorological data acquisition system was implemented for measuring global solar radiation (Rg), air velocity (U), air relative humidity (UR), air temperature (tar) and transpiration of three individual plants randomly chosen. In addition, leaf temperature (tc) was obtained by positioning an infrared thermometer at three different points of each plant used in the transpiration measurements. Based on the measurements obtained without water stress, it was found that the leaf temperature followed fluctuations of solar radiation caused by conditions of partly cloudy sky. In general, tc was lower than tar under no water stress conditions, with maximum difference of 6ºC. The effect of water stress on leaf temperature and transpiration was determined from the suspension of irrigation, by performing three measurement campaigns, initiated at 122, 150 and 181 days after planting, with two days intervals, until the water tension in the substrate reached 15 bars. Under severe water stress conditions, tc became 6.8°C higher than t ar. By using regression analysis, relations were established between the differential tc-tar and the variables global solar radiation (Rg) and air water vapor pressure deficit (DPVar), in order to determine the parameters necessary for obtaining the IEHC. / The objective of this work was to evaluate the behavior of leaf temperature and transpiration of sugarcane under different matric and meteorological conditions to estimate a crop water stress index (IEHC), which can be applied in irrigation management and estimates of productivity. Because of the need to apply water stress to plants, the experiment was conducted in a greenhouse, belonging to the Agricultural Engineering Department at the Federal University of Viçosa, Viçosa, MG, Brazil. Bud chips of sugarcane (cv. RB867515) were planted on May 6, 2009, in plastic pots with a capacity of 10 liters, which were filled with a commercial substrate. In total, 192 plants were grown for 6 months within the greenhouse, but only a portion was used in measurements. To evaluate the effect of water availability on leaf temperature and transpiration, under different meteorological conditions, three classes of water tension (&#936;) were maintained in the substrate: no water stress (&#936; < 0,5 bar), moderate (4,0 < &#936; < 6,0) and severe (&#936; > 11,0 bars) water stress. A meteorological data acquisition system was implemented for measuring global solar radiation (Rg), air velocity (U), air relative humidity (UR), air temperature (tar) and transpiration of three individual plants randomly chosen. In addition, leaf temperature (tc) was obtained by positioning an infrared thermometer at three different points of each plant used in the transpiration measurements. Based on the measurements obtained without water stress, it was found that the leaf temperature followed fluctuations of solar radiation caused by conditions of partly cloudy sky. In general, tc was lower than tar under no water stress conditions, with maximum difference of 6ºC. The effect of water stress on leaf temperature and transpiration was determined from the suspension of irrigation, by performing three measurement campaigns, initiated at 122, 150 and 181 days after planting, with two days intervals, until the water tension in the substrate reached 15 bars. Under severe water stress conditions, tc became 6.8°C higher than t ar. By using regression analysis, relations were established between the differential tc-tar and the variables global solar radiation (Rg) and air water vapor pressure deficit (DPVar), in order to determine the parameters necessary for obtaining the IEHC

Submitted by SUZANA TARGANSKI SAJOVIC PEREIRA null (suzana_tsp@hotmail.com) on 2016-08-24T18:34:25Z No. of bitstreams: 1 Dissertação_Suzana_Targanski_Sajovic_Pereira.pdf: 2840184 bytes, checksum: e7bd2eed88ab9bd548d7561bb3b326d6 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-08-26T13:27:22Z (GMT) No. of bitstreams: 1 pereira_sts_me_jabo.pdf: 2840184 bytes, checksum: e7bd2eed88ab9bd548d7561bb3b326d6 (MD5) / Made available in DSpace on 2016-08-26T13:27:22Z (GMT). No. of bitstreams: 1 pereira_sts_me_jabo.pdf: 2840184 bytes, checksum: e7bd2eed88ab9bd548d7561bb3b326d6 (MD5) Previous issue date: 2016-07-28 / O objetivo deste trabalho foi verificar a influência da temperatura, da luz, do substrato, das formas de semeadura, do estresse salino e hídrico na germinação da gramínea Axonopus affinis. Foram quatro experimentos, todos conduzidos em câmara de germinação, onde as condições de temperatura, umidade e fotoperíodo foram controladas; o delineamento experimental utilizado foi inteiramente casualizado e utilizou-se 100 sementes por parcela. Para o estudo da temperatura e da luz (experimento 1), os tratamentos foram arranjados em esquema fatorial 6 x 2, composto de seis condições de temperatura (constante de 20, 25, 30 e 35 ºC e alternadas de 20-30 ºC e 20-35 ºC) e duas condições de luminosidade (―claro‖: 8 horas de luz e 16 horas de escuro e ―escuro‖: 24 h na ausência de luz) e quatro repetições. Para o estudo de substrato e forma de semeadura (experimento 2) foram quatro tratamentos (sobre papel, entre papel, sobre areia e entre areia) e cinco repetições. Para o estudo do estresse salino (experimento 3) foram cinco tratamentos (concentrações de NaCl: 0, 25, 50, 75 e 100 mM) e quatro repetições. Para o estudo do estresse hídrico e formas de semeadura (experimento 4), os tratamentos foram distribuídos em esquema fatorial 3 x 2 onde foram testados três níveis de capacidade de retenção de água (50, 75 e 100%) e duas formas de semeadura (sobre areia e entre areia) e quatro repetições. Avaliou-se porcentagem de germinação e Índice de Velocidade de Germinação. Concluiu-se que a germinação de sementes foi mais efetiva em temperaturas alternadas de 20-30 ºC e 20-35 ºC sob condição de luz e nos substratos sobre papel, entre papel e sobre areia; a concentração de NaCl não afetou a porcentagem de germinação, porém, o aumento da concentração diminuiu gradativamente a velocidade de germinação; maior porcentagem e velocidade de germinação ocorreu quando as sementes foram colocadas sobre areia, mantida com 100% da capacidade de retenção de água. / This work aim was verify the temperature, light, substrate, ways of sowing, and salt and hydric stress influence into the Axonopus affinis germination. All the four trials were carried out in a germination chamber under temperature, humidity, and photoperiod controlled conditions. The experimental design used was the completely randomized one, with 100 seeds in each plot. To study the temperature and light (experiment 1), the trials were arranged in a factorial scheme 6x2, with six temperature conditions (constant temperatures of 20, 25, 30 and 35 °C and alternate temperatures of 20-30 °C and 20-25 °C) and two lightning conditions (light: 8 hours of light and 16 hours of dark and "dark": 24 h in the dark) and four replications. To the substrate and sowing trial (experiment 2) we used four treatments (on paper, between paper, on sand, and between sand) with five replications. To the salt stress trial (experiment 3) we used five treatments (NaCl concentrations: 0, 25, 50, 75, and 100 mM) with four replications. To the hydric stress trial the treatments were arranged in a 3x2 factorial scheme (experiment 4) where we tested three levels of water retention capacity (50, 75, and 100%) and two ways of sowing (on sand and between sand) and four replications. We evaluated the germination percentage and Germination Time Index. We could conclude that the seed germination was more effective when the temperature was alternated of 20-30 °C and 20-35 °C, under light condition, and on a paper substrate, between papers and on the sand. The NaCl concentration did not affect the germination percentage. However, the higher was the NaCl concentration, the slower was the germination. A faster and higher germination occurred when seeds were on the sand kept at 100% of water retention capacity.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The increasing demand for biofuels has provided significant increases in the areas of sugar cane in Brazil and in recent decades,and long periods of drought have limited the production of this species. This study aimed to evaluate the performance of cultivars RB 85-5536 and RB 93-509 of cane sugar on water restriction during the first stages of development. Experiment was carried out in the greenhouse of the Department of Agronomic Engineering at UFS in randomized blocks in factorial2 x 4, two cultivars (RB 85-5536 and RB 93-509) and four levels of water in the soil based on predefined at field capacity (100% Cc, 80% Cc, 60% Cc and 40% Cc), with four replications, each replicate consisting of a plant. Were evaluated the initial fluorescence emission (F0), maximum fluorescence (Fm), the quantum yield of photosystem (Fv/Fm) and fluorescence transient OJIP, indices of photosynthetic pigments and proline contents determined in leaves determined +1. The measurements of emission of fluorescence were performed during the period of seven days every two days, from 10 to 12 am, with the aid of fluorometer (OS-30P) and clips fixed on the central portion of the leaf, the contents of pigments were determined in the same period with the aidofaportable chlorophyllmeter (Clorofilog CFL 1030) whereas the proline content in the end of the experiment. The fluorescence emission levels and rates of photosynthetic pigments decreased with the increase of water restriction in both cultivars. The cultivar RB 93-509 has accumulated higher proline contentat the level of stress 60% of Cc. With the increase of stress severe by water restriction occurs a reduction in total levels of chlorophyll fluorescence and photosynthetic pigment contents from the seventh day of stress in both varieties of sugar cane. The cultivar RB 93-509 presents greater sensitivity to water stress than the cultivar RB 85-5536. / A crescente demanda por biocombustíveis tem proporcionado aumentos significativos das áreas de cana-de-açúcar no Brasil e nas últimas décadas os períodos prolongados de seca têm limitado a produção dessa espécie. Esse trabalho teve por objetivo avaliar o comportamento das cultivares RB 85-5536 e RB 93-509 de cana-deaçúcar quanto à restrição hídrica visando à seleção precoce. O experimento foi conduzido em casa de vegetação do Departamento de Engenharia Agronômica da UFS em delineamento experimental de blocos ao acaso em esquema fatorial 2 x 4, duas cultivares (RB 85- 5536 e RB 93-509) e quatros níveis de água no solo predefinidos com base na capacidade de campo (100% Cc, 80% Cc, 60% Cc e 40% Cc), com quatro repetições, sendo cada repetição constituída por uma planta. Foram avaliadas a emissão de fluorescência inicial (F0), fluorescência máxima (Fm), rendimento quântico do fotossistema (Fv/Fm) e fluorescência transiente OJIP,índices de pigmentos fotossintetizantes e teores de prolina determinados nas folhas +1. As medições da emissão de fluorescência foram realizadas durante o período de sete dias, a cada dois dias, entre 10 e 12 h da manhã, com auxílio de fluorímetro (OS-30P) e clipes fixados na porção mediana do limbo foliar, os índices de pigmentos foram determinados no mesmo período com auxílio de um medidor portátil de clorofila (Clorofilog CFL 1030) enquanto que o teor de prolina no final do experimento.Os níveis de emissão de fluorescência e os índices de pigmentos fotossintéticos reduziram com o aumento da restrição hídrica em ambas cultivar. A cultivar RB 93-509 acumulou maior teor de prolina ao nível de estresse de 60% da Cc. Com o aumento do estresse severo de restrição hídrica ocorre redução total nos níveis de fluorescência da clorofila e índices de pigmentos fotossintéticos ao sétimo dia de estresse em ambas cultivar de cana-de-açúcar. A cultivar RB 93-509 apresenta maior sensibilidade ao estresse hídrico que a cultivar RB 85-5536.

Orientador: Rinaldo César de Paula / Banca: Susi Meire Maximino Leite / Banca: Magali Ribeiro da Silva / Banca: Maria Inês Tiraboschi Ferro / Banca: Arlindo Leal Boiça Junior / Resumo: O objetivo deste trabalho foi avaliar o comportamento de cinco híbridos de Eucalyptus grandis x Eucalyptus urophylla (H1, H2, H3, H4 e H5) submetidos a quatro regimes de irrigação (RI1 - irrigação diária; RI2 - irrigação a cada dois dias; RI4 - irrigação a cada quatro dias e RI6 - irrigação a cada seis dias). O experimento foi implantado em casa de vegetação no delineamento de blocos casualizados no esquema fatorial 5 x 4 (cinco híbridos e quatro regimes de irrigação), com quatro repetições, usando como substrato 10,5 Kg de um Neossolo Quartzarênico. Foram avaliadas características de crescimento como: incremento relativo em diâmetro de coleto, em altura, em número de folhas, em área foliar, em massa seca de folhas, de caule, de raízes e total e razão raiz- parte aérea; fisiológicas como: taxa de assimilação líquida, transpiração, condutância estomática, concentração interna de CO2, potencial hídrico foliar, conteúdo relativo de água, eficiência fotoquímica e índice de conteúdo de clorofila total; e bioquímicas como: teores foliares de prolina livre e de glicina betaína. As avaliações fisiológicas foram realizadas em sete ciclos; mas, para fins de análise estatística foram consideradas as médias dos ciclos. Essas características também foram avaliadas 48 h após a irrigação de todos os tratamentos, formando-se assim dois grupos de características: sob estresse (no momento em que as plantas estariam submetidas à maior deficiência hídrica) e sob recuperação (após a irrigação de todas as plantas do experimento). As características biométricas e fisiológicas apresentaram menores valores com a redução da disponibilidade hídrica, independentemente dos híbridos de Eucalyptus grandis x Eucalyptus urophylla. As alterações na área foliar, na massa de matéria seca de caule e na condutância estomática são boas... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this work was to evaluate the behavior of five Eucalyptus grandis x Eucalyptus urophylla hybrids (H1, H2, H3, H4 and H5) submitted to four irrigation regimes (RI1 - daily; RI2 - every two days; RI4 - every four days; RI6 - every six days). The experiment was carried out in a greenhouse, in a randomized block design with a factorial scheme 5 x 4 (five hybrids and four irrigation regimes), with four replications, using 10.5 kg of Neossol Quartzarenic soil. It was evaluated the biometric traits: relative increment at collar diameter, height, leaves number, leaf area, dry mater of the leaves, of the stem, of roots and total mater, root-shoot ratio; physiological traits: net photosynthesis, transpiration, stomatal conductance, leaf water potential, relative water contents, photochemistry efficiency and index of chlorophyll contents; and biochemical traits: foliar contents of free proline and glycine betaine. The physiological evaluations were performed during seven cycles, but for statistics analysis they were considered the means from ones. The physiological traits were also evaluated 48 h after irrigation of every irrigation regimes. Two groups of values were created: under stress (in the plants were submitted to water stress) and under recovery (after irrigation). Biometric and physiological trait decreased by reduced water availability, regardless of hybrids of Eucalyptus grandis x Eucalyptus urophylla. Changes in leaf area, dry matter of stem and stomatal conductance are good indicators of water stress. The higher proline accumulation in leaves due to reduced water availability is associated with the water stress but not to tolerance of hybrids to drought. The glycine betaine levels are not related to tolerance of hybrids or to the conditions of the soil water availability. The hybrid H3 is more tolerant and H5 is the most sensitive to reduced water availability in soil / Doutor

Orientadora: Sonia Marli Zingaretti / Banca: Janete Apparecida Desidério Sena / Banca: Miriam Vergínia Lourenço / Resumo: O acúmulo de um açúcar com propriedades osmoprotetoras, a trealose (a-D-glicopiranosil-[1,1]-a-D-glicopiranose), é muito comum em microorganismos, invertebrados e em algumas plantas superiores. A trealose é sintetizada a partir da UDP-glicose e glicose-6-fosfato num processo de dois passos onde atuam duas enzimas principais, trealose-6-fosfato sintase ou TPS e trealose-6-fosfato fosfatase ou TPP. A TPS e o seu produto a trealose-6-fosfato (T6P) são prováveis sinalizadores para o metabolismo de carboidratos, contribuindo para o aumento da tolerância de plantas ao estresse hídrico.Este trabalho analisou a expressão in si/ico a partir de 110 transcritos de TPS isolados de bibliotecas de tecidos e tratamentos distintos provenientes do projeto SUCEST. Dois destes genes relacionados a TPS, o STPS 1 e o STPS2 apresentaram expressão diferencial em estudos anteriores em cana-de-açúcar sob estresse hídrico. Em plantas as TPSs foram divididas em duas subfamílias (classe I e 11). Em cana-de-açúcar a STPS1 pertence aos genes de classe I, pois, não possuem domínio fosfatase (TPP) ativo, enquanto que a STPS2 possui domínios TPP ativos (classe 11) determinados pela presença de fosfatase "boxes". Análises de expressão, baseadas no método de RT-PCR semiquantitativo, foram realizadas com os genes STPS1 e STPS2 em plantas sensíveis e tolerantes ao déficit hídrico nos períodos iniciais de estresse (24h, 72h e 120h). Os resultados mostram que o gene STPS1 é induzido em cultivares tolerantes de cana-de-açúcar sob estresse e reprimido em plantas sensíveis. Já o gene STPS2 não apresenta variações consideráveis nos níveis de expressão para os mesmos tratamentos. / Abstract: The accumulation of a sugar with osmoprotectant properties, the trehalose (a-D-glucopyranosyl-[1,1]-a-D-glucopyranoside), is very common in microorganisms, invertebrates and in some higher plants. Trehalose is synthesized from the UDP-glucose and glucose-6-phosphate in a process of two steps where two main enzymes act, trehalose-6-phosphate synthase or TPS and trehalose-6¬phosphate phosphatase or TPP. The TPS and its product the trehalose-6-phosphate (T6P) are probable signaling molecules in the carbohydrate metabolism, contributing to enhance the plants tolerance to water stress. This work analyzed the in silico expression from 110 transcripts of TPS acquired from different libraries of tissues and treatments proceeding from the SUCEST project. The result showed that the TPS gene is present in ali tissues of the plant. Two of these TPS genes, the STPS1 and the STPS2 showed differential expression in previous studies in sugarcane under water stress. In plants the TPSs are divided in two subfamilies (class I and 11). In sugarcane the STPS 1 belongs to the class I genes, therefore, it does not have an active phosphatase (TPP) domain, whereas, the STPS2 has an active TPP domain (classroom 11) determined by the presence of phosphatase boxes. Expression analyses, based in the semi-quantitative method of the reverse transcription¬polymerase chain reaction (RT-PCR), were performed with the STPS1 and STPS2 genes in water-stress susceptible and tolerant sugarcane cultivars in the initial periods of stress (24h, 72h and 120h). The results show that the STPS1 gene is up¬regulated in the tolerant cultivar under stress and down-regulated in susceptible plants.The STPS2 gene does not show considerable variations in the expression levels under the same treatments. / Mestre

Orientador: Durvalina Maria Mathias dos Santos / Banca: Márcia Justino Rossini Mutton / Banca: João Atílio Jorge / Resumo: No presente estudo, verificou-se o acúmulo da trealose e da prolina livre e o crescimento inicial de duas cultivares de cana-de-açúcar, IAC91-2195 e IAC91-5155, sensível e tolerante ao estresse hídrico, respectivamente. Inicialmente, as mudas foram cultivadas sem qualquer restrição hídrica. Após 40 dias, foram transferidas para vasos com três níveis de disponibilidade hídrica do solo (DHS): 55% (sem estresse), 40% (estresse moderado) e 25% (estresse severo), mantidos pelo método das pesagens durante 30 e 60 dias. O delineamento experimental foi em blocos ao acaso, com quatro repetições, em arranjo fatorial 2x3x2 (cultivares x deficiência hídrica x épocas de crescimento). O experimento foi conduzido em casa de vegetação climatizada (29ºC e 75% UR). A cultivar IAC91-5155 apresentou maior acúmulo de trealose e de prolina livre nos menores níveis de disponibilidade hídrica do solo, indicando tolerância às condições de estresse hídrico. Aos 30 dias, sob estresse hídrico, houve maior acúmulo de prolina livre apenas na cv. IAC91-5155. Os osmoprotetores, trealose e prolina livre, podem ser indicados como marcadores bioquímico-fisiológicos de tolerância ao estresse hídrico somente para a cv. IAC91-5155. A cv. IAC91-5155 pode ser considerada mais tolerante ao estresse hídrico que a cv. IAC91-2195. / Abstract: In this work, the accumulation of trehalose and free proline and the initial growth were measured in two sugarcane cultivars, IAC91-2591 and IAC91-5155, sensitive and stress tolerant, respectively. Buds, after 40 days old cultivated in soil with no water restriction when were transferred to pots and submitted to three soil water levels: 55% (no stress), 40% (moderate stress) and 25% (severe stress). The experiment was carried out in greenhouse (29ºC and 75% RH). The Weighing Method was used to control the soil water levels for 30 and 60 days. The experimental design was randomized blocks with four replicates in 2x3x2 factorial arrangement (cultivars, water deficit and periods of growth). The cultivar IAC91-5155 showed higher accumulation of the trehalose and free proline under water deficiency. The accumulation of the proline was higher in IAC91-5155 cultivar at 30 days under soil water levels. Trehalose and free proline could only be considered as biochemical-physiological markers to soil water deficits in cultivar IAC91-5155. The cultivar IAC91-5155 may be more tolerant to water stress than IAC91-2195. / Mestre

Orientador: Rinaldo César de Paula / Banca: Pedro Luis da Costa Aguiar Alves / Banca: Susi Meire Maximino Leite / Resumo: O presente trabalho objetivou avaliar o desempenho de 40 clones de eucalipto submetidos a dois regimes de irrigação em casa de vegetação: RI1 - plantas sem restrição hídrica e RI2 - plantas cuja irrigação foi suspensa até o aparecimento de sintomas iniciais de deficiência hídrica (murcha). As plantas do regime RI2, ao final do ciclo de suspensão da irrigação, foram irrigadas de forma que o solo atingisse 21% de água (v/v), o que correspondeu a aproximadamente a 60% da capacidade máxima de retenção de água pelo solo; após isto, a irrigação foi novamente suspensa, repetindo-se o ciclo. No decorrer do experimento, foram conduzidos seis ciclos de estresse hídrico. No início e ao final do experimento, foram avaliados o diâmetro do coleto, a altura, o número de folhas, a área foliar e a massa de matéria seca de folhas, caule e raízes e da parte aérea, bem como a relação raiz-parte aérea e a massa por área de folhas. Nos momentos de máximo estresse hídrico, foram avaliadas as seguintes características: teor relativo de clorofila total (UR), medida da eficiência quântica do fotossistema II (Fv/Fm), taxa de assimilação líquida (A), condutância estomática (gs), taxa de transpiração (E), eficiência intrínseca do uso da água (EUAintr=A/E) e eficiência instantânea do uso da água (EUAinst=A/gs). Ao final do experimento foi determinado o potencial hídrico foliar (Ψf) e o conteúdo relativo de água (CRA). O experimento foi estabelecido no delineamento de blocos casualizados, no esquema fatorial 40 x 2 (40 clones e 2 regimes de irrigação), com quatro repetições. Os dados foram submetidos à análise de variância (teste F) e as médias comparadas pelo teste de Scott-Knott a 5%. Procedeu-se ainda ao estudo da divergência genética entre os clones, a partir da distância Euclidiana média, aplicando-se o algoritmo de otimização de Tocher. Observou-se... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This work aiming to evaluate the performance of 40 clones of eucalyptus submitted to two irrigation regimes in a greenhouse: RI1 - plants without water restriction and RI2 - plants whose irrigation was suspended until the appearance of symptoms of water deficit. Plants of the RI2 regime at the end the cycle of irrigation suspension were irrigated until 60% of capacity retention water, after which irrigation was suspended again repeating the cycle. During the experiment were conducted six cycles of drought stress. At the beginning and end of the experiment, were analyzed the collar diameter, height, leaf number, leaf area and dry weight of leaves, stems, roots and shoots and ratio root-shoot and mass by leaf area. In the moment of maximum water stress were evaluated the following traits: the total chlorophyll content (UR), the quantum efficiency of photosystem II (Fv/Fm), rate of liquid assimilation (A), stomatal conductance (gs), transpiration (E), intrinsic water use efficiency (WUEintr = A/E) and instantaneous water use efficiency (WUEinst = A/gs). At the end of the experiment was determined the leaf water potential (Ψf) and relative water content (RWC). The experiment was established in randomized blocks desigin in factorial scheme 40 x 2 (40 clones and two irrigation regimes), with four replications. The data were submitted to analysis of variance (F test) and the means compared by Scott-Knott test at 5%. The genetic divergence was obtained by Euclidean distance, applying the techniques of clustering by the Tocher optimization algorithm. All clones showed reductions in the values of traits under water limitation (RI2). Some clones showed better adjustment to the physiological and biometric traits under RI2. The clones 11, 16, 24 and 31 are more tolerant and the clones 1, 4, 5, 17 and 19 are the most sensitive to water deficiency, and are recommended for news studies of tolerance... (Complete abstract click electronic access below) / Mestre

Resumo: As aquaporinas (AQP) são proteínas canais de água importantes e correlacionados a tolerância de plantas à seca. A busca por sequências homólogas de AQP junto ao banco de dados SUCEST (sugarcane EST Project) identificou 33 SAS (sugarcane assembed sequences), pertencentes a quatro classes, sendo a PIP (proteína intrínseca da membrana plasmática) subdividida em PIP1 e PIP2. A análise de expressão gênica para ScPIP2;1 em ensaios de estresse ao déficit hídrico in vitro e a campo demonstrou diferentes padrões de expressão para os genótipos IACSP94-2094 (tolerante) e IACSP97-7065 (sensível). No ensaio in vitro foi identificado no genótipo tolerante maior expressão em 48h após o déficit hídrico pelo tratamento com polietilenoglicol 15% (PEG). No sensível a expressão aumentou gradativamente sendo em 72h e 120h o maior nível de expressão após o déficit hídrico. O genótipo sensível apresentou elevado número de transcritos para ScPIP2;1. Os resultados demonstram que o genótipo sensível tanto a campo como in vitro expressa mais ScPIP2;1 que o tolerante, sendo este gene um candidato importante para o melhoramento genético de cana na identificação de genótipos superiores em relação à seca / Abstract: Aquaporins (AQP) are important water channels proteins correlated to drought tolerance in plants. The search for sequences homologous to AQPs in SUCEST (sugarcane EST Project) database identified 33 SAS (sugarcane assembled sequences) from four classes, one of them being PIP (plasma membrane intrinsic protein), which is divided into two subgroups, PIP1 and PIP2. The analysis of gene expression for ScPIP2;1 in vitro and in field trails showed different expression patterns in genotypes IACSP94-2094 (tolerant) and IACSP97-7065 (sensitive). For the in vitro experiment, increased expression of ScPIP2;1 was observed for the tolerant genotype after 48 hours exposure to 15% polyethylene glycol (PEG) . The ScPIP2;1 transcript level for the sensitive genotype showed gradual increases after 72 and 120h exposure to PEG. The results indicate a higher expression of ScPIP2;1 in the sensitive genotype compared to the tolerant for both field and in vitro experiments, and this gene seems to be an important candidate for the identification of superior genotypes for sugarcane genetic breeding aiming drought tolerance / Orientador: Dilermando Perecin / Coorientador: Silvana Aparecida Creste Dias de Souza / Banca: Janete Apparecida Desiderio / Banca: Michael dos Santos Brito / Mestre

Cette thèse s'inscrit dans le cadre du projet Digiplante au laboratoire MAS de l’École Centrale Paris, en collaboration avec l'unité de recherche G-eau au sein de l'IRSTEA. Dans un contexte de raréfaction de la ressource en eau, il est important de mieux valoriser l'usage de l'eau dans la production agricole. Pour la conception d'outils d'aide à la décision pour les agriculteurs ou les gestionnaires agricoles, il est nécessaire de développer une démarche quantitative permettant de décrire l'interaction de la ressource en eau avec la production végétale. Dans ce contexte, l'objectif de cette thèse multidisciplinaire est de proposer une méthodologie basée sur la modélisation de l'interaction plante-sol-atmosphère par couplage de modèles et sur le contrôle optimal pour gérer les stratégies d'irrigation. La première contribution de cette thèse consiste en le développement et l'étude de modèles couplés plante-sol, à différentes échelles. A titre de comparaison avec le modèle Pilote qui simule le rendement en se basant sur l'indice de récolte et la description empirique de l'indice foliaire LAI, on a proposé deux autres niveaux de modélisation pour la partie plante, ainsi que leur couplages avec le module sol de Pilote. D'une part, on a introduit un modèle par compartiments qui permet à la fois une gestion plus fine de l'allocation et une meilleure adaptation aux données expérimentales. D'autre part, le couplage a aussi été effectué avec le modèle GreenLab qui décrit la croissance architecturale de la plante. Ceci a nécessité le développement d'une version continue de GreenLab qui facilite en particulier l'intégration de l'effet du stress hydrique. Un jeu de données expérimentales a permis la paramétrisation de ces modèles, sous différents régimes d'irrigation et donc différents niveaux de stress hydrique. La deuxième contribution majeure a été le développement d'un cadre méthodologique pour le contrôle optimal des apports d'eau, dans le cas déterministe et le cas stochastique. La résolution proposée est basée sur la programmation dynamique qui permet de traiter différentes formulations du critère à optimiser, sans contraintes ou avec contraintes (par exemple logistiques ou réglementaires, comme les quotas d'irrigation). Une version itérative de l'algorithme a également été proposée afin d'améliorer la performance de la résolution numérique, mais également afin de pouvoir gérer les systèmes dynamiques à retards (qui peuvent apparaître pour certaines formulations du processus de sénescence dans les modèles de croissance). Notre méthodologie générique a pu être appliquée pour des problématiques concrètes, et permet d'envisager l'élaboration d'outils d'aide à la décision en agriculture afin de gérer les ressources en eau de façon plus efficace. / This thesis is part of the project Digiplante in the MAS laboratory of Ecole Centrale Paris, in collaboration with the research unit G-water in the IRSTEA. In a context of scarcity of water resources, it is important to better promote the use of water in agricultural production. When designing decision support tools for farmers or farm managers, it is necessary to develop a quantitative approach to describe the interaction of water resources with crop production. In this context, the objective of this thesis is to propose a multidisciplinary methodology based on modeling the soilplant- atmosphere interaction with coupled models and on the strategy optimization for managing irrigation. The first contribution of this thesis is the development and study of plant-soil coupled models at different scales. In comparison with the Pilote model that simulates the crop yield based on the harvest index and the empirical description of the leaf area index LAI, we proposed two other levels of modeling for the plant part and their coupling with the soil module of Pilote. On the one hand, we have introduced a compartment model which allows both a finer management of the allocation and better adaptation to the experimental data. On the other hand, the coupling was also carried out with the GreenLab model which describes the architectural growth of the plant. This has necessitated the development of a continuous version of GreenLab which facilitates in particular the integration of the effect of water stress. A set of experimental data has allowed the parametrization of these models under different irrigation regimes and thus different levels of water stress. The second major contribution was the development of a methodological framework for the optimal control of water supplies in both deterministic and stochastic case. The proposed resolution is based on dynamic programming that can handle different optimization criterion either without or under constraints (for example regulatory or logistical constraints, such as irrigation quotas). An iterative version of the dynamic programming algorithm has also been proposed to improve the performance of the numerical solution, but also in order to deal with dynamical systems with delay (which can occur in some formulations of senescence in growth models). Our generic methodology could be applied to concrete problems, and allows the development of decision support tools in agriculture for a more efficient water resources management.

Considerando que a batata é o terceiro produto alimentar mais importante no mundo é necessária sua preservação e adaptação para as diferentes comunidades e condições ambientais do planeta, pois a consequência da redução da produção desse alimento pode ser a fome em todo o mundo. Um potecial causador desse problema é o aquecimento global, que é cada vez mais aceito pela ciência e as mudanças climáticas que vêm acontecendo no planeta. Alguns estudos sobre o efeito do aquecimento global e também mais especificamente do estresse hídrico sobre a cultura da batata estão sendo realizados, e são analisados os efeitos sobre cada parte da planta, como folhas, brotos, raízes, etc, porém o estudo sobre a raiz da batata é realizado de forma invasiva, ou seja, é necessário remover a planta do substrato. Nesse trabalho, apresentamos uma técnica para o estudo dos efeitos do estresse hídrico sobre a raiz da batata de forma não invasiva, portanto, os estudos serão realizados sem a remoção da planta do substrato. Dessa forma, poderão ser acompanhados os efeitos do estresse hídrico na planta em todos os estádios do desenvolvimento. Além disso, pode-se acompanhar o crescimento natural da raiz, diferentemente de outros modelos de estudo. A análise foi realizada com amostras da cultivar Ágata, plantadas em substrato sem substâncias paramagnéticas, e para isso foi utilizada a cultura hidropônica. Foram realizadas Imagens de Ressonância Magnética e em seguida um processamento e quantificação das imagens através da ferramenta matemática Multifractal. A técnica mostrou-se promissora para esse estudo, pois parâmetros multifractais mostraram-se sensíveis ao estresse hídrico, portanto, poderão ser realizados futuros estudos em outras cultivares de batata sob efeito do estresse hídrico. / Considering that potato is the third most important food product in the world, it is necessary its preservation and adaptation to different communities and environmental conditions on the planet, because the consequence of reducing the production of that crop may be the hunger of people around the world. With global warming, which is increasingly more accepted by science, and the climate changes that are happening on the planet it is necessary to generate new genotypes more resistant to these changes, as well as the generation of varieties suitable for tropical climates. Some studies on the effect of global warming and also more specifically on water stress on potato crops are being conducted. In these studies, one analyze the effects on every part of the plant, such as leaves, shoots, roots, etc., but the study on potato root is conducted invasively, i.e., to observe the result is necessary to remove the plant from the substrate. In this work, we present a technique for studying the effects of water stress on the potato root in a noninvasively way, therefore, various studies may be performed without requiring the removal of the plant from the substrate. Thus, the studies may accompany the effects of water stress on the plant at all stages of development. In addition, this tool allows the observation and monitoring of the natural growth of the root, unlike the other study designs. The analysis was performed with samples of cultivar Agata, planted in cups with substrate containing no paramagnetic substances, and to make this possible hydroponic culture was used. Magnetic Resonance Imaging studies were performed followed by processing and quantification of the images obtained through the mathematical tool Multifractal . The technique has shown promising for this study because multifractal parameters were sensitive to water stress, so future studies can be conducted in other potato cultivars under effect of water stress.