Karina Santos Garcia -Co-orientadora / Submitted by Hora Fontes Nadja Maria (pospetro@ufba.br) on 2012-11-12T19:12:35Z No. of bitstreams: 1 DISSERTA_ C L N ANDRADE.pdf: 4887549 bytes, checksum: 9a878f6bec7244405e18e8330d1b1b80 (MD5) / Made available in DSpace on 2012-11-12T19:12:35Z (GMT). No. of bitstreams: 1 DISSERTA_ C L N ANDRADE.pdf: 4887549 bytes, checksum: 9a878f6bec7244405e18e8330d1b1b80 (MD5) Previous issue date: 2012-04-04 / FAPESB; CAPES / Este trabalho apresenta um estudo biogeoquímico no estuário do rio Passa Vaca, situado em área urbana da cidade de Salvador, Bahia. Para o estudo da morfologia foliar foram estabelecidas três áreas de amostragem, nas quais foram selecionaas três árvores de cada espécie obrigatória de manguezal presente (Laguncularia racemosa (L.) Gaertn e Rhizophora mangle L.) e coletadas 30 folhas adultas em cada. Foram avaliadas: as medidas biométricas; as características externas (necrose tecidual, clorose, perfurações, bordas revolutas e manchas escuras); e as características internas (disposição dos diversos tecidos, presença de glândulas, de galhas, drusas, dentre outras estruturas) por meio de cortes histológicos. Para o estudo das demais variáveis foram estabelecidos dois transectos nas margens do rio, nos quais foram demarcados 15 pontos de amostragem com 60 m² cada. Para a avaliação da estrutura da vegetação, foram contados e mensurados alturas e circunferências de todos os indivíduos, das espécies obrigatórias de manguezal presentes. Para o estudo químico foram também coletadas, em cada ponto dos transectos, 30 folhas adultas, porções de sedimento de superfície, e estimados os parâmetros não conservativos: pH, Eh, temperatura e salinidade, na água intersticial e no sedimento e o Oxigênio Dissolvido (OD) nas águas superficiais do rio. Foram determinados os elementos: Zn, Cu, Fe, Mn, Na, K, Ca, Al nas folhas e nos sedimentos, além de Mg nas folhas; e os teores de P, Carbono Orgânico Total (COT), N, granulometria e isótopos de nitrogênio (δ 15 N) e carbono (δ 13 C) nos sedimentos. Os resultados demonstraram que a espécie Laguncularia racemosa (L.) Gaertn teve maior dominância na área estudada e que o bosque estudado se encontra em estágio maduro de desenvolvimento. Á nível morfológico as espécies apresentaram muitas adaptações relacionadas à manutenção da homeostase e para a sobrevivência em ambiente antropizado. Além disso, foram observadas muitas necroses e fragilidades teciduais, sobretudo na espécie Laguncularia racemosa (L.) Gaertn. Entretanto, a composição química e a morfologia das folhas, no geral, não diferiram de outros estudos em áreas de manguezal também impactadas por atividades antrópicas, com exceção para as concentrações de K, que estiveram abaixo do referenciado pela literatura. Nos sedimentos foram encontradas concentrações de Cu e Fe acima do referenciado pela literatura em alguns pontos e foram observadas correlações entre a temperatura do sedimento e a densidade de indivíduos mortos, além de associações entre densidade de Rhizophora mangle L. e a composição química do substrato. Também foram observadas correlações sedimento/ planta na concentração dos nutrientes avaliados, contudo, os fatores de concentração para os metais pesados estiveram abaixo de 1,0, indicando baixa absorção destes pelas plantas. A razão molar C/N e isotópicas δ 13 C e δ 15 C indicaram que um percentual considerável da matéria orgânica na área estudada é de fonte terrestre, sendo proveniente da vegetação do próprio manguezal. Assim, ficou evidenciado que a vegetação do estuário do rio Passa Vaca atua como barreira biogeoquímica no transporte e exportação de metais para o manguezal e o ecossistema costeiro adjacente. / Salvador

Magister Scientiae (Biodiversity and Conservation Biology) / The last taxonomic treatment of the subtribe Anthosperminae Benth. (Rubiaceae, Rubioideae, Anthospermeae) was in 1986 by Puff., nevertheless, few attempts have been made to resolve the phylogeny and the inter- and infrageneric relationships within the subtribe. The genera Anthospermum L. (39 species) and Nenax Gaertn. (11 species) are considered the most difficult groups to distinguish. Anthospermum species are widely distributed in Sub-Saharan Africa and Madagascar with the highest concentration of taxa in southern Africa, while Nenax species are restricted to southern Africa, in the south-western Cape Floristic Region. The two genera share common morphological and anatomical characters such as the growth form, presence of hairs on the stem, leaf arrangement, presence of petioles, flowers formation, dehiscence and presence of carpophore in fruits. currently combination of characters, woody shrub, needle-like leaves, few-flowered inflorescence and dioecy are considered unique in Nenax. The most recent phylogenetic analysis based on molecular data indicated insights into generic relationships within the two genera and the subtribe Anthosperminae. The present study focussed on expanding the phylogenetic analysis of Anthospermum, Nenax and other genera within the subtribe, as well as assessing the value of selected morphological and anatomical characters for re-assesing generic circumscriptions. Phylogenetic relationships were analysed using Maximum Parsimony, Maximum Likelihood and Bayesian inference, and a Maximum Clade Credibility tree was produced. These analyses were based on both nuclear (ITS, ETS) and plastid (trnL-f, rps16, rpl32) datasets.

>Magister Scientiae - MSc / The last taxonomic treatment of the subtribe Anthosperminae was in 1986 by Puff., nevertheless, few attempts have been made to resolve the phylogeny and the inter- and infrageneric relationships within the subtribe. The genera Anthospermum L. (39 species) and Nenax Gaertn. (11 species) are considered the most difficult groups to distinguish. Anthospermum species are widely distributed in Sub-Saharaan Africa and Madagascar with the highest concentration of taxa in southern Africa, while Nenax species are restricted in southern Africa, south-western Cape Floristic Region. The two genera share common morphological and anatomical characters.

A study was made of factors that influence production of different numbers of flower stalks of crested wheatgrass on grazed and ungrazed areas. Both laboratory and field studies were made. Greatest response in flower stalk production resulted from application of nitrogen in the field, amounting to an increase of from 5 to 10 times the numbers of flower stalks on untreated areas. Responses of plants in the greenhouse supported these results. Plants grown in the dark indicated that higher carbohydrate reserves existed in ungrazed than in grazed plants. It was concluded that a high carbohydrate-low nitrogen balance was the primary factor in low production of flower stalks on ungrazed range. Removing photosynthetic tissue by grazing reduced the amount of root growth and amount of carbohydrates stored as reserves. On grazed range some stored carbohydrates are used in production of regrowth and new tillers giving a more favorable carbohydrate-nitrogen balance for production of flower stalks. Whether nitrogen is a primary or secondary factor in production of flower stalks depends upon the stage of plant development in which it is the limiting factor. Leachate from old growth showed no effect on production of flower stalks. Treatment with gibberellic acid suppressed flower stalk production on plants transferred to the greenhouse prior to beginning spring growth, and to a lesser extent on plants transferred after beginning spring growth. The effect was attributed primarily to the stimulation of rapid, increased growth and depletion of reserves required for differentiation and production of flower stalks. Plants produced increased numbers of flower stalks with exposure to outside cold temperatures at least up to 10 weeks' duration, which was the maximum period tested. Under field conditions, grazed plants would be subject to more rigorous temperatures than ungrazed plants, but this was believed to be a minor factor contributing to the greater numbers of flower stalks on grazed plants compared to carbohydrate-nitrogen relationships. Reduced light was shown to be a factor contributing to reduced numbers of flower stalks in the greenhouse and in an outside lath house. Reduced light was believed to be a minor factor, however, in contributing to the low numbers of flower stalks on ungrazed areas. Results of the present study indicate that the carbohydrate-nitrogen balance in plants is a better criterion for intensive management of range lands than carbohydrate reserves alone.

La méthode microgravimétrique statique a permis d’observer que la pulpe de l’aiélé est plus hygroscopique que l’amande de karité à 25°C. A l’inverse, on fait l’observation contraire entre 35 et 55°C. Le modèle d’Oswin décrit le mieux les données de sorption des deux produits sur toute la gamme d’activité de l’eau. Les isothermes de l’amande de karité et de la pulpe de l’aiélé présentent le phénomène d’hystérésis entre 25 et 55°C. La conservation de ces oléagineux doit s’effectuer dans une atmosphère d’humidité relative comprise entre 40 et 60% afin d’obtenir des teneurs en eau recommandées. Un modèle adapté de prédiction des isothermes de sorption de ces oléagineux en deçà de 25°C et au delà de 55°C a été obtenu. L’extraction de la matière grasse au CO2 supercritique donne des rendements inférieurs à ceux obtenus de l’extraction à l’hexane. L’indice d’acide des matières grasses extraites au CO2 est supérieur à celui des lipides extraits à l’hexane. Ces indices, pour les lipides extraits des produits stockés à 18°C, sont les plus élevés. Quelque soient le mode de stockage et le solvant d’extraction, l’indice d’iode baisse avec le stockage. Le CO2 présente une sélectivité vis-à-vis de l’acide linolénique. Les lipides extraits au CO2 présentent les taux d’acides gras libres les plus élevés. Il ressort des résultats que le stockage -33°C est le meilleur. Toutefois, il ne doit pas dépasser 5 mois. L’extraction des lipides au CO2 supercritique doit utiliser les fruits frais ou stockés à -33°C. Les produits stockés à 18°C sont les plus durs et la dureté est corrélée négativement à la teneur en eau, mais positivement à l’indice d’acide des matières grasses extraites / The static microgravimetric method permitted to observe that the Canarium pulp was more hygroscopic at 25°C than the sheanut kernels. On the other hand, sheanut kernel was more hygrocopic in the temperature range 35°C-55°C. The Oswin model best described the sorption data of the two products in the whole water activity range. Hysteresis was observed in the entire temperature range 25-55°C for sheanut kernel and Canarium pulp. It is suggested that these products should be stored in an environment with a relative humidity of 40-60%, in order to attain the recommended moisture content for storage. A model was adapted to predict the sorption isotherms of shea and Canarium below 25°C and above 55°C. The oil yields obtained with supercritical CO2 were lower than those obtained with hexane. The acid values of butter and oil extracted with carbon dioxide were greater than those of lipids extracted using hexane. The acid values of samples stored at 18°C were the largest. The iodine value of the oils decreased with an increase of the storage period, irrespective of the storage temperature and the solvent used for extraction. The extraction with CO2 did not extract linolenic acid. The proportion of free fatty acids increased when carbon dioxide was used for extraction. From the foregoing, it is suggested that storage at -33°C for up to 5 months presents the best means of preserving these products. Only fresh or fruits stored at -33°C should be used for the extraction of lipids using carbon dioxide. The products stored at 18°C were the most hard and the hardness was correlated negatively to the water content, but positively to the acid value of fatty material extracted

Goosegrass [Eleusine indica (L.) Gaertn.] and smooth crabgrass [Digitaria ischaemum (Schreb.) Schreb. ex Muhl.] are problematic weeds in bermudagrass and creeping bentgrass turf. Increased incidences of herbicide resistant weed populations and severe use restrictions on formerly available herbicides have increased need for selective, postemergence control options for these weeds in creeping bentgrass and bermudagrass turf. This weed management exigency has led turf managers to utilize less effective, more expensive, and more injurious options to manage goosegrass and smooth crabgrass. Although potentially injurious, topramezone can control these weeds, especially goosegrass, at low doses. Low-dose topramezone may also improve bermudagrass and creeping bentgrass response. An initial investigation of three 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibiting herbicides in different turf types showed that Kentucky bluegrass, perennial ryegrass, and tall fescue were highly tolerant to topramezone, while creeping bentgrass and bermudagrass could tolerate topramezone doses that may control grassy weeds. Further investigation suggested that frequent, low-dose topramezone applications or metribuzin admixtures could enhance weed control and may conserve turfgrass quality. A novel mixture of topramezone at 3.7 g ae ha-1 and metribuzin at 210 g ai ha-1 controlled goosegrass effectively and reduced bermudagrass foliar bleaching associated with topramezone 10-fold compared to higher doses of topramezone alone in 19 field and 2 greenhouse trials. In an attempt to further enhance bermudagrass tolerance to topramezone, post-treatment irrigation was applied at various timings. When bermudagrass turf was irrigated with 0.25-cm water at 15 or 30 minutes after herbicide treatment, bermudagrass injury was reduced to acceptable levels when following low-dose topramezone plus metribuzin but not when following high-dose topramezone alone. Goosegrass control was reduced significantly by post-treatment irrigation in all cases, while irrigation reduced goosegrass control by low-dose topramezone plus metribuzin to below-commercially-acceptable levels. Novel, low-dose, frequent application programs containing topramezone or siduron were developed for season-long crabgrass or goosegrass control on creeping bentgrass greens. Greens-height creeping bentgrass quality was preserved following five biweekly treatments of siduron at rates between 3,400 to 13,500 g ai ha-1 and topramezone at 3.1 g ha-1. Siduron programs controlled smooth crabgrass and suppressed goosegrass while topramezone programs controlled goosegrass and suppressed smooth crabgrass. In laboratory and controlled-environment experiments, goosegrass absorbed three times more 14C than bermudagrass within 48 hours of 14C-topramezone treatment. Bermudagrass also metabolized topramezone twice as fast as goosegrass. Metribuzin admixture reduced absorption by 25% in both species. When herbicides were placed exclusively on soil, foliage, or soil plus foliage, topramezone controlled goosegrass only when applied to foliage and phytotoxicity of both bermudagrass and goosegrass was greater from topramezone than from metribuzin. Metribuzin was shown to reduce 21-d cumulative clipping weight and tiller production of both species while topramezone caused foliar discoloration to newly emerging leaves and shoots with only marginal clipping weight reduction. These data suggest that selectivity between bermudagrass and goosegrass is largely due to differential absorption and metabolism that reduces bermudagrass exposure to topramezone. Post-treatment irrigation likely reduces topramezone rate load with a concomitant effect on plant phytotoxicity of both species. Metribuzin admixture decreases white discoloration of bermudagrass by decreased topramezone absorption rate and eliminating new foliar growth that is more susceptible to discoloration by topramezone. / Doctor of Philosophy / Goosegrass and smooth crabgrass are problematic weeds in bermudagrass and creeping bentgrass turf. Increased incidences of herbicide resistant weed populations and severe use restrictions on formerly available herbicides have increased need for selective, postemergence control options for these weeds in creeping bentgrass and bermudagrass turf. Although potentially injurious, topramezone (Pylex™) can control these weeds, especially goosegrass, at low doses. Low-dose Pylex™ may also improve bermudagrass and creeping bentgrass response. An initial investigation evaluating tembotrione (Laudis®), Pylex™, and mesotrione (Tenacity®) in different turfgrass species showed that Kentucky bluegrass, perennial ryegrass, and tall fescue were highly tolerant to Pylex™ at rates ranging from 0.75 to 2.25 fl. oz./A, while creeping bentgrass and bermudagrass were low to moderately tolerant to Pylex™. Further investigation suggested that frequent, low-dose (less than 0.25 fl. oz./A) Pylex™ applications or metribuzin (Sencor®) admixtures could enhance weed control and may conserve turfgrass quality. A novel mixture of Pylex™ at 0.15 fl. oz./A and Sencor® at 4 oz. wt./A controlled goosegrass effectively and reduced bermudagrass injury to near acceptable levels and significantly less than Pylex™ applied alone at 0.25 fl. oz/A. In an attempt to further enhance bermudagrass tolerance to Pylex™, post-treatment irrigation was applied at different timings. When bermudagrass turf was irrigated at 15 or 30 minutes after herbicide treatment, bermudagrass injury was reduced to acceptable levels when following Pylex™ at 0.25 fl. oz./A plus Sencor® at 4 oz but not when following Pylex™ applied alone at 0.5 fl. oz./A. Goosegrass control was reduced significantly by post-treatment irrigation in all cases, while irrigation reduced goosegrass control by low-dose Pylex™ plus Sencor® to below-commercially-acceptable levels. Novel, low-dose, frequent application programs containing Pylex™ or siduron (Tupersan®) were developed for season-long crabgrass or goosegrass control in creeping bentgrass greens. Greens-height creeping bentgrass quality was preserved following five biweekly treatments of Tupersan® at rates between 6 and 24 lb./A and Pylex™ at 0.125 fl. oz./A. Tupersan® programs controlled smooth crabgrass and suppressed goosegrass while Pylex™ programs controlled goosegrass and suppressed smooth crabgrass. The data from these studies indicate that utilizing low-dose Pylex™ in combination with Sencor® can impart acceptable bermudagrass safety while also controlling goosegrass effectively. For creeping bentgrass greens, the low-dose, frequent application of Tupersan® is the safest legal option for golf course superintendents to control smooth crabgrass effectively, while having some ability to suppress goosegrass.