título de Biólogo con mención en Medio Ambiente / El quimerismo ocurre cuando dos individuos genéticamente distintos y conspecíficos se fusionan o coalescen generando una única entidad genéticamente heterogénea conocida como quimera. Este aumento en la variabilidad genética intraorganismo supondría un aumento en la variabilidad fenotípica del mismo, lo que conferiría a estas entidades una mayor tolerancia ante cambios ambientales en comparación a individuos genéticamente homogéneos o no quiméricos, posiblemente debido a efectos sinérgicos entre las distintas líneas celulares. El beneficio de ser quimera ha sido estudiado en distintos grupos de algas, particularmente en especies de algas rojas (Gracilaria y Mazzaella), las cuales muestran una correlación positiva entre coalescencia y tolerancia al estrés. A pesar de ello, en macroalgas pardas los estudios han sido mayoritariamente descriptivos, evidenciado los procesos de formación de entidades quiméricas, así como la frecuencia del quimerismo en poblaciones naturales de Lessonia spicata. Sin embargo, se desconoce aún si en esta especie los organismos con quimerismo muestran mayor tolerancia al estrés que aquellos genéticamente homogéneos y si existe un efecto en la adecuación biológica de la quimera de acuerdo al número de individuos fusionados así como el nivel de parentesco de los individuos que se fusionan para formar la quimera (e.g. fusión entre hermanos, medios hermanos, vecinos, poblaciones distintas). Basado en lo anterior, el objetivo de este estudio fue evaluar la tolerancia a estrés por temperatura de plántulas quiméricas y unitarias de L. spicata cultivadas en condiciones contrastantes de temperatura, distinto número de individuos fusionados y nivel de parentesco. Para ello, primero se desarrolló un protocolo para la generación masiva de plántulas con variabilidad genética intraorganismo de L. spicata en laboratorio. Segundo, se evaluó la tolerancia al estrés en términos de la tasa de crecimiento en condiciones contrastantes de temperatura (12±2°C vs 18±2°C) de plántulas quiméricas con distinto número de individuos fusionados versus unitarias. Tercero, se evaluó el efecto del parentesco sobre la quimera y el estrés térmico, comparando crecimiento entre unitarias, quimeras conformadas por cepas locales y quimeras conformadas por cepas de distintas poblaciones. Los resultados indicaron que plántulas quiméricas provenientes de la fusión de 5 esporofitos poseen una mayor tasa de crecimiento que las plántulas unitarias en condiciones normales de temperatura (12°C). Mientras que a estrés 10 térmico (18ªC) plántulas quiméricas también poseen una mayor tasa de crecimiento, pero la significancia de la respuesta depende de la densidad y parentesco de las entidades que forman la quimera. En términos de parentesco, los resultados sugieren que las quimeras provenientes de la fusión de esporofitos de plantas no emparentadas poseen una tasa de crecimiento mayor que quimeras formadas con medios hermanos. A la luz de estos resultados es posible concluir que el quimerismo en la macroalga parda Lessonia spicata le conferiría una ventaja a dichos organismos frente a los continuos cambios ambientales. Este hecho adquiere relevancia si se sabe que la especie está constantemente expuesta a cambios de la temperatura producto del Niño, así como el aumento de la temperatura del océano causado por cambio climático. / Chimerism occurs when two genetically distinct and conspecific individuals fuse or coalesce, generating a single entity genetically heterogeneous known as chimera. This condition increase the intraorganismal genetic variability, that could increase in the phenotypic variability and provide higher tolerance to environmental changes compared to genetically homogeneous or non-chimeric individuals. These can be produced due to synergistic effects between the genetically different cell lines that coexist into the chimera. The benefit of chimeric condition has been studied in different groups of macroalgae, particularly in the red species (Gracilaria and Mazzaella). They show a positive correlation between coalescence and stress tolerance. Despite of this, in the brown macroalgae the studies have been poorly described, most of them are descriptive, evidencing the formation processes of chimeric entities, as well as the frequency of chimerism in natural Lessonia spicata populations. However, it is still unknown whether the chimerism in Lessonia species shows greater stress tolerance than those genetically homogeneous. As well as whether there the fitness is affected by to the number of individuals fused, and/or the level of kinship among the individuals that composed the chimera (e.g. fusion between siblings, half siblings, neighbors, different populations). In this context, the main objective of this study was evaluate the thermal stress tolerance of chimeric and unitary organism in the brown macroalgae L. spicata, which were cultivated under contrasting temperature conditions, different number of fused individuals and level of kinship. To this, firstly in this study generated a protocol for massive generation of plantlets with intraorganismal genetic variability of L. spicata in laboratory. Secondly, the stress tolerance was evaluated in terms of specific growth rate under contrasting temperature conditions (12 ± 2 °C vs 18 ± 2 °C) of chimeric plantlets with different numbers of individuals fused versus unitary ones. Thirdly, the effect of kinship on the chimera and thermal stress was evaluated by comparing growth rate between unitary individuals versus chimeras formed by local strains, and from different populations. The results indicate that chimeric plantlets resulting from the fusion of 5 sporophytes have a higher growth rate than the unitary plantlets under normal conditions (12°C). While under thermal stress (18°C) the chimeras have the higher growth rate. However, the significant differences depended on the density and kinship of the entities that made up the chimera and the culture temperature. In terms of 12 kinship, the results suggest that chimeras resulting from the fusion of sporophytes of unrelated plants have a higher growth rate than chimeras formed by half-sib brothers. Follow these results, it is possible to conclude that chimerism in the brown macroalga Lessonia spicata would confer an advantage to these organisms in face to continuous environmental changes. This fact acquires relevance if it is known that this species is constantly exposed to temperature changes produced by ENSO events, as well as the increase in the ocean temperature caused by climate change.

Svetimžemiais vadinami iš kitų kraštų kilę ir dėl žmonių veiklos į teritorijas, kuriose jie anksčiau neaugo, patekę augalai. Vienas iš tokių adventyvinių augalų yra varpinė medlieva (Amelanchier spicata) Taigi adventyvinių augalų skverbimasis yra nenutrūkstantis, su žmogaus veikla susijęs procesas, todėl galima teigti, jog tokių augalų šalyje ir toliau daugės. Varpinės medlievos (Amelanchier spicata) tyrimai buvo atliekami 2007-2008 m. liepos – rugsėjo mėn. keturiose skirtingose vietovėse, t.y. Antaviliuose, Aukštuosiuose Paneriuose, Žemojoje Veržuvoje ir Antakalnyje. Kiekvienoje vietovėje buvo pasirinktas 10000 m2 plotas. Plotas suskirstytas į 16 laukelių, o vienas laukelis sudarė 625 m2. Šiose vietovėse vertinant antžeminių dalių morfologinius parametrus buvo matuojamas stiebų aukštis, aukštis iki pirmos šakos, skersmuo, nustatomas stiebų brandos amžius bei absoliutus amžius. Tyrimų metu nustatyta, kad tankiausia buvo Antavilių populiacija. Pagal brandos amžiaus grupes visose tirtose populiacijose vyravo vegetatyviniai stiebai. Pagal morfologinius stiebų požymius visos keturios populiacijos skiriasi nedaug. Pagal absoliutųjį amžių daugiausia populiacijose buvo rasta antrų, trečių ir ketvirtų metų amžiaus stiebų, o mažiausiai septyniolikos, aštuoniolikos, devyniolikos ir dvidešimties metų amžiaus stiebų. Tirtose populiacijose morfologinių požymių kitimai priklauso tiek nuo amžiaus, tiek nuo populiacijos tankumo, tiek nuo konkurencijos bei skirtingų aplinkos sąlygų buveinėse... [toliau žr. visą tekstą] / Exotic are the plants originating from the lands and coming due to the human activity to the areas where they never grow before. One of these adventive plants is thicket shadbush (Amelanchier spicata). So, penetration of adventive plants is a continuous process associated with human activities, therefore it can be argued that the number of such plants in the country will continue to grow. Research of thicket shadbush (Amelanchier spicata) was carried out in July - September 2007-2008 in four different areas, namely Antaviliai, Aukštieji Paneriai, Žemoji Veržuva and Antakalnis. The area of 10000 m2 was chosen in each location. The area was then divided into 16 squares, and one square constituted 625 m2. When evaluating the morphological parameters of the ground parts of the plants, the height of stalks, the height to the first branch, the diameter was measured, and the absolute age and maturity age of stalks was determined. It was determined during the research that the densest was Antaviliai population. According to the maturity age groups the vegetative stalks were dominating in all analysed populations. According to morphological stalk features all for populations differ very little. By absolute age, the highest number of plants in the populations was with the second, third and fourth year stalks, and the least number was with stalks of seventeen, eighteen, nineteen and twenty year old. Changes of morphological features in analysed populations depend on age, on the density... [to full text]

Global climate change is a real-time problem that presents threats to many species. Climate change can alter ecosystems and may lead to species extinction. Species can respond to climate change by moving to a better environment or adapting. Therefore, it is necessary to rely on several approaches and perspectives to anticipate ecological impacts of climate change. A common strategy uses models to understand how populations respond to different climate scenarios. Ecological models have helped usunderstand population persistence, but they often ignore how populations adapt to environmental stress. Adaptive evolution has been ignored because it was assumed that evolution was too slow to have any effect on ecology. Current research has shown that some populations are able to rapidly adapt to novel environments and this is essential for population persistence. We used a population genomics approach to understand how different precipitation regimes affect the perennial bunchgrass, Pseudoroegneria spicata, in the eastern Idaho sagebrush steppe. Our objective was to determine how genetic diversity changes under manipulated precipitation regimes and whether these changes were consistent with patterns of genetic diversity under natural precipitation regimes. The manipulated precipitation regimes consist of three precipitation treatments: control, drought with 50% ambient precipitation, and irrigation with 150% ambient precipitation. The natural precipitation regimes consist of two treatments: low elevation (drier than the experimental site) and high elevation (wetter). We collected plant tissue to isolate plant DNA and then used sequenced DNA for analyses. We used a hierarchical Bayesian model to estimate genotypes and allele frequencies across all loci. We found that there were low levels of genetic variation across all experimental precipitation treatments. When examining genetic differentiation, we found there was stronger differentiation in the natural precipitation regimes. Our study focuses on the short-term responses to climate to understand how environmental stress influences genetic diversity.

With many natural landscapes undergoing restoration efforts, there is a growing need for the optimization of direct seeding practices. Seeds planted on wildlands are often consumed by rodents leading to reduced plant establishment. Coating seeds in rodent aversive products may prevent seed predation. We tested ten seed-coating formulations containing products expected to deter rodents, namely: ghost and cayenne pepper powders; essential oils from bergamot, neem, and pine; methyl-nonyl-ketone, anthraquinone, activated carbon, beta-cyclodextrin and a blank coating containing no rodent deterrents to serve as a control treatment. Each treatment was applied to Pseudoroegneria spicata (bluebunch wheatgrass) seeds. These seeds germinated similarly to uncoated control seeds unless the coating contained methyl-nonyl-ketone which reduced germination. Seeds were offered to Ord's kangaroo rats (Dipodomys ordii) that strongly avoided the treatments in favor of uncoated control seeds. Notably, the blank coating, lacking active ingredients, still elicited 99% avoidance. However, these results indicated behavior when alternative food sources are readily available, a scenario rare in nature. To address this, a second feeding experiment was conducted to observe D. ordii's behavior under calorie-restricted conditions. D. ordii were subjected to a fast period and then offered only one treatment. Under these conditions, many subjects chose to consume coated seeds, but to a lesser degree than subjects offered control seeds. Seeds coated in ghost pepper, neem oil, and activated carbon reduced consumption by 47-50%. Given these lab results, we would expect these seed-coatings to increase the establishment of native seeds following the direct seeding of wildlands by deterring rodent seed-predation.

Contributing to the success of Bromus tectorum in the Intermountain West may be a mechanism called apparent competition, which occurs when one species increases the pressure of a consumer on a second species. This indirect interaction has been documented only a few times in invasive plant systems, and never in a fungal pathosystem. We examined the effects of the invasive annual Bromus tectorum and predation by the seed pathogen Pyrenophora semeniperda on seedling emergence and survival for two native grasses (Pseudoroegneria spicata and Elymus elymoides), by manipulating B. tectorum densities and P. semeniperda inoculum loads in randomized plots. Identical field studies were conducted in Skull Valley, Utah (xeric site) and Sprague, Washington (mesic site). The addition of inoculum decreased emergence of native grass seedlings at both sites and increased the amount of unemerged native seeds that were killed by P. semeniperda. Higher densities of B. tectorum decreased native grass survival at the mesic site and increased survival at the xeric site probably due to the beneficial effects of B. tectorum litter on soil moisture. At both sites, there were more B. tectorum seeds found in the seed banks in plots with high B. tectorum densities than in low-density plots. This indicates an increase in available prey for P. semeniperda. There was a much lower level of infection in B. tectorum seed bank seeds at the mesic site than at the xeric site. The high level of ungerminated native seeds killed by background levels of P. semeniperda, combined with the increase in available prey for the fungus in high-density B. tectorum plots, shows that apparent competition may play a role, along with direct competition, in the success of B. tectorum. This interaction is important to consider when dealing with control of B. tectorum.

Made available in DSpace on 2017-07-10T17:59:30Z (GMT). No. of bitstreams: 1 Ana Claudia Cabral dos Santos.pdf: 1804875 bytes, checksum: 59accd259357d955c055e44645dee662 (MD5) Previous issue date: 2014-12-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Biodiesel is a fuel that can be obtained from renewable sources and due to its chemical composition is sensitive to oxidation. To increase their oxidative stability is necessary to add antioxidants, which are compounds capable of avoiding or delaying oxidation reactions and can be synthetic or natural, from the natural, we highlight a variety of plants with antioxidant activity, among them the mint (Mentha spicata L.) and Acerola (Malpighia glabra L.). The objective of this study was to evaluate the oxidative stability of biodiesel in the presence of natural antioxidants from extracts of Acerola and mint leaves obtained by conventional extraction and supercritical CO2 on temperature and various pressure using oxidative stability in Rancimat test, avaliou- is also the synthetic antioxidant TBHQ, to compare the results obtained with the use of the plant extracts. The effects of temperature and pressure on the yield and quality of the extract. The best induction times were obtained for biodiesel plus the supercritical extracts of Acerola 40 °C and 150 bar condition (1.38 h) and 60 °C and 250 bar (1.07 h) and the supercritical extract of mint conditions of 40 °C and 150 bar (1.08 h), 40 °C and 250 bar (1.71 h) and 60 °C and 250 bar (2.04 h) and soxhlet extract with hexane obtained from both acerola (2.84 h) and Mint (2.87 h), which showed greater induction time of the control (1.04 h). Biodiesel plus the synthetic antioxidant TBHQ got time higher induction to control and biodiesel plus extracts and from 36.95 hours. The oxidative stability of biodiesel was more increased when the extracts obtained by conventional extraction using Hexane as the solvent, which can be extracted from a larger quantity of compounds with antioxidant activity. / Biodiesel é um combustível que pode ser obtido de fontes renováveis e devido sua composição química é sensível à oxidação. Para aumentar sua estabilidade oxidativa é necessário acrescentar antioxidantes, que são compostos capazes de evitar ou retardar reações de oxidação e podem ser sintéticos ou naturais, dentre os naturais, destacam-se uma variedade de plantas com atividade antioxidante, dentre elas a Hortelã (Mentha spicata L.) e Acerola (Malpighia glabra L.). O objetivo deste trabalho foi avaliar a estabilidade oxidativa do Biodiesel na presença de antioxidantes naturais dos extratos das folhas de Acerola e Hortelã obtidos por extração convencional e com CO2 supercrítico em condições de temperatura e pressão variadas, utilizando teste de estabilidade oxidativa em Rancimat, avaliou-se, também, o antioxidante sintético TBHQ, para comparar com os resultados obtidos com a utilização dos extratos das plantas. Foram avaliados os efeitos da temperatura e Pressão no rendimento e da qualidade do extrato. Os melhores tempos de indução obtidos foram para o Biodiesel acrescido dos extratos supercríticos da Acerola nas condições 40 °C e 150 bar (1,38 h) e 60 °C e 250 bar (1,07 h) e os extratos supercríticos da Hortelã nas condições de 40 °C e 150 bar (1,08 h), 40 °C e 250 bar (1,71 h) e 60 °C e 250 bar (2,04 h) e os extratos soxhlet obtidos com hexano, tanto da Acerola (2,84 h) quanto da Hortelã (2,87 h), que apresentaram tempo de indução maior que o controle (1,04 h). O Biodiesel acrescido do antioxidante sintético TBHQ obteve tempo de indução superior ao controle e ao biodiesel acrescidos dos extratos, sendo de 36,95 horas. A estabilidade oxidativa do Biodiesel foi superior quando acrescido dos extratos obtidos por extração convencional utilizando Hexano como solvente, que, pode ter extraído uma maior quantidade de compostos com atividade antioxidante.

Neste trabalho foi verificada a eficiência da HS-SPME associada à GC/qMS como ferramenta capaz de detectar alterações no perfil de compostos voláteis de Schinus polygamus e Baccharis spicata. Estas alterações são provocadas por insetos herbívoros (cecidógenos) que utilizam as folhas destas plantas como local para se alimentarem e se reproduzirem e, como conseqüência, produzem alterações no tecido vegetal (galhas). Para este propósito foi usado, como fase extratora, o filme polimérico DVB-CAR-PDMS, que apresenta alta capacidade de extração. Na S. polygamus, tanto folhas sadias, como galhas apresentaram grande quantidade de n-heptano (> 38,2 %) e n-nonano (> 24,4 %), sendo que este não foi detectado no óleo hidrodestilado de folhas da mesma amostra. Nas galhas também foi constatada a presença de alguns mono- e sesquiterpenos não detectados nas folhas, sendo o a-pineno (17,6 %), um dos compostos majoritários. Foi também observado um acréscimo significativo na concentração do limoneno. Os compostos majoritários no headspace das folhas de B. spicata foram: 1-undeceno (17,8 %), limoneno (15,3 %), b-pineno (13,5 %), (E)-cariofileno (12,8 %) e g-muroleno (11,4 %), enquanto que nas galhas, os compostos majoritários foram o a-pineno (40,9 %) e o limoneno (19,1 %). O 1-undeceno não foi detectado no óleo hidrodestilado de folhas desta planta, enquanto que o espatulenol foi o composto majoritário deste óleo (34,3%), encontrando-se em baixas concentrações nos voláteis extraídos por HS-SPME. As diferenças constatadas na composição dos VOC de folhas e galhas nas espécies S. polygamus e B. spicata podem ser um fator indicativo de que a presença do cecidógeno estimula a biossíntese de alguns compostos, que podem apresentar algum tipo de função infoquímica. Evidências de diferenças qualitativas entre o óleo hidrodestilado das folhas sadias e o perfil dos compostos voláteis do headspace das mesmas também são um indicativo de que o emprego de temperaturas amenas na HS-SPME propicia a obtenção de um perfil de compostos voláteis mais próximo daquele da planta in vivo. O acesso a estas diferenças (qualitativas e quantitativas) só foi possível através do emprego da HS-SPME, o que evidencia o potencial desta técnica como ferramenta investigativa para compostos infoquímicos, abrindo horizontes para futuras pesquisas. / HS-SPME coupled to GC/qMS was employed in this work as an efficient tool to verify differences in the volatile compounds composition of Schinus polygamus and Baccharis spicata leaves and galls. Plant volatile composition may be changed when herbivore insects (cecidógenos) use leaves as a site for reproduction and for feeding purposes. The action of those insects may resulting changes in plant tissue, which are called galls. The triple layer DVB-CAR-PDMS fiber was employed as sorbing phase, in order to achieve high efficiency in the extraction process. Galled and ungalled S. polygamus leaves presented high amount of n-heptane (> 38,2 %) and n-nonane (> 24,4 %), while n-heptane was not detected in the hydrodistilled oil of leaves of the same sample. The presence of a-pinene was observed only in galls, along with some other mono- and sesquiterpenes. Also, the amount of limonene was higher in galls than in ungalled leaves. Major compounds in the headspace of B. spicata leaves were: 1-undecene (17,8 %), limonene (15,3 %), b-pinene (13,5 %), (E)-caryophyllene (12,8 %) e g-muurolene (11,4 %), while in galls a-pinene (40,9 %) and limonene (19,1 %) were present in higher concentrations. One-undecene was not detected in the hydrodistilled oil of the leaves of this plant and spathulenol was the major compound of this oil (34,3%), being present in low concentrations in the chromatographic profile of HS-SPME. Differences found in the VOC composition of galls and ungalled leaves of S. polygamus e B. spicata may be an evidence of the cecidogene presence, which might stimulate the biosynthesis of some infochemical compounds. Qualitative differences between hydrodistilled oil and headspace chromatographic profile of the same sample indicates that HS-SPME mild temperatures provide a volatile compounds profile closer to that of in vivo plant. Approaching qualitative and quantitative differences in plant volatile compounds profile was made possible only through the use of HS-SPME. This fact highlights the potential of this technique as a research tool for infochemical compounds studies, and opens new horizons for future investigations of distinct plants.

Neste trabalho foi verificada a eficiência da HS-SPME associada à GC/qMS como ferramenta capaz de detectar alterações no perfil de compostos voláteis de Schinus polygamus e Baccharis spicata. Estas alterações são provocadas por insetos herbívoros (cecidógenos) que utilizam as folhas destas plantas como local para se alimentarem e se reproduzirem e, como conseqüência, produzem alterações no tecido vegetal (galhas). Para este propósito foi usado, como fase extratora, o filme polimérico DVB-CAR-PDMS, que apresenta alta capacidade de extração. Na S. polygamus, tanto folhas sadias, como galhas apresentaram grande quantidade de n-heptano (> 38,2 %) e n-nonano (> 24,4 %), sendo que este não foi detectado no óleo hidrodestilado de folhas da mesma amostra. Nas galhas também foi constatada a presença de alguns mono- e sesquiterpenos não detectados nas folhas, sendo o a-pineno (17,6 %), um dos compostos majoritários. Foi também observado um acréscimo significativo na concentração do limoneno. Os compostos majoritários no headspace das folhas de B. spicata foram: 1-undeceno (17,8 %), limoneno (15,3 %), b-pineno (13,5 %), (E)-cariofileno (12,8 %) e g-muroleno (11,4 %), enquanto que nas galhas, os compostos majoritários foram o a-pineno (40,9 %) e o limoneno (19,1 %). O 1-undeceno não foi detectado no óleo hidrodestilado de folhas desta planta, enquanto que o espatulenol foi o composto majoritário deste óleo (34,3%), encontrando-se em baixas concentrações nos voláteis extraídos por HS-SPME. As diferenças constatadas na composição dos VOC de folhas e galhas nas espécies S. polygamus e B. spicata podem ser um fator indicativo de que a presença do cecidógeno estimula a biossíntese de alguns compostos, que podem apresentar algum tipo de função infoquímica. Evidências de diferenças qualitativas entre o óleo hidrodestilado das folhas sadias e o perfil dos compostos voláteis do headspace das mesmas também são um indicativo de que o emprego de temperaturas amenas na HS-SPME propicia a obtenção de um perfil de compostos voláteis mais próximo daquele da planta in vivo. O acesso a estas diferenças (qualitativas e quantitativas) só foi possível através do emprego da HS-SPME, o que evidencia o potencial desta técnica como ferramenta investigativa para compostos infoquímicos, abrindo horizontes para futuras pesquisas. / HS-SPME coupled to GC/qMS was employed in this work as an efficient tool to verify differences in the volatile compounds composition of Schinus polygamus and Baccharis spicata leaves and galls. Plant volatile composition may be changed when herbivore insects (cecidógenos) use leaves as a site for reproduction and for feeding purposes. The action of those insects may resulting changes in plant tissue, which are called galls. The triple layer DVB-CAR-PDMS fiber was employed as sorbing phase, in order to achieve high efficiency in the extraction process. Galled and ungalled S. polygamus leaves presented high amount of n-heptane (> 38,2 %) and n-nonane (> 24,4 %), while n-heptane was not detected in the hydrodistilled oil of leaves of the same sample. The presence of a-pinene was observed only in galls, along with some other mono- and sesquiterpenes. Also, the amount of limonene was higher in galls than in ungalled leaves. Major compounds in the headspace of B. spicata leaves were: 1-undecene (17,8 %), limonene (15,3 %), b-pinene (13,5 %), (E)-caryophyllene (12,8 %) e g-muurolene (11,4 %), while in galls a-pinene (40,9 %) and limonene (19,1 %) were present in higher concentrations. One-undecene was not detected in the hydrodistilled oil of the leaves of this plant and spathulenol was the major compound of this oil (34,3%), being present in low concentrations in the chromatographic profile of HS-SPME. Differences found in the VOC composition of galls and ungalled leaves of S. polygamus e B. spicata may be an evidence of the cecidogene presence, which might stimulate the biosynthesis of some infochemical compounds. Qualitative differences between hydrodistilled oil and headspace chromatographic profile of the same sample indicates that HS-SPME mild temperatures provide a volatile compounds profile closer to that of in vivo plant. Approaching qualitative and quantitative differences in plant volatile compounds profile was made possible only through the use of HS-SPME. This fact highlights the potential of this technique as a research tool for infochemical compounds studies, and opens new horizons for future investigations of distinct plants.

Neste trabalho foi verificada a eficiência da HS-SPME associada à GC/qMS como ferramenta capaz de detectar alterações no perfil de compostos voláteis de Schinus polygamus e Baccharis spicata. Estas alterações são provocadas por insetos herbívoros (cecidógenos) que utilizam as folhas destas plantas como local para se alimentarem e se reproduzirem e, como conseqüência, produzem alterações no tecido vegetal (galhas). Para este propósito foi usado, como fase extratora, o filme polimérico DVB-CAR-PDMS, que apresenta alta capacidade de extração. Na S. polygamus, tanto folhas sadias, como galhas apresentaram grande quantidade de n-heptano (> 38,2 %) e n-nonano (> 24,4 %), sendo que este não foi detectado no óleo hidrodestilado de folhas da mesma amostra. Nas galhas também foi constatada a presença de alguns mono- e sesquiterpenos não detectados nas folhas, sendo o a-pineno (17,6 %), um dos compostos majoritários. Foi também observado um acréscimo significativo na concentração do limoneno. Os compostos majoritários no headspace das folhas de B. spicata foram: 1-undeceno (17,8 %), limoneno (15,3 %), b-pineno (13,5 %), (E)-cariofileno (12,8 %) e g-muroleno (11,4 %), enquanto que nas galhas, os compostos majoritários foram o a-pineno (40,9 %) e o limoneno (19,1 %). O 1-undeceno não foi detectado no óleo hidrodestilado de folhas desta planta, enquanto que o espatulenol foi o composto majoritário deste óleo (34,3%), encontrando-se em baixas concentrações nos voláteis extraídos por HS-SPME. As diferenças constatadas na composição dos VOC de folhas e galhas nas espécies S. polygamus e B. spicata podem ser um fator indicativo de que a presença do cecidógeno estimula a biossíntese de alguns compostos, que podem apresentar algum tipo de função infoquímica. Evidências de diferenças qualitativas entre o óleo hidrodestilado das folhas sadias e o perfil dos compostos voláteis do headspace das mesmas também são um indicativo de que o emprego de temperaturas amenas na HS-SPME propicia a obtenção de um perfil de compostos voláteis mais próximo daquele da planta in vivo. O acesso a estas diferenças (qualitativas e quantitativas) só foi possível através do emprego da HS-SPME, o que evidencia o potencial desta técnica como ferramenta investigativa para compostos infoquímicos, abrindo horizontes para futuras pesquisas. / HS-SPME coupled to GC/qMS was employed in this work as an efficient tool to verify differences in the volatile compounds composition of Schinus polygamus and Baccharis spicata leaves and galls. Plant volatile composition may be changed when herbivore insects (cecidógenos) use leaves as a site for reproduction and for feeding purposes. The action of those insects may resulting changes in plant tissue, which are called galls. The triple layer DVB-CAR-PDMS fiber was employed as sorbing phase, in order to achieve high efficiency in the extraction process. Galled and ungalled S. polygamus leaves presented high amount of n-heptane (> 38,2 %) and n-nonane (> 24,4 %), while n-heptane was not detected in the hydrodistilled oil of leaves of the same sample. The presence of a-pinene was observed only in galls, along with some other mono- and sesquiterpenes. Also, the amount of limonene was higher in galls than in ungalled leaves. Major compounds in the headspace of B. spicata leaves were: 1-undecene (17,8 %), limonene (15,3 %), b-pinene (13,5 %), (E)-caryophyllene (12,8 %) e g-muurolene (11,4 %), while in galls a-pinene (40,9 %) and limonene (19,1 %) were present in higher concentrations. One-undecene was not detected in the hydrodistilled oil of the leaves of this plant and spathulenol was the major compound of this oil (34,3%), being present in low concentrations in the chromatographic profile of HS-SPME. Differences found in the VOC composition of galls and ungalled leaves of S. polygamus e B. spicata may be an evidence of the cecidogene presence, which might stimulate the biosynthesis of some infochemical compounds. Qualitative differences between hydrodistilled oil and headspace chromatographic profile of the same sample indicates that HS-SPME mild temperatures provide a volatile compounds profile closer to that of in vivo plant. Approaching qualitative and quantitative differences in plant volatile compounds profile was made possible only through the use of HS-SPME. This fact highlights the potential of this technique as a research tool for infochemical compounds studies, and opens new horizons for future investigations of distinct plants.

The diploma thesis deals with content substances with antioxidant effects in green spice. In the literary part, green spices, antioxidants are defined, and lesser known species are introduced, as well as the determination methods used in the practical part. In the practical part are given the individual determinations. The DPPH method was used to determine the antioxidant capacity, to determine the nitrate content ISE method was used, the flavonoids were determined using the Folin-Ciocalteaue reagent, and the standard in the phenols was gallic acid. Vitamin C was determined by liquid chromatography.