Setaria viridis tem sido utilizada como organismo modelo para gramíneas com metabolismo C4, buscando elucidar processos biológicos de plantas. A importância das monocotiledôneas com o metabolismo de C4 deve-se ao melhor balanço fotossintético quando comparado às plantas com metabolismo C3 em condições climáticas com altas temperaturas, como as que prevalecem no Brasil. Setaria viridis representa um sistema modelo de grande importância para a agricultura brasileira, uma vez que tanto a produção brasileira de biocombustíveis como de alimentos está fortemente relacionada aos organismos C4. Os hormônios vegetais são cruciais no estabelecimento de órgãos complexos desde o zigoto até o desenvolvimento da planta adulta. A auxina em particular, desempenha um papel fundamental na formação de um complexo sistema radicular nas plantas. Sabe-se que o transporte polar desse hormônio concentra a auxina em determinados tecidos, desempenhando um papel essencial na expressão diferencial de genes que modulam o desenvolvimento dos vários órgãos da planta. Monocotiledôneas e em particular Poaeceaes exibem um complexo sistema radicular que parece ser chave para o seu vasto potencial adaptativo, mas pouco se sabe sobre os fatores que envolvem as respostas sensoriais e de desenvolvimento que guiam a escolha de quais tipos de raiz as plantas elegem. O objetivo deste estudo foi explorar as vias hormonais e abióticas que influenciam a arquitetura das raízes / Setaria viridis has been used as a model organism for grasses with C4 metabolism, seeking to elucidate plant biological processes. The importance of monocotyledons with C4 metabolism is due to better photosynthetic balance when compared to plants with C3 metabolism in climatic conditions with high temperatures, such as those that prevail in Brazil. Setaria viridis represents a model system of great importance for Brazilian agriculture since both the Brazilian production of biofuels and food is strongly related to C4 organisms. Plant hormones are crucial in the establishment of complex organs from zygote to the adult plant development. Auxin in particular, plays a key role in the formation of a complex radicular system in plants. The polar transport of this hormone is known to concentrate auxin in particular tissues, playing an essential roll in the differential expression of genes that will modulate the development of the various plant organs. Monocots and in particular Poaeceae display a complex radicular system that seems to be key for it vast adaptive potential, but little is known about the factors involving the sensing and developmental responses that guide the choice of which root types to elect. The aim of this study was to explore the hormonal and abiotic cues that influence the root architecture

Magistrantūros studijų baigiamajame darbe pateikiami žaliosios šerytės morfogenezės indukcija in vitro tyrimų duomenys. Darbo metodai: vertintas kaliaus susidarymo dažnis (%), ūglių susidarymo dažnis (%), ūglių skaičius iš eksplanto (vnt.) bei šaknų formavimosi dažnis (%). Darbo objektas: Setaria viridis L. Darbo rezultatai. Tyrimų rezultatai atskleidė skirtingą kaliaus, ūglių bei šaknų formavimosi dažnį, dėl skirtingų egzogeninių augimo reguliatorių derinio ir jų kiekio maitinamojoje terpėje. Žaliosios šerytės dediferenciacijos indukcija intensyviau vyko terpėse, papildytose didesniu auksinų nei citokininų kiekiu. Žaliosios šerytės kaliaus formavimosi dažnis varijavo priklausomai nuo egzogeninių augimo reguliatorių derinio indukcijos terpėje. Augimo reguliatorių derinys 2,0 mg l-1 2,4-dichlorfenoksiacto rūgšties + 0,4 mg l-1 6-furfurylamino purino skatino intensyvesnę dediferenciaciją in vitro kultūroje. Antrinė diferenciacija intensyviausiai vyko maitinamojoje terpėje, papildytoje 0,4 mg l-1 α naftilacto rūgšties ir 2,0 mg l-1 N6-(2-izopentil) adenino. Daugiausiai ūglių iš eksplanto susiformavo maitinamojoje terpėje, papildytoje 0,3 mg l-1 NAR + 2,0 mg l-1 2iP. Žaliosios šerytės rizogenezės procesą in vitro skatino augimo reguliatorių deriniai 2,0 mg l-1 2,4D + 0,4 mg l-1 KIN, 0,2 mg l-1 NAR + 2,0 mg l-1 2iP ir 0,4 mg l-1 NAR + 2,0 mg l-1 BAP. / The master work presents the results of increasing of green millet induction of morphogenesis in vitro studies. Method of the work - evaluated callus formation frequency (%), shoot formation rate (%), number of shoots per explant (units) and root formation frequency (%). Object of the work - of Setaria viridis L. The results of work. The results of research showed differences in callus, shoot and root formation frequency of different exogenous growth regulator combination and quantity of nutrient medium. Setaria viridis L dedifferentiation induction intensively was in medium, supplemented by more quantity of auxin than cytokinin. Setaria viridis L callus formation frequency varied depending on the exogenous growth regulators combination of induction medium. Combination of growth regulators for 2.0 mg l-1 2,4-dichlorophenoxy acetic acid + 0.4 mg l-1 6-purine furfuryl amine stimulated more intensive dedifferentiation in vitro culture. Secondary differentiation was most intensive in nutrient medium supplemented with 0.4 mg l-1 α naphthyl acetic acid and 2.0 mg l-1 N6-(2-isopentyl) adenine. The most shoots from the explant were formed in a nutrient medium supplemented with 0.3 mg l-1 NAA + 2.0 mg l-1 2iP. Setaria viridis L the process of rhizogenesis in vitro stimulated the growth regulators combinations 2.0 mg l-1 2,4 D + 0.4 mg l-1 KIN and 0.2 mg l-1 NAA + 2.0 mg l-1 2iP and 0, 4 mg l-1 NAA + 2.0 mg l-1 BAP.

The C₄ photosynthetic cycle acts to concentrate CO₂ around the enzyme Rubisco. By doing so, C₄ photosynthesis leads to increased radiation, water and nitrogen use efficiencies. As such, C₄ photosynthesis is the most productive form of photosynthesis known. Because it enables such high levels of productivity there are large international efforts to introduce C₄ photosynthesis into non-C₄ crop species such as rice. Kranz anatomy is a characteristic leaf cellular arrangement of concentric rings of bundle sheath and mesophyll cells around closely spaced veins and is crucial to C₄ photosynthesis in almost all known examples. Despite the fact that Kranz has evolved on over 60 times independently little is known about the genetic regulation of Kranz development, as attempts to elucidate Kranz regulators using conventional mutagenesis screens have provided few insights. However, the advent of next generation DNA sequencing technologies has enabled the interrogation of genetic networks at a previously unprecedented scale. The work in this thesis describes a genome-wide transcriptomic analysis of leaf development in maize, a C₄ species, that develops both Kranz-type and non-Kranz-type leaves. Detailed bioinformatics analyses identified candidate regulators of both Kranz development and additional aspects of maize leaf development. Three of the identified Kranz candidates were functionally characterised in both C₄ and non-C₄ species. Furthermore, expression and phylogenetic analyses of GOLDEN2-LIKE (GLK) genes, a small transcription factor family previously implicated in C₄ development in maize, were extended to determine the generality of GLK function in C₄ evolution.

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.

Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2017-02-07T17:06:02Z No. of bitstreams: 1 texto completo.pdf: 3400245 bytes, checksum: b57a0d743c1ea165d35b1ffebb7e5dbc (MD5) / Made available in DSpace on 2017-02-07T17:06:02Z (GMT). No. of bitstreams: 1 texto completo.pdf: 3400245 bytes, checksum: b57a0d743c1ea165d35b1ffebb7e5dbc (MD5) Previous issue date: 2016-07-19 / Fundação de Amparo à Pesquisa do Estado de Minas Gerais / A disponibilidade de gás oxigênio (O2) é uma das principais forças que moldam a evolução dos organismos vivos e é essencial para a sobrevivência das plantas. A deficiência parcial (hipóxia) ou total (anóxia) de gás oxigênio é componente importante do estresse de alagamento. Para o aprofundamento do conhecimento genético, a transcriptômica possibilita identificar genes envolvidos nos mecanismos de respostas, e a transformação desses genes em plantas permite avaliar seus efeitos. Com o objetivo de caracterizar genes responsivos à deficiência de oxigênio e identificar genes candidatos para tolerância ao alagamento, analisamos dados de RNA-seq de raízes das cultivares de soja Embrapa 45 (tolerante ao encharcamento do solo) e BR 4 (sensível ao encharcamento) sob hipóxia. Das diferenças entre as duas cultivares, Embrapa 45 apresentou menor número de genes up-, maior quantidade de genes down- regulados, e maior expressão dos genes que codificam phosphoglucomutase (Glyma05g34790), unknown protein related to N-terminal protein myristoylation (Glyma06g03430), protein suppressor of phyA-105 (Glyma06g37080) e fibrillin (Glyma10g32620). Dados de RNA-seq e qRT-PCR da hemoglobina não simbionte Glyma11g12980 indicaram divergência estrutural desse gene entre as cultivares. Em comum entre as duas cultivares, mudanças na abundância de transcritos envolvidos no metabolismo de aminoácidos e derivados sugerem perturbação destes em modificações do tRNA, acurácia/eficiência traducional e estresse do retículo endoplasmático (RE) sob hipóxia. Também observamos que grupos de genes (estáveis, up- e down-regulados) diferem quanto à frequência de elementos cis TATA box, ABREs (ABA-responsive elements) e CRT/DREs (C-repeat/dehydration-responsive elements), assim como em estrutura, composição e uso de códons sinônimos. Especulamos que cis elementos ABRE podem mediar expressão gênica independentemente de ABA em raízes de soja sob hipóxia. Por fim, a nosso conhecimento, somos os primeiros a demonstrar viabilidade de se transformar Setaria viridis (espécie modelo de monocotiledôneas C4) mediada por Agrobacterium por meio da técnica floral dip, que não demanda cultura de tecidos nem regeneração de plantas transgênicas. Assim como em arabidopsis, espécie modelo de dicotiledôneas C3, floral dip em S. viridis pode acelerar estudos genéticos e de genômica funcional (inclusive ao estresse de alagamento) de gramíneas importantes para alimentação humana e animal, fibras e biocombustíveis, tais como cana-de-açúcar, Miscanthus, capim- elefante, Brachiaria, sorgo e milho. / Oxygen gas (O2) availability is one of primary forces shaping the evolution of living organisms and essential for land plants survival. Partial (hypoxic) or total (anoxic) oxygen gas deficiency is important component of flooding stress. For deepening the genetic knowledge, transcriptomics identify genes involved in stress response mechanisms, and transformation of these genes in plants allows to evaluate its effects. In order to characterize genes responsive to oxygen deficiency and identify candidate flooding tolerance genes we analyzed root RNA-seq data from flood-tolerant Embrapa 45 and flood-sensitive BR 4 soybean cultivars under hypoxic stress. From differences between the two cultivars, Embrapa 45 showed less up- and more down-regulated genes, and stronger induction of phosphoglucomutase (Glyma05g34790), unknown protein related to protein N-terminal myristoylation (Glyma06g03430), protein suppressor of Phya- 105 (Glyma06g37080), and fibrillin (Glyma10g32620). RNA-seq and qRT-PCR data of non-symbiotic hemoglobin Glyma11g12980 indicated structural divergence of this gene between cultivars. In common between the two cultivars, transcriptional changes in amino acids and derivative metabolic process suggest its disturbance in tRNA modifications, translation accuracy/efficiency, and endoplasmic reticulum (ER) stress under hypoxia. In addition, genes groups (stable, up-, and down-regulated genes) differed in promoter TATA box, ABREs (ABA-responsive elements), and CRT/DREs (C-repeat/dehydration-responsive elements) frequency, as well as in structure, composition, and codon usage. We speculate that cis-acting ABREs can mediate gene expression independent of ABA in hypoxic soybean roots. Finally, to our knowledge, we first report Agrobacterium-mediated transformation method in Setaria viridis (C4 monocotyledonous model species) using floral dip, which does not require tissue culture nor transgenic plant regeneration. As in arabidopsis, C3 dicotyledonous model species, floral dip in S. viridis may accelerate genetic studies and functional genomics (including flooding stress) of important food–feed–fiber–fuel grass crops such as sugarcane, Miscanthus, elephant grass, Brachiaria, Sorghum and maize.

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 in partial fulfillment of the requirements for the degree of Doctor of Philosophy Faculty of Science University of Witwatersrand Johannesburg SOUTH AFRICA / A three-year study was undertaken In the province of Mpumalanga, South Africa to Investigate the competitive effects of the grass Setaria megaphylla on the growth of the tree species Pinus patula. A replacement series field trial, where six different competition regimes were Implemented, clearly demonstrated the suppressive effects of S. ( Abbreviation abstract ) / AC2017

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%.

Thesis (Ph.D. (Animal Nutrition)) -- University of Limpopo, 2016 / Refer to document

Tillers are vegetative branches found in grasses, which develop in early stages of plant life. Located at the base of the central stalk, tillers have agronomical importance by increasing seed production with fewer tillers, or providing alternative forms of biofuel with more tillers. As grains have typically decreased tiller number while undergoing domestication, we explored wild and domesticated strains of varying grains by doing a morphological analysis on tiller development. This thesis shows how the decrease of tillers through in domestication cereals shows diversity not only across maize, Sorghum, and Setaria, but also between lines of maize and Setaria species. To do so, we first measured axillary bud growth across these grasses and compared bud initiation, growth, dormancy and outgrowth. While maize inbred B73 demonstrated a tiller dormancy pattern by initiating buds, growing buds and then bud dormancy we measured growth in Sorghum and Setaria to compare and found that although Sorghum patterns dormancy similar to maize, Setaria had more than one way tiller suppression not previously expected. We look further at Setaria buds with a statistical analysis of tiller origin and bud frequency in a wild strain and two domesticated strains of Setaria. Furthermore we performed Scanning Electron Microscopy (SEM) to have a clear understanding of bud initiation or lack of initiation in Setaria italica (B100) comparing it to its wild ancestor Setaria viridis. Because of the diversity in Setaria, we re-visited maize tiller domestication by taking bud measurements, performing SEMs and counting bud frequency on other strains of inbred maize. We found that maize also shows diversity in its patterning of tiller domestication. These results demonstrate that there is diversity in the patterns in which tiller domestication has occurred. This diversity is shown here through differences in tiller bud decisions to initiate or not initiate, or to have axillary buds go dormant post-initiation. Furthermore this variance is shown through differences in bud frequency counts, growth measurements, SEMs, and where tiller branches originate across the grains of maize, Sorghum and Setaria.