This investigation is concerned is concerned with how a commercial herbicide, dimethyl 2, 3, 5, 6-tetrachloroterephthalate (DCPA) affects the growth, morphology, and physiology of foxtail millet (Setaria italica (L.) Beav.). The objectives were to examine the nature of morphological changes, to determine what physiological and chemical changes accompanied the morphological alterations and to obtain information about the mechanism by which DCPA is herbicidal.

The theme of this thesis is the impact of water deficit on the concentration of proline and electrolyte leakage from representatives of the Panicoideae tribe. The impact of drought on agricultural production in the environment of the Czech Republic is currently an important issue. The exceptionall dry year of 2014/2015 and the associated water deficit in the soil had an impact mainly on the harvest of wide-row crops, including maize. Representatives of the Panicoideae tribe - sorghum and foxtail millet are the most drought-resistance crops in the world. Sorghum and foxtail millet belong to II. group of cereals like maize. Sorghum and foxtail millet show lower transpiration coefficient than maize, they also tolerates less demanding growing conditions and are more resistant to diseases and pests. They also compete with maize in a wide range of applications. It is therefore appropriate to determine how these crops respond to water deficit during their ontogenetic development. For the purposes of this experiment genotypes originating from conditions of temperate climate were selected, this genotypes have a shorter growing season. A short growing season is an important factor in the timing of the harvest of the late sown crops in our climate. The aim of the thesis was to determine and evaluate the impact of water deficit on the concentration of proline and electrolyte leakage in selected genotypes of sorghum and foxtail millet and on the basis of the results to select genotypes with high resistance to water deficit. Based on the aims the following hypotheses were set: to determine whether there are differences in the concentration of proline and electrolyte leakage between selected genotypes depending on the effect of water deficit and whether there are differences in these physiological characteristics in response to water deficit between sorghum and foxtail millet. To fulfill the objectives and evaluation the hypothesis was based on the greenhouse experiment with selected genotypes of sorghum and foxtail millet at the Department of Botany and Plant Physiology in the Czech University of Life Sciences Prague. The experiment included 4 genotypes of the species Sorghum bicolor (L.) Moench. (Sorghum): 1216, 30485, Barnard Red and Ruzrok and one variety of the species Setaria italica (L.) Beauv. (Foxtail millet) Ruberit. A total of 4 variants were designated for the experiment (one control and three under the influence of water deficit in different times). The plants in the control variant were full irrigated throughout the experiment. Variant KS was irrigated for the first 14 days, followed by 10 days without watering and the last 4 days were again irrigated. Plants in variant SK were under the influence of water deficit for the first 10 days of the experiment, then 18 days with watering and the plants in the variant SS were without watering for the first 10 days, for the next 4 days were without watering, then the same pattern was repeated: 10 days without and 4 days with watering. Physiological characteristics were observed in plants in the developmental stages BBCH 14-16. The concentration of proline was determined by measuring the absorbance of the samples formed by the reaction with ninhydrin. Subsequently, the measured values were compared with the calibration curve. To measure the sample absorbance at 520 nm a spectrophotometer Hellios gama (Thermo) was used. Electrolyte leakage on discs made from leafs was measured with electrical conductivity meter GRYF 158 (HB Griffin, Ltd.). The obtained results show that the proline concentration increased in response to water stress, since the highest concentration of proline was detected in plants growing in the most stressed variant of SS (670.13 micrograms) compared with other variants of stress. Plants variant KS (643.85 micrograms) showed a higher accumulation than the proline in variant SK (636.69 micrograms). The highest concentration of proline was measured on a genotype in the variety of sorghum Ruzrok (642.94 micrograms). The lowest content of proline was found in the variety of sorghum 1216 (623.78 micrograms), this value was also the only significant difference from the contents of proline to other genotypes. Which at least partly confirms the proposed hypothesis that there are differences in the content of proline between genotypes. The highest electrolyte leakage cell damage was respectively exhibited in plants from the variant SS (39.56%). Plants of the SK variant showed a higher rate of cell damage (32.95%) than plants from the variant KS (29.88%). The lowest cell damage was exhibited in plants grown under control conditions, which again indicates that damage cells increases in response to water deficit. In this experiment the highest degree of cell damage was found in the variety of sorghum 1216 (29.26%) and lowest cell damage was observed in the variety of sorghum Ruzrok (27.03%). A significant different degree of cell damage appeared only in the variety foxtail millet Ruberit (28.6%), which confirms our hypothesis that there are differences in the electrolyte leakage between sorghum and foxtail millet. The hypotheses were not fully confirmed by the experiment. Nevertheless, on the basis of obtained results we conclude that the least drought-resistance genotype is the 1216 variety and the best adapted to the water deficit was the Ruzrok variety. It also confirmed that the higher proline accumulation may protect the plant against the negative effects of water deficit on the cell membranes, which is then reflected in a reduced electrolyte leakage.

Orientadora: Profª. Drª. Nathalia de Setta Costa / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Biotecnociência, São Bernardo do Campo, 2018. / A seca é o estresse abiótico que mais impacta as plantas cultivadas, influenciando diretamente na sua reprodução e sobrevivência. Setaria italica é uma gramínea com fotossíntese C4, tolerante à seca, que recentemente foi eleita como espécie modelo de plantas monocárpicas com importância comercial, como a cana-de-açúcar e o milho. Para avaliar os padrões de resposta à seca em S. italica, foi realizado um experimento em que plantas foram cultivadas em um gradiente de estresse hídrico, constituído por cinco condições de rega, de acordo com a porcentagem de água perdida por evapotranspiração. As plantas foram cultivadas em vasos utilizando uma câmara de crescimento com fotoperíodo de 16/8 horas de claro/escuro, com temperatura e umidade controladas. Para avaliar a aptidão de S. italica à seca foram realizadas medidas de fitness a cada duas semanas e medidas as taxas líquidas de trocas gasosas nos 38º e 48º dias após o início do tratamento. Além disso, após 44 dias de tratamento foram coletadas folhas para análises do teor relativo de água foliar e do perfil metabólico por GC/MS. Os resultados mostraram que o sistema de rega aplicado foi bem-sucedido para os cinco tratamentos levando a um gradiente de resposta entre o nível de estresse hídrico e a sobrevivência e reprodução de S. italica. Essa resposta foi associada a menores taxas fotossintéticas e de transpiração nos tratamentos 30 % e 0 %, o que pode ter levado a prejuízos na assimilação de carbono. Além disso, foi observada uma maior eficiência no uso da água para as plantas submetidas ao estresse hídrico. Quanto ao perfil por GC/MS, foram identificados 27 metabólitos diferentes, entre eles, aminoácidos, ácidos orgânicos, açúcares e polióis. Contudo, não foram observadas alterações importantes dos metabólitos associado ao tratamento de déficit hídrico. Como conclusão podemos sugerir que S. italica deve consegui manter o ciclo do ácido tricarboxílico em níveis comparadas ao controle mesmo em condições de água limitada e de menores taxas de assimilação de carbono. Os dados dessa dissertação serão associados a perfis de expressão gênica para contribuir com o entendimento das estratégias utilizadas por monocotiledôneas C4 para tolerar a seca e permitir a seleção de genes candidatos para futuros estudos funcionais e de melhoramento vegetal. / Drought is the abiotic stress that most impacts on cultivated plants, influencing their reproduction and survival. Setaria italica is a drought-tolerant C4 photosynthesis grass, which has recently been selected as a model species for monocarpic crops such as sugarcane and maize. In order to evaluate the drought responses in S. italica, we carried out an experiment in which plants were cultivated in a water stress gradient, which consisted of five watering conditions, selected according to the percentage of water lost by evapotranspiration. Plants were grown in pots and in an air-conditioned greenhouse with 16 h photoperiod. To understand the reproduction and survival ability of S. italica under water stress, we evaluated fitness parameters every two weeks and measured the instantaneous rates of gas exchange at the 38 th and 48 th days after the beginning of the drought treatment. In addition, after 44 days after the beginning of the drought treatment, leaves were collected for analysis of the relative water content and the metabolic profile by GC/MS. The results show that the applied irrigation system was successful for the five treatments leading to a response gradient between the water stress level and the survival and reproduction of S. italica. This is probably due to a lower photosynthetic rate and transpiration for the plants of the treatments 30% and 0%, which led to losses in carbon assimilation. In addition, we showed a greater efficiency in the use of water for plants submitted to water stress. The GC/MS profile allowed to identify 27 metabolites, among then, amino acids, organic acids, sugars and polyols. However, there were no significant metabolite alterations associated with the treatment of water deficit. As conclusion, we suggest that S. italica should be able to maintain the citric acid cyle even under limited water supply and lower levels of carbon assimilation. The data presented here will be associated to gene expression profiles to contribute to the understanding of the strategies used by C4 monocotyledons to tolerate drought and to allow the selection of candidate genes for further functional studies on plant breeding.

Submitted by Cássio da Cruz Nogueira (cassionogueirakk@gmail.com) on 2017-02-13T15:05:20Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_CaracterizacaoAnaliseFluidodinamica.pdf: 3237831 bytes, checksum: 5f045c8c482eb95d5900ad403c2b6fc5 (MD5) / Approved for entry into archive by Edisangela Bastos (edisangela@ufpa.br) on 2017-02-15T16:20:09Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_CaracterizacaoAnaliseFluidodinamica.pdf: 3237831 bytes, checksum: 5f045c8c482eb95d5900ad403c2b6fc5 (MD5) / Made available in DSpace on 2017-02-15T16:20:09Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_CaracterizacaoAnaliseFluidodinamica.pdf: 3237831 bytes, checksum: 5f045c8c482eb95d5900ad403c2b6fc5 (MD5) Previous issue date: 2014-05-16 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / Realizou-se a caracterização química, física e qualitativa das sementes de painço (S. italica) e em seguida, foi avaliado o comportamento fluidodinâmico, à temperatura ambiente, para diferentes cargas de material em duas configurações de leito de jorro: cônico (500, 800, 1100 e 1400 g) e convencional (1300, 1700 e 2100 g). A partir dos dados experimentais foi verificado que as partículas eram adequadas ao sistema utilizado, partindo então para a obtenção dos parâmetros operacionais característicos do jorro, os quais foram comparados com seus respectivos valores teóricos calculados por correlações empíricas disponíveis na literatura. Ao avaliar as condições experimentais, foi necessário optar por apenas uma das configurações de leito de jorro, prevalecendo o leito convencional. Em seguida, foi definida uma carga ótima de painço (1700 g) e deu-se prosseguimento à análise da cinética de secagem das sementes em leito de jorro convencional nas temperaturas de 44, 65 e 86°C por 132 min, verificando-se a ausência de taxa de secagem constante, indicando que a secagem foi controlada pelos mecanismos de difusão. O coeficiente de difusão efetivo das sementes de painço correspondeu a valores entre 0,7729x10-11 e 2,3189x10-11 m2/s e o valor de energia de ativação foi quantificado por meio da equação de Arrhenius, correspondendo à 24,86 kJ/mol. Os modelos matemáticos que melhor descreveram a curva de secagem foram Aproximação por Difusão, Page e Midilli et al. Além disso, foi aplicado um planejamento composto central rotacional com o objetivo de avaliar a influência das variáveis independentes tempo (X1) e temperatura (X2) nas respostas razão de umidade (XR), porcentagem de germinação (G) e índice de velocidade de germinação (IVG). As respostas selecionadas são determinantes no controle de qualidade de sementes, como no caso do teor de umidade, o qual deve ser adequado para o armazenamento. As respostas G e IVG são indicações do estado fisiológico da sementes, o que também é importante, de acordo com a finalidade do produto. Por meio das análises estatísticas, para um intervalo de confiança de 95%, verificou-se que XR e IVG sofreram influência apenas de X1, X2 e X22, enquanto G foi estatisticamente influenciado por X2 e X22. Os efeitos, para todas as respostas, foram negativos, indicando que XR e IVG decrescem com o aumento da temperatura e tempo de secagem enquanto G reduz com o aumento da temperatura. Por meio dos resultados estatísticos, foram propostos modelos quadráticos para as respostas analisadas, alcançando-se bons coeficientes de correlação (R2): 0,9632 (XR), 0,8999 (G) e 0,9724 (IVG). Posteriormente, foi determinado o ponto ótimo durante a secagem de sementes de painço em leito de jorro, por meio da Função desejabilidade, o qual foi correspondente a um tempo de secagem de 121 min à uma temperatura de 64°C, obtendo-se sementes com um percentual germinativo de 82,99% ; índice de velocidade de germinação de 29,33 (adimensional) e teor de umidade final igual a 11%. / S. italica seeds were analyzed in chemical, physical and qualitative aspects and then the fluidynamics was evaluated at ambient temperature, for different loads of material in two spouted bed configurations: conical (500, 800, 1100 and 1400 g ) and conventional ( 1300, 1700 and 2100 g). From the experimental data it was found that the particles were suitable for the system used, so the operating parameters of the spouted bed were collected , which were compared with their theoretical values calculated by empirical correlations available in literature. According to experimental conditions, it was necessary to choose only one of the configurations of spouted bed, so it was decided to operate the conventional spouted bed. For the seed drying kinetics only the optimal load (1700g) was utilized and the temperatures used were 44 , 65 and 86 °C, verifying the absence of constant drying rate, indicating that drying was controlled by diffusion mechanisms. The effective moisture diffusivity was estimated, resulting in the range from 0.7729x10-11 to 2.3189x10-11 and the relationship between the temperature and the effective moisture diffusivity was described by Arrhenius equation, providing an activation energy of 24,86 kJ/mol. The mathematical models that best described the drying curve were Diffusion Approximation, Page and Midilli et al. Furthermore, a rotational central composite design was applied with the objective of evaluating the influence of the independent variables time (X1) and temperature (X2) on the responses moisture ratio (XR), germination (G) and speed germination index (SGI) . The chosen answers are necessaries in the seeds quality control, as in the case of the moisture content during the storage. The G and SGI responses are indicative of the physiological state of the seeds, which are also important, in accordance with the purpose of the product. Through statistical analysis, for a confidence interval of 95%, it was found that XR and SGI were influenced only by X1, X2 and X22 , while G was statistically affected by X2 and X22 . The effects for all responses were negative , indicating that SGI and XR decrease with increasing of temperature and drying time. The answer G decreases with increasing of temperature. Quadratic models were proposed by the statistical analyzes, reaching good correlation coefficients (R2); 0.9632 (XR), 0.8998 (G) and 0.9724 (SGI). Then, the optimal value of the foxtail millet drying process was determined, using the concept of Desirability Function, which was corresponding to a drying time of 121 min at a temperature of 64 ° C, getting seeds with 82.99% of germination; speed germination index of 29.33 (dimensionless) and final moisture content of 11%.