Variability in the relationship between tree leaf area (TLA) and selected stem measurements was examined in three Douglas-fir stands (Pseudotsuga menziesii (Mirb.) Franco, var. menziesii) that were less than 50 years-old, spaced to approximately 550 to 650 stems/ha, and differed in soil moisture and nutrients. Attention was given to the effect of mean annual ring width (MARW), cross-sectional area of the live bark (ALB - a surrogate measure of relative nutrient storage in the stem), and cross-sectional area of the most recent annual rings equal in number to the number of whorls in the live crown (ALC), on variability in the relationship between TLA and cross-sectional area of sapwood (ASW). At breast height, basal area, ASW, and cross-sectional area of sapwood plus live bark (ASWLB) were not linearly related to TLA, and linear regression equations using log transformed variables varied significantly between sites. Nonlinear regression equation for ASW at breast height was: TLA = 0.064ASẆ¹•³³ (I² = 0.856). Including D (the distance between breast height and the center of the live crown) in the nonlinear equation, did not significantly improve the regression. Tree leaf area prediction models using stem measures from the base of live crown (blc) had higher adjusted R² values than models using stem measures from breast height. At the blc, basal area, ASW, and ASWLB were linearly related to TLA (adjusted R² = 0.926, 0.908, and 0.934, respectively). Multiplying ASW by MARW did not improve the fit of the regression models. Multiplying ASW by ALB improved the linearity of the relationship of ASW at breast height to TLA. The best fitting TLA model overall used the product of ASW at blc and ALB at blc as the independent variable (adjusted R² = 0.967). The results indicate that research into the allometric relationship of TLA to stem measures should give consideration to more than hydraulic measures and include measures of bark function. At breast height and the blc, the independent variable ALC was linearly related to tree leaf area and had higher adjusted R² values than did ASW. In most trees the ALC stem measure was found to include a portion of heartwood area. The strong relationship between TLA and ALC suggests that a given transpiring leaf mass or area is related to a proportional amount of conducting stemwood and physical support stemwood. A quick alternative approach for estimating individual tree leaf area using photographs taken at fixed distance and angle from the target tree did not result in a reliable tree leaf area prediction technique. The difficulty of obtaining views of the tree crown which were not obstructed by adjacent tree crowns was the major obstacle. Using a fixed distance and camera angle was a problem because of variable tree heights. However, altering these fixed positions introduced additional variation into the tree leaf area estimation. Mean specific leaf area (SLA) varied significantly by site, needle age class, and crown position. Mean SLA per needle age class per branch can be predicted with 95% confidence and a 10% allowable error using six 10-needle samples. / Forestry, Faculty of / Graduate

Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2017-01-02T17:03:18Z No. of bitstreams: 1 texto completo.pdf: 563449 bytes, checksum: 9954957a43583d02d6ac39c5cd199d26 (MD5) / Made available in DSpace on 2017-01-02T17:03:18Z (GMT). No. of bitstreams: 1 texto completo.pdf: 563449 bytes, checksum: 9954957a43583d02d6ac39c5cd199d26 (MD5) Previous issue date: 2016-07-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O estado de Minas Gerais é o maior produtor de café arábica do país. Grande parte das lavouras do estado apresenta baixas produtividades devido ao inadequado manejo nutricional. A avaliação do estado nutricional, com base na diagnose foliar, é uma estratégia capaz de subsidiar o manejo nutricional dessas lavouras. Dentre os métodos usados para a interpretação dessas análises, o método proposto por Kenworthy, avalia o grau de balanço nutricional, que apresenta acepção quantitativa, considerando os nutrientes de forma individual além de incorporar a variabilidade do teor na população de referência. O balanço nutricional pode ser entendido como o grau de saciedade da “fome” da planta em relação ao nutriente. Já o Sistema Integrado de Diagnose e Recomendação (DRIS) proposto por Beaufils, avalia o grau de equilíbrio, por meio das relações duais entre nutrientes, o equilíbrio pode ser entendido como a “qualidade da dieta”. Os objetivos desse trabalho foram: 1) Obter curvas de resposta potencial (CRP) da cultura do café arábica em Minas Gerais com índices Kenworthy e DRIS, que expressam o estado nutricional quanto ao grau de balanço e de equilíbrio, respectivamente; 2) Propor faixas de suficiência quanto ao grau de balanço e de equilíbrio para a cultura do café arábica em Minas Gerais com base na técnica da linha de fronteira; 3) Diagnosticar o estado nutricional de lavouras de café arábica de Minas Gerais com base nas faixas de suficiência obtidas. Para tanto, foi utilizado um banco de dados contendo informações referentes aos teores totais foliares de N, P, K, Ca, Mg, S, Cu, Fe, Zn, Mn e B e produtividade, de três regiões representativas quanto a produção de café arábica no estado de Minas Gerais.Para compor a população de referência, foram consideradas todas as lavouras que apresentavam produtividade relativa superior a 44,03 %, sendo esta a produtividade relativa média das lavouras do ano de alta produtividade. As normas nutricionais foram obtidas dessa população de referência. A seguir com o auxílio do Nutri – Café Arábica, parametrizado com as normas obtidas no presente trabalho, foi realizada a diagnose do estado nutricional das 257 lavouras, pelos métodos Kenworthy e DRIS. Posteriormente, foram confeccionados gráficos de dispersão relacionando a produtividade relativa dos anos de alta produtividade, com os respectivos índices balanceados de Kenworthy e com os índices DRIS, estabelecendo-se para cada gráfico a linha de fronteira superior (LFS). Com base na LFS de cada relacionamento, equações foram ajustadas selecionando os pares de pontos que melhor se ajustou aos dados. Por meio da abordagem da LFS foram obtidas curvas de resposta potencial CRP para a cultura do café arábica em Minas Gerais, que expressem o estado nutricional quanto ao grau de balanço e de equilíbrio, respectivamente. Com base nas CRP foram obtidas faixas de suficiência quanto ao grau de balanço e de equilíbrio nutricional, para N, P, K, Ca, Mg, S, Cu, Fe, Zn, Mn e B. O emprego LFS permitiu à obtenção de faixas de suficiência com maior aplicabilidade dos aspectos biológicos. O uso das faixas de suficiência obtidas no presente trabalho permitiu avaliar o estado nutricional das lavouras. O uso do método da linha de fronteira permitiu determinar o grau de limitação à produtividade, em função do grau de balanço e de equilíbrio nutricional de cada nutriente, isolando os efeitos de fatores não nutricionais. / The state of Minas Gerais is the largest Arabica coffee producer in the country. Much of the state's crop has low productivity due to inadequate nutritional management. The assessment of nutritional status, based on leaf analysis is a strategy to support the nutritional management of these crops. Among the methods used for the interpretation of these analyzes, the method proposed by Kenworthy, assesses the degree of nutritional balance, which shows quantitative purposes, whereas the nutrients individually and incorporate variability of content in the reference population. The nutritional balance can be understood as the degree of fullness of the "hunger" of the plant in relation to nutrient. Already the Integrated Diagnosis and Recommendation (DRIS) proposed by Beaufils, assesses the degree of equilibrium, through the dual relationships between nutrients, the equilibrium can be understood as the "quality of the diet." The objectives of this study were: 1) Get potential response curves CRP of Arabica coffee crop in Minas Gerais with indexes Kenworthy and DRIS, expressing the nutritional status in the degree of balance and equilibrium, respectively; 2) Propose sufficiency tracks the degree of balance and equilibrium for arabica coffee crop in Minas Gerais based on the boundary line technique; 3) Diagnosing the nutritional status of Arabica coffee plantations in Minas Gerais based on obtained sufficiency ranges. Thus, a database was used containing information regarding the leaf total N, P, K, Ca, Mg, S, Cu, Fe, Zn, Mn and B and productivity, three representative regions as coffee production arabica in the state of Minas Gerais. To compose the reference population, they were considered all crops presenting higher relative productivity to 44.03%, which is the average relative productivity of the high productivity of the crop year. Nutritional standards were obtained this reference population. Then with the help of Nutri - Arabica Coffee, parameterized with standards obtained in this study, the diagnosis was made of the nutritional status of 257 crops, by Kenworthy and DRIS methods. Later, they were made scatter plots relating the relative productivity in the years of high productivity, with their balanced levels of Kenworthy and the DRIS indices, establishing for each the upper boundary line chart (LFS). Based on the LFS each relationship equations were adjusted by selecting the pairs of points that best fit the data. Through the LFS approach potential response curves were obtained (CRP) for Arabica coffee crop in Minas Gerais, which express the nutritional status in the degree of balance and equilibrium, respectively. Based on the CRP were obtained sufficiency ranges for the degree of balance and nutritional equilibrium for N, P, K, Ca, Mg, Cu, Fe, Zn, Mn and B. The use LFS allowed to obtain track sufficiency with greater applicability of biological aspects. The use of sufficiency ranges obtained in this study allowed us to evaluate the nutritional status of crops. The use of the boundary line method allowed us to determine the degree of limitation on productivity, depending on the degree of balance and nutritional equilibrium of each nutrient, isolating the effects of non-nutritional factors.

Orientador: Ivany Ferraz Marques Valio / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-07-18T01:28:41Z (GMT). No. of bitstreams: 1 Lucas_NeideMariaCordeiro_D.pdf: 11281257 bytes, checksum: bcaabeb20752eba2b06a83529009aafc (MD5) Previous issue date: 1983 / Resumo: Em Phaseolus vulgaris L. cv. carioca, a formação de raízes adventícias no pecíolo de folhas primárias ocorre a partir de células do parênquima floemático. Não foi observada formação de raízes a partir de células do pulvino. Nesta cultivar o pulvino inibe o enraizamento de estacas de folhas, independentemente da idade foliar. Na rizogênese de folha sem pulvino, as mais jovens apresentam pequeno número de raízes, mas sempre enraízam. Nem todas as folhas mais velhas enraízam, mas as que o fazem desenvolvem um grande número de raízes. A redução da área da lâmina foliar reduz o enraizamento de folhas sem pulvino, sendo a redução mais significativa pela eliminação da metade superior da lâmina, sugerindo o efeito de substâncias hormonais, além dos fotossintatos produzidos nesta região. Interrupção da nervura média da lâmina provoca enraizamento proporcional à área da lâmina relacionada com a secção. Tal enraizamento não afeta a rizogenese na base do pecíolo livre do pulvino. Bloqueio da fotossíntese com DCMU inibe totalmente o enraizamento evidenciando a necessidade de carboidratos para o estabelecimento da rizogênese. Indução de senescência com aplicação de vários períodos de escuro em folhas ligadas à planta ou destacadas e em condições de enraizamento mostrou que quando as folhas eram levadas para as condições de enraizamento na luz, a rizogênese só ocorreu quando o período de pré-tratamento com escuro não excedeu a 48 horas / Abstract: Adventitious root initiation in the petioles of primary leaves of Phaseolus vulgaris L. cv. carioca propagate from parenchymatic cells of the phloem. The presence of the pulvinus inhibits rooting regardless of the age of the leaf. Young leaves without the pulvinus always produce roots, although in small numbers, while rooting of old leaves is less frequent but in larger number. Reduction of the leaf blade reduces rooting. In this respect upper half is more effective thus suggesting a hormonal effect besides the necessity of photosynthates produced in this area. Interruption of the main vein of the leaf induces rooting near the cut area except when apical. Such rooting does no affect rooting of the petiole. A carbohydrate requirement for rooting is suggested by the inhibitory effect of DCMU upon root formation. Dark pre-treatment of intact plants or isolated leaves for longer than 48h inhibits rooting. Although changes in chlorophyll levels were not detectable after this dark periodit is possible that the transfer from dark to light stimulated senescence and consequently restrained rooting. The pulvinus does not affect carbohydrate translocation although differences in the pattern of accumulation in leaves with and without pulvinus would suggest either a feed back control or a limited availability of these substances by the high levels of 'K IND. +¿ in the cells... Note: The complete abstract is available with the full electronic digital thesis or dissertations / Doutorado / Doutor em Biologia Vegetal

Soybean (Glycine max L. Merrill) is a new cash crop for north central and northwestern North Dakota producers. Soils and climate in these new soybean areas differ from those regions where the current fertilizer recommendations were based. Northcentral and northwestern North Dakota is more undulating, drier, cooler, and has differencing soils than eastern North Dakota and Minnesota. A three-year study to evaluate soybean best management practices was conducted during the 2016 to 2018 growing seasons. Each year, the study consisted of two sites and 12 treatments. By design, one site was on acidic (pH < 6) soil while the other was on alkaline (pH > 7.3) soil. Both site treatments were: untreated check, inoculated with rhizobia (B. japonicum L.), broadcast urea (55 kg ha-1), broadcast MAP (monoammonium phosphate, 11-52-0) (110 kg ha-1), in-furrow 10-34-0 (28 L ha-1), in-furrow 6-24-6 (28 L ha-1), foliar 3-18-18 (28 L ha-1) at V5 and R2 growth stages, and foliar 3-18-18 (28 L ha-1) with sulfate (1.1 kg ha-1) at V5 and R2. The acidic sites alone included two treatments of sugar beet (Beta vulgaris L.) waste lime (4.4 Mg ha-1 and 8.8 Mg ha-1). The alkaline sites alone received treatments of iron ortho-ortho-EDDHA (1.8% Fe) (7.1 L ha-1), and sodium (naked- without Fe) ortho-ortho-EDDHA (7.1 L ha-1). Treatments did not impact soybean yield, protein content or oil content at the 95% significance level. Sugar beet waste lime surface applied at planting at rates of 4.4 Mg ha-1 and 8.8 Mg ha-1 increased soil pH to a depth of 10 cm over the course of the growing season. / North Dakota Soybean Council

Although leaf movements have been documented for over a century, there are few studies focused on the adaptive significance of leaf movements, especially with experiments under controlled conditions. The major objective in this study is to determine the ecological significance of leaf movements in Rhododendron maximum, which is a subcanopy, evergreen species distributed in seasonally cold environments. Leaf movements could be necessary for maintaining a favorable energy balance and/or avoiding photoinhibition and photooxidation. A series of leaf manipulation treatments were established to verify these potential explanations. These leaf treatments were designed to separate the influence of leaf curling and leaf angle on leaf energy budget, gas-exchange characteristics, chlorophyll contents and leaf longevity. Leaf movements were found to have a significant influence on leaf physiology and longevity of R. maximum. Without changes in leaf angle, chlorophyll contents decreased, and permanent photoinhibition occurred due to excess irradiance absorption in the winter. Leaf angle also influenced leaf temperature although the changes in leaf temperature were within the physiological tolerances of R. maximum leaves. Leaf curing had little or no effect on the parameters measured in the study. / M.S.

The initial physiological processes leading to enhanced growth of loblolly pine subsequent to fertilization are not clearly understood. Much of the debate revolves around the temporal response of photosynthesis (Pn) to fertilization or even if Pn increases at all due to enhanced nutrition. This study tracked loblolly pine light-saturated photosynthesis (Asat), dark respiration (Rd), volume, height, basal diameter, and leaf area responses in eight clones to fertilization (112 kg/ha N) over the course of a growing season in the field. Measurements were conducted intensively before and after fertilization in order to track the initial physiological changes prior to any changes in growth in the fertilized seedlings. The results showed that fertilization does increase Pn rates although there was no significant effect on Rd rates during the study. The fertilized seedlings mean Asat rates were significantly higher on three sampling dates and remained higher throughout most of the sampling period. At the end of the growing season, the fertilized seedlings had a 30.5% higher projected crown area than the controls and 48% greater mean volumes. Physiological and growth responses were significantly different among clones with some showing large and others showing little or no response to fertilization. These results support the hypothesis from Gough et al. (2004b) that post-fertilization increases in Pn create extra photoassimilate used in building larger leaf areas. These larger leaf areas contribute to higher canopy photosynthesis levels, which leads to an increase in dry matter production. / Master of Science

O conhecimento sobre as formas de aplicação de Zn na adubação do pomar de laranjeiras, bem como a absorção, o transporte do Zn aplicado e a sua redistribuição interna, permitem um melhor manejo da adubação deste nutriente. A deficiência de Zn é encontrada com freqüência nos pomares citrícolas paulistas. Os objetivos foram: avaliar a absorção e o transporte de Zn aplicado nas folhas e no solo e a redistribuição interna do Zn em laranjeiras. Vários experimentos foram realizados em casa de vegetação, com laranjeira ´Valência` enxertadas em citrumeleiro Swingle. Nestes estudos foi utilizado adubo marcado com 65Zn. Assim, estudou-se a absorção foliar de Zn de diferentes fontes (ZnSO4.7H2O, ZnCl2, Zn-EDTA) e o seu transporte para os órgãos nascidos após a aplicação. A seguir, avaliou-se a contribuição da adubação foliar ao teor do Zn dos órgãos desenvolvidos após a aplicação e a parte do Zn aplicado nas folhas que é lavada para o solo por uma chuva simulada. A redistribuição interna do Zn nas laranjeiras também foi avaliada. As contribuições do Zn aplicado no sulco de plantio ou em cobertura para os órgãos que cresceram após a adubação também foram quantificadas. Avaliou-se a movimentação vertical do Zn aplicado em cobertura em Neossolo quartzarênico (NEO), contido em vaso. Foi avaliada a adsorção de Zn em diferentes tipos de solo do Estado de São Paulo. Conclui-se que a aplicação foliar aumentou o teor de Zn somente das folhas que receberam à aplicação foliar, sendo o ZnCl2 a fonte mais eficiente. Menos de 5% do total absorvido foi transportado para as brotações emitidas após a adubação, independente da fonte utilizada. Em comparação com o ZnCl2, a quelatização do Zn com EDTA diminuiu drasticamente a absorção foliar de Zn e não favoreceu o seu transporte para os órgãos novos. O Zn aplicado no solo, na cova de transplantio ou em cobertura, foi absorvido e contribuiu para aumentar o teor de Zn dos órgãos das brotações subseqüentes. O Zn, aplicado em cobertura em NEO, movimentou verticalmente, atingindo a profundidade de 20 cm em um ano. A adsorção de Zn foi maior quanto maiores foram a CTC e o pH dos solos, evidenciando a necessidade de se conhecer estes parâmetros para indicar a quantidade de Zn a ser aplicada na adubação. As laranjeiras redistribuíram 21% do Zn acumulado nas partes velhas para as partes novas / The knowledge on the methods of applying Zn in orange tree orchards, as well as the absorption, the transport of applied Zn and its redistribution within orange trees, allow a better management of fertilizer with this micronutrient. The Zn deficiency is common in the São Paulo State citrus orchards. The objectives were: to evaluate the absorption and the transport of Zn applied in the leaves and in the soil and the redistribution of Zn within the orange trees. Various experiments were carried out in greenhouse, with ´Valência` orange tree budded on Swingle citrumelo. In these studies, 65Zn labeled fertilizer was used. It was quantified the foliar absorption of Zn from different sources (ZnSO4.7H2O, ZnCl2, Zn-EDTA) and its transport to the organs grown after the application. The contribution of foliar fertilization to the Zn content of the organs developed after the application and the portion of Zn applied on leaves washed by a simulated rain were evaluated. The Zn redistribution within the orange trees was also evaluated. The contributions of Zn applied in the planting hole or on soil surface to the organ grown after the application were quantified. The vertical movement of Zn applied in the surface of Neossolo quartzarênico (NEO), contained in pots, was evaluated. The Zn adsorption in eight soil types of the São Paulo State was quantified. It was concluded that the foliar application increased the Zn content only in the leaves that received the foliar application, being ZnCl2 the most efficient source. Less than 5% of the total absorbed Zn was transported to the organs emitted after the fertilization, independently of the applied Zn source. Compared to the ZnCl2, the Zn EDTA chelating decreased drastically Zn absorption by the leaves and did not improve its transport to the new organs. Zinc applied to the soil in the transplanting hole or on surface was absorbed by roots and contributed to increase the organs Zn content of the new fluxes. Zinc applied in NEO surface moved vertically, until 20 cm depth, after one year. Higher CEC and pH of soil higher was Zn adsorption, evidencing the need of knowledge on these parameters to determine the amount of Zn to be applied in the soil. Around 21% of Zn accumulated in the old part of orange tree was redistributed to the new fluxes

Popularmente conhecidas como flowering stones ou ice plants, as plantas da família Aizoaceae (Caryophyllales) caracterizam-se por suas folhas suculentas morfologicamente diversas. Com centro de origem no sul da África, a maior parte das espécies pertence a subfamília Ruschioidaeae, com plantas de folhas dorsiventrais, cilíndricas e trígonas, sendo marcante a ocorrência de conação entre as bases de folhas opostas, e a presença de feixes vasculares periféricos, com xilema endoscópico. Nosso estudo mostra que a formação dos feixes vasculares periféricos é posterior ao estabelecimento da blastozona marginal, e que tecidos da face abaxial diferenciam-se no domínio adaxial da folha durante a histogênese da lâmina. Sugerimos que um mecanismo de abaxialização foliar esteja vinculado à formação da margem foliar de Aizoaceae. O xilema dos feixes vasculares periféricos é formado wide band tracheids - \"wbts\", um tipo especializado de elemento traqueal com acentuado espessamento da parede secundária. \"Wbts\" vinculam-se a órgãos suculentos e ocorrem somente em Aizoaceae, Anacampserotaceae e Cactaceae, tendo despertado interesse dos pesquisadores quanto à sua origem e função. A partir de análises comparativas de anatomia, ultraestrutura e de imunomarcação de pectina, concluímos que a definição de \"wbts\" deve ser mantida nas famílias, no entanto, destacamos a possível ocorrência de idioblastos traqueoidais na região de medular de algumas espécies. Este trabalho contribui no conhecimento da anatomia e ontogênese foliar de Aizoaceae, abrindo oportunidades de estudos sobre os mecanismos envolvidos no estabelecimento da dorsiventralidade em folhas de simetria radial. A análise comparativa de wide-band tracheids \"wbts\" em Aizoaceae, Anacampserotaceae e Cactaceae traz contribuições ao conhecimento sobre sua distribuição e características nos diferentes órgãos / Popularly known as flowering stones or ice plants, the species of Aizoaceae (Caryophyllales) are characterized by morphologically diverse succulent leaves. With center of origin in Southern Africa, most species are classified in the subfamily Ruschioidaeae, which present dorsiventral, cylindrical and three-angled leaved plants, being remarkable the occurrence of conation between the bases of opposite leaves, and the presence of peripheral vascular bundles with endoscopyc xylem. Our study shows that the formation of peripheral vascular bundles occurs after the marginal blastozone establishment, and abaxial tissues differentiate in the adaxial domain of the leaf, during blade histogenesis. We suggest that an abaxialization mechanism is involved in the formation of leaf margins in Aizoaceae. The xylem of peripheral vascular bundles is composed by wide band tracheids - wbts, a specialized type of cell that occurs only in Aizoaceae, Cactaceae Anacampserotaceae. The origin and function of this cell type has been the subject of study by some researchers. By means of comparative analysis of anatomy, ultrastructure and pectin immunolabeling, we conclude that the definition of \"wbts\" should be kept in the three families; however, we highlight the possibility of idioblasts tracheids in the some cases. This work contributes to the knowledge of leaf anatomy and ontogenesis in Aizoaceae, opening opportunities for studies on the mechanisms involved in the establishment of dorsiventrality in leaves with radial symmetry. A comparative analysis of wbts in Aizoaceae, Cactaceae Anacampserotaceae brings contributions to knowledge about their distribution and characteristics in different organs

A integridade das sociedades de insetos depende da capacidade dos indivíduos em discriminar aqueles que não pertencem às suas colônias; essas interações de reconhecimento são mediadas por hidrocarbonetos presentes na camada de cera da cutícula e atuam como mensageiros que codificam informação sobre o meio interno (colônia) e externo (ambiente). Os hidrocarbonetos são produzidos por células dérmicas e o perfil desses compostos recebe influência tanto de fontes endógenas quanto exógenas e isso o torna suscetível às mudanças temporais. A caracterização desses compostos em insetos-praga é importante, pois provêm subsídios tanto para pesquisa básica como para o manejo e controle de pragas. Nesse contexto, o presente estudo abordou as variações dos hidrocarbonetos cuticulares em relação às subcastas morfológicas das operárias (condição endógena) e utilização do substrato foliar (variável exógena) na formiga-cortadeira Atta sexdens, conhecida como uma das principais pragas herbívoras da região Neotropical. Os compostos foram extraídos em solvente apolar hexano e as amostras foram analisadas em sistema de cromatografia a gás acoplado à espectrometria de massas (CG-MS). Foram identificados 30 hidrocarbonetos com cadeia carbônica entre 19 e 40 átomos distribuídos em três classes de compostos, sendo a dos hidrocarbonetos ramificados a mais representativa, especificamente os trimetialcanos. Foram encontradas variações significativas para todas as variáveis analisadas, sugerindo que as subcastas possuem assinaturas químicas semelhantes quanto à diversidade de compostos, mas com grandes diferenças na proporção relativa dos mesmos. Em relação ao substrato foliar, colônias que tiveram acesso ao mesmo recurso apresentam uma composição química cuticular mais semelhante em relação àquelas que tiveram acesso a um recurso diferente. Complementarmente, os testes comportamentais mostraram que, na presença de uma coespecífica intrusa, as operárias residentes são muito mais agressivas em relação àquelas que utilizaram outro tipo de substrato foliar. / The integrity of insect societies relies on the ability of individuals to discriminate between nesmates from non-nestmates. These interactions are mediated by hydrocarbons spread all over the cuticle that act as messengers coding information about the colony and external environment. Cuticular hydrocarbons are produced by dermic cells and its composition is influenced by both endogenous and exogenous sources which makes them subject to temporal changes. Thus, this study approached the variations on this chemical profile in relation to the worker subcastes and type of foliar substrate used by leafcutter ant Atta sexdens, this species is known as one of the major neotropical herbivore pests and this kind of study is important because it can provide subsides in researches related to both basic biology as to pest control methods. The compounds were extracted using apolar solvent (hexane) and the samples were analyzed using gas chromatography - mass spectrometry technique (GC-MS). It was found 30 hydrocarbons which carbon chains varies between 19 and 40 atoms separated in three classes of compounds and the branched hydrocarbons as the most abundant one, especially the trimethyalcanes. The statistical analysis revealed significant differences on all the variables analyzed suggesting that subcastes possess similar chemical signatures as to the variety of compounds but with great differences in relative proportions thereof. Furthermore, the results show that foliar substrate has influence on the composition of cuticular hydrocarbons and concomitantly affect the interspecific recognition, thus colonies that had access to the same substrate has similar cuticular composition comparing to those who do not. Additionally, behavior tests showed that in the presence of a conspecific intruder the resident workers tend to be much more aggressive in relation to those who had fed on a different foliar substrate.

A determinação de macro- (N, P, K, Ca, Mg e S) e micronutrientes (Fe, Cu, Mn, Zn, B, Mo, Cl e Ni) em folhas de plantas é recomendada para avaliar o estado nutricional das culturas de interesse econômico. A análise convencional envolve a decomposição ácida do material vegetal, geralmente assistida por radiação micro-ondas, seguida da determinação dos elementos por ICP OES. Nesta tese, duas técnicas multielementares foram avaliadas para acessar o status nutricional da cultura da soja rapidamente: a espectrometria de emissão óptica com plasma induzido por laser (LIBS) e a espectrometria de fluorescência de raios X dispersiva em energia (EXDRF). Mapas microquímicos foram construídos empregando-se um sistema LIBS constituído por um laser de Nd:YAG (1064 nm, 5 ns, 360 mJ, 10 Hz) e um espectrômetro com óptica Echelle e detector ICCD, e um equipamento de bancada de micro-fluorescência de raios X dispersiva em energia (µ-EDXRF Orbis PC, EDAX) com tubo de Rh (50 kV, 50 W) e SDD. As distribuições elementares de Mg, Ca, P, S e K foram avaliadas, a fim de orientar e definir uma estratégia de amostragem para análise foliar direta da soja. Os mapas indicaram que a micro-heterogeneidade intrínseca dos elementos avaliados na amostra é significativa e há variações da composição foliar, tanto entre plantas de um mesmo tratamento, quanto entre folíolos de uma mesma planta. Esses fatores foram considerados críticos na definição de uma estratégia de amostragem única que pudesse abarcar e contornar os possíveis efeitos causados por esses fatores. Assim, definiu-se amostrar a maior área possível, sem privilegiar qualquer região específica da folha. Uma prova de conceito foi realizada, empregando-se LIBS para diagnose foliar de soja. Como as folhas secas de soja apresentaram baixa resistência mecânica, 30 folhas frescas de soja foram analisadas por LIBS, sendo acumulados 25 pulsos de laser por linha no modo de varredura, 12 linhas por folíolo e 3 folíolos por planta. Os resultados obtidos foram promissores em termos de comprovar a viabilidade técnica e prática do emprego de LIBS para análise direta de folhas frescas de soja. Análises de folhas frescas de soja também foram realizadas empregando-se um espectrômetro portátil de fluorescência de raios X dispersiva em energia (Tracer III-SD, Bruker) equipado com tubo de Rh (4W, 50 kV, 4,5 mm de diâmetro de feixe de raios X) e SDD. O status nutricional de plantas cultivadas sob condições controladas, com fornecimento adequado de nutrientes (tratamento controle) e com deficiência induzida de fósforo foi avaliado. Boas correlações foram obtidas para P (r = 0,838) e Zn (r = 0,888), que permitem inferir que a EDXRF pode ser recomendada para a quantificação desses nutrientes no campo. Os sinais detectados de Ca, Cu, Fe, K, Mn, P, S, Si, Zn e Rh (espalhamento Compton) permitiram a classificação das amostras em grupos utilizando análise de componentes principais (PCA). Os gráficos de scores e loadings da PCA mostraram: i) a separação entre os dois grupos de amostras (controle e deficientes em P), e ii) quais elementos foram responsáveis por esta separação. Dessa forma, a PCA constitui uma alternativa à análise quantitativa e pode ser utilizada em conjunto com EDXRF para identificar e classificar as amostras de soja como saudáveis ou deficientes em P. Assim, a partir dos resultados obtidos nesta tese, pode-se concluir que ambas as técnicas, LIBS e EDXRF, têm potencial para avaliar o estado nutricional da soja em tempo real, in situ e com mínimo tratamento de amostras. No entanto, para alcançar resultados quantitativos, diferentes estratégias de amostragem e calibração devem ser avaliadas criteriosamente a fim de superar os desafios aqui apresentados e criar condições de contorno para os inconvenientes que as folhas de soja apresentam como, por exemplo, a distribuição não-homogênea dos elementos e a baixa resistência mecânica quando secas / The determination of macro- (N, P, K, Ca, Mg and S) and micronutrients (Fe, Cu, Mn, Zn, B, Mo, Cl and Ni) in plant leaves is recommended to evaluate the nutritional status of crops of economic interest. Traditional analysis involves microwave-assisted acidic digestion the plant material, followed by determination of the elements by ICP OES. In this thesis, two multielemental techniques were evaluated to access the nutritional status of the soybean crop quickly: laser-induced breakdown spectroscopy (LIBS) and energy dispersive X-ray fluorescence spectrometry (EXDRF). Microchemical maps were built using a LIBS system constituted by a Q-switched Nd:YAG laser (1064 nm, 5 ns, 360 mJ, 10 Hz) and a spectrometer with Echelle optics and ICCD detector, and a benchtop micro-energy dispersive X-ray fluorescence spectrometer (?-EDXRF Orbis PC, EDAX) with Rh X-ray tube (50 kV, 50 W) and SDD. The elemental distributions of Mg, Ca, P, S and K were evaluated in order to guide and define a sampling strategy for direct analysis of soybean leaves. Maps indicated that intrinsic micro-heterogeneity of the elements evaluated in the sample is significant and there are variations in the leaf composition, between plants of the same treatment and between leaflets of the same plant. These factors were considered critical in defining a single sampling strategy that could encompass and circumvent the possible effects caused by them. Thus, it was decided to sample the largest possible area, without privileging any specific region of the leaf. A proof of concept was carried out using LIBS for foliar diagnosis of soybean. As the dry leaves of soybean presented low mechanical resistance, 30 fresh leaves of soybean were analyzed by LIBS, employing 25 laser pulses per line in the rastering mode, 12 lines per leaflet and 3 leaflets per plant. The obtained results were promising in order to prove technical and practical feasibility in using LIBS for direct analysis of fresh leaves of soybean. Analyzes of fresh leaves were also performed using a portable energy dispersive X-ray fluorescence spectrometer (Tracer III-SD, Bruker) equipped with Rh X-ray tube (4W, 50 kV, 4.5 mm diameter of X-ray beam) and SDD. The nutritional status of plants grown under controlled conditions, with good supply of nutrients (control treatment) and with phosphorus-induced deficiency were evaluated. Good correlations were obtained for P (r = 0.838) and Zn (r = 0.888), which allow to infer that EDXRF can be recommended for the quantification of these nutrients in the field. The detected signals of Ca, Cu, Fe, K, Mn, P, S, Si, Zn and Rh (Compton scattering) allowed the classification of samples into groups using Principal Component Analysis (PCA). The PCA scores and loadings graphs showed: i) the separation into two sample groups (control and P deficient), and ii) which elements were responsible for this separation. So, PCA constitutes an alternative method to quantitative analysis and it can be used with EDXRF in order to identify and classify soybean samples as healthy or P deficient. Thus, from the results obtained in this thesis, it can be concluded that both techniques, LIBS and EDXRF, have the potential to evaluate the nutritional status of soybean in real time, in situ and with minimal sample treatment. However, in order to achieve quantitative results, different sampling and calibration strategies should be carefully evaluated aiming to overcome the challenges presented here and circumvent the drawbacks of soybean leaves, such as the nonhomogeneous distribution of the elements and the low mechanical resistance when leaves are dried