Species interactions are recognised as an important evolutionary process, with foundation species in particular being of exceptional importance. Foundation species are those species exhibiting dynamic physical traits, under strong genetic control, that shape the natural processes of habitats and ecosystems. These traits lead to extended consequences for the associated organisms in their community. Therefore, intra-specific variation of a foundation species can have important evolutionary consequences for habitats, communities and entire ecosystems. One such foundation species is aspen (Populus tremula L.), which has important conservation value, particularly for the high diversity of associated species. In Scotland aspen exists in fragmented clonal patches, but has been found to contain a high diversity of associated organisms some of which have a UK Biodiversity Action Plan (BAP). One such group of organisms of high diversity and conservation value in Scotland are the epiphytic cryptogams (i.e. mosses, liverworts, lichens). To date more than 300 species have been recorded on aspen in Scotland, comprising approximately 40% of the epiphyte flora of Europe. The research presented here uses a combination of natural aspen system and two aspen common gardens to test the effects of aspen genetic diversity on physical traits potentially important for epiphyte diversity. The traits investigated were bark texture and bark phenolic chemistry. Bark texture in the wild clones was found vary significantly between clones and under strong genetic control (up to 40%). Bark phenolic chemistry also showed significant genotypic variation, but could not be correlated with patterns of epiphyte species richness and diversity. Nevertheless, epiphytes showed significant patterns related to aspen genotype, particularly along a gradient of bark texture. The results indicate that epiphyte communities are part of the ‘extended phenotype’ of native aspen populations in Scotland are very important for maintaining current levels of epiphyte diversity. A greater diversity and abundance of aspen genotypes in the landscape are essential for increasing epiphyte species richness and diversity, and for ecosystem health as a whole.

This study refers to developed ecological model abroad, and established the seagrass model with MATLAB compiler. I also took the seagrass meadows in south Taiwan-Nanwan for my studying case, and simulated the dynamic effect of seagrass and epiphyte biomass, as well as nutrient, and attempted to go on probing into the cause with northeast monsoon and typhoon. The simulating site of this study was Nanwan, which is located at Hengchun Peninsula, the southern tip of Taiwan. The dominant species in this area is Thalassia hemprichii. South Taiwan is situated at a tropical climate, and the variation of air temperature is small. Additionally, Kurshio embranchment cause the variation of water temperature smaller, about 24 (¢J) to 30 (¢J).The northeastern monsoonal winds, formed downhill winds, are extremely forceful from October to April, so the wind speed is greater during this period than the rest of the year. In South Taiwan, dry-wet season is clearly. The dry season is from November to April, and the wet season is from May to October. The main rainfall comes from southwest monsoon, especially summer typhoon (June to September). The wind speed is raised abruptly by typhoon and makes water agitate, which not only cause the mortality raising but also the sediment turbulence. By Lin¡¦s research (2005), the growing area of seagrass meadow in Nanwan is a half-closed tidal pool where human makes huge effect and there is a lot of drainage of house and inn sewage. Furthermore, these seagrasses in Nanwan would be exposed to air during the period of poor tide and the emerged period is the longest of these three areas -Nanwan, Dakwan and Wanliton. The seasonal dynamic of seagrass, which is located in the high site of intertidal zone, is obvious, and the biomass is larger in summer than in winter; but that is not obvious in the low site and tidal pool. By the seasonal condition and some specially climate condition mentioned above, the analysis of simulate cases would be go on. Comparing of the modeling result and real measurement, the seasonal changing situation mostly match up. No matter high site (emerged and dried) or low site, there is the maximum of seagrass biomass (including above ground, below ground, or shoot density) in summer, and the minimum in winter. Typhoon causes the biomass losing abruptly in summer. R/S ratio (below-ground biomass division above-ground biomass) is bigger in winter than in summer. On one hand the inside nitrogen redistribution is larger in summer, because the larger growth rate occurs in summer, and the more nutrient is supplied from roots, on the other the redistribution is smaller in winter cause the less nutrient is supplied from roots. Epiphyte biomass has the maximum in summer, when the nutrient concentration of water is larger. In the section of the difference between low and high site seagrass, it is apparent that the high site seagrass would be exposed to air and dried by northeast monsoon. Although typhoon comes up, its influence is not so strong as northeast monsoon at high site. The maximum biomass still occurs in summer, and it is presumed that the living environment of high site seagrass is with more pressure by nature. The above-ground biomass of high site seagrass is smaller than low site, but the below-ground biomass is much lager at high site. Besides, shoot density is larger at high site. The biomass of epiphyte is larger at low site just opposite to shoot density. It is supposed that high site seagrass is emerged to air and limited by environment factors so above-ground biomass would be reduced and store up the sustenance to below-ground biomass. It is conjectured that the main factor with shoot density is affected by light density and below-ground biomass. In shallow water, the seagrass at high site could accept more light energy, moreover the below-ground biomass is sufficient and the recruitment rate is large, thus there are more shoots at high site. Epiphytes are also limited by water depth and wind, and the biomass of epiphyte at high site is smaller than at low site.

The goal of this study was to assess the epiphytic diatom community structure of two host species along a karst gradient in the upper Green River, Kentucky to a gain a better understanding of the role of diatoms in the food web. The host species studied were Podostemum ceratophyllum and Cladophora. Percent cover of P. ceratophyllum and Cladophora were quantified in the four study reaches. The host species were sampled near-shore and mid-channel in each reach in September and October of 2013. After diatoms were extracted from the host and enumerated the density and diversity were quantified. Twelve genera were identified with > 91% of the community in each reach being Cocconeis. The second most abundant genus was Achnanthes or Navicula depending on the reach. The density and diversity of diatoms increased longitudinally going downstream. Exceptions to this trend occurred when high flow events disturbed the community. Within reaches there were no differences in diatom diversity in near-shore and mid-channel habitats. Diatom density in near-shore and mid-channel habitats was only different in the most downstream reach. Cladophora had a community twice as dense as P. ceratophyllum, but less diverse. The results of this study indicate that there are longitudinal differences in diatom communities in the upper Green River and host species are an important factor in determining the community composition. The importance of epiphytic diatoms in the food web, however, remains unclear.

No description available.

A fase de desenvolvimento é um importante fator a ser considerado em pesquisas sobre nutrição de bromélias. O hábito de vida dessas plantas pode mudar de: atmosférica (com folhas sem formar um tanque) para o com tanque ao longo do seu desenvolvimento. Algumas pesquisas mostraram que o conteúdo de nitrogênio foliar ou capacidade fotossintética são significantemente influenciados pela fase de desenvolvimento, porém não há registros de que a nutrição e o metabolismo do nitrogênio diferem entre bromélias jovens ou adultas. O objetivo principal deste projeto foi verificar se existem diferenças na dinâmica do metabolismo do nitrogênio (absorção, transporte e assimilação), decorrente da utilização de fontes de distintas (amônio, nitrato ou ureia), entre bromélias nas fases atmosférica ou adultas com tanque desenvolvido. Para tanto, plantas de Vriesea gigantea foram regadas com uma solução nutritiva que conteve 5mM de N total, disponível nas formas: 15NH4+ ou 15NO3- ou 15N-ureia. Foram feitas coletas temporais das raízes e de duas diferentes porções da folha (ápice e base) das bromélias jovens e de três regiões foliares (ápice, mediana e base) das folhas das bromélias adultas com tanque. Todas as amostras vegetais foram utilizadas na avaliação das atividades da: urease, redutase do nitrato, sintetase da glutamina e desidrogenase do glutamato; e da quantificação da abundância isotópica do 15N. Segundo os resultados, o nitrato foi considerado a fonte de nitrogênio absorvida em concentrações menores quando comparada com a ureia e o amônio pelas bromélias de ambas as fases de desenvolvimento. Entretanto, as bromélias atmosféricas mostraram ser capazes de capturar essa fonte inorgânica de nitrogênio mais eficientemente do que as bromélias com tanque, uma vez que o nitrato foi absorvido, transportado e assimilado rapidamente na 1ª hora após o fornecimento dessa fonte. Já para as bromélias adultas, a absorção do nitrato foi lenta e ocorreu, principalmente, no final do experimento (12ª e 24ª hora). O amônio e a ureia foram as fontes absorvidas em maiores concentrações tanto pelas bromélias jovens quanto pelas adultas. Entretanto, as bromélias atmosféricas foram capazes de captar e metabolizar maiores concentrações de nitrogênio proveniente do amônio, enquanto que as da fase adulta com tanque foram mais aptas a absorver e assimilar maiores concentrações de ureia em seus tecidos. A bromélia V. gigantea pode mudar a sua morfologia e fisiologia ao longo de seu desenvolvimento, tornando-se apta a captar as fontes de nitrogênio que, talvez, sejam mais abundantes em cada fase de seu desenvolvimento. A água da chuva que contém, principalmente, fontes inorgânicas de nitrogênio diluídas, pode ser o principal meio por onde as bromélias jovens captam o nitrogênio. Ao desenvolverem um tanque, as bromélias podem mudar a sua fisiologia, capturando preferencialmente fontes de nitrogênio provenientes de matéria orgânica decomposta que se acumula no interior da cisterna. As raízes das bromélias atmosféricas também mostraram cumprir um papel fundamental na nutrição dessas plantas durante a fase juvenil, pois aumentaram a capacidade de absorção e assimilação de fontes de nitrogênio. Quando as bromélias iniciam o desenvolvimento de um tanque, as bases das folhas passaram a assumir a função do sistema radicular, enquanto que as raízes, talvez, começassem a diminuir sua capacidade de captar os nutrientes do meio ambiente. Os resultados bioquímicos demonstraram que existe uma forte sincronização de todas as etapas do metabolismo do nitrogênio (absorção, transporte e assimilação) envolvendo diferentes partes do corpo das bromélias (raízes, porções foliares da base, mediana ou ápice) de ambas as fases de desenvolvimento, sugerindo que nos tecidos vegetais dessas plantas, existe uma fina regulação de todos os processos fisiológicos e metabólicos que compreendem o metabolismo do nitrogênio. Essa regulação controlada seria necessária para que as bromélias atmosféricas ou com tanque desenvolvido consigam absorver, transportar e assimilar as fontes de nitrogênio rapidamente e com grande eficiência. Para finalizar, o novo termo \"bromélia epífita jovem sem tanque\" foi sugerido para se referir à bromélia V. gigantea na fase juvenil ao invés de \"bromélia epífita atmosférica\". As raízes dessa bromélia jovem demonstraram ter um papel fundamental nos processos de absorção e assimilação das fontes de nitrogênio, uma característica que geralmente não é atribuída para as raízes das bromélias com o hábito de vida atmosférico / The stages of ontogenetic development of bromeliad can be an important feature to be considered in the physiology studies because the young plants can be classified as atmospheric bromeliads, while the adult plants have a special structure formed by leaves called tank. Some studies showed that some physiological characteristics can be influenced by the stages of ontogenetic development in bromeliads as photosynthetic taxes or the total nitrogen (N) content in leaves. However, there are no records that nutrition and nitrogen metabolism differ between young and adult epiphytic bromeliads. The objective of this project was to verify the existence of differences in the dynamics of nitrogen metabolism (absorption, transportation and assimilation) arising from the use of distinct nitrogen sources (NH4+, NO3- or urea) in epiphytic bromeliad Vriesea gigantea with different stages of ontogenetic development (atmospheric or tank). A nutrient solution, consisting 5mM of total N, was offered to bromeliads. Three different forms of N sources were used: NH4+, NO3- or urea, enriched with 15N isotopes. Three distinct portions of leaf (apex, middle and base) of adult tank bromeliad and two different regions of leaf (apex and base) and roots of young bromeliads were harvested in six different times. All samples were used in enzymatic assays of urease, nitrate reductase, glutamate sinthetase and glutamate dehydrogenase and in the 15N isotope quantification. According to the results, the nitrate was considered the nitrogen source absorbed at lower concentration by young and adult bromeliads. The atmospheric bromeliads were able to capture nitrate more efficiently than the tank plants, since this inorganic nitrogen source was absorbed and assimilated quickly in the 1st hour of the experimental time while the tank bromeliads absorbed nitrate slowly at the end of the experiment (12th and 24th hour). Ammonium and urea sources were absorbed in higher concentrations by atmospheric and tank bromeliads. The young bromeliads were able to absorb and assimilate higher concentrations of nitrogen from ammonium, while tank bromeliad absorbed and assimilated higher concentrations of urea. In each development stage, the epiphytic bromeliad V. gigantea can absorb and assimilate the nitrogen sources which are more available in the environment. The atmospheric bromeliads get to absorb diluted nutrients as inorganic nitrogen sources mainly from rainwater. After the tank structure developed in the rosette, the morphology and/or physiology features changes in the adult bromeliads. The tank bromeliads get to absorb mainly organic nitrogen sources from decomposed organic matter which accumulates inside the tank. The roots of atmospheric bromeliads also showed an important role in the nutrition of the young plants since the atmospheric bromeliads get to improve the nitrogen sources uptake and nitrogen assimilation. When the bromeliads developed a tank, the bases of the leaves might assume the absorption function, whereas the roots, perhaps, might decrease its capacity to capture the nutrients from the environment. The biochemical results showed that there is a strong synchronization of all stages of nitrogen metabolism (uptake, transport and assimilation) involving different body parts of bromeliads (roots, leaf portions of the base, middle or apex) of both development stages, suggesting that there might have a thin regulation of all physiological and metabolic processes of nitrogen metabolism in the bromeliad\'s tissues. This controlled regulation might be important to the atmospheric or tank bromeliads are able to absorb, allocate and assimilate nitrogen sources quickly and with great efficiency. Finally, the terminology “atmospheric epiphytic bromeliad” might not be appropriated to refer to young plants since their roots showed an important role in the absorption and assimilation of nitrogen sources. This feature is not usually attributed to the roots of atmospheric bromeliads. Then, the new terminology “young epiphytic bromeliad without tank” was suggested to refer the bromeliad V. gigantea in the juvenile phase

A fase de desenvolvimento é um importante fator a ser considerado em pesquisas sobre nutrição de bromélias. O hábito de vida dessas plantas pode mudar de: atmosférica (com folhas sem formar um tanque) para o com tanque ao longo do seu desenvolvimento. Algumas pesquisas mostraram que o conteúdo de nitrogênio foliar ou capacidade fotossintética são significantemente influenciados pela fase de desenvolvimento, porém não há registros de que a nutrição e o metabolismo do nitrogênio diferem entre bromélias jovens ou adultas. O objetivo principal deste projeto foi verificar se existem diferenças na dinâmica do metabolismo do nitrogênio (absorção, transporte e assimilação), decorrente da utilização de fontes de distintas (amônio, nitrato ou ureia), entre bromélias nas fases atmosférica ou adultas com tanque desenvolvido. Para tanto, plantas de Vriesea gigantea foram regadas com uma solução nutritiva que conteve 5mM de N total, disponível nas formas: 15NH4+ ou 15NO3- ou 15N-ureia. Foram feitas coletas temporais das raízes e de duas diferentes porções da folha (ápice e base) das bromélias jovens e de três regiões foliares (ápice, mediana e base) das folhas das bromélias adultas com tanque. Todas as amostras vegetais foram utilizadas na avaliação das atividades da: urease, redutase do nitrato, sintetase da glutamina e desidrogenase do glutamato; e da quantificação da abundância isotópica do 15N. Segundo os resultados, o nitrato foi considerado a fonte de nitrogênio absorvida em concentrações menores quando comparada com a ureia e o amônio pelas bromélias de ambas as fases de desenvolvimento. Entretanto, as bromélias atmosféricas mostraram ser capazes de capturar essa fonte inorgânica de nitrogênio mais eficientemente do que as bromélias com tanque, uma vez que o nitrato foi absorvido, transportado e assimilado rapidamente na 1ª hora após o fornecimento dessa fonte. Já para as bromélias adultas, a absorção do nitrato foi lenta e ocorreu, principalmente, no final do experimento (12ª e 24ª hora). O amônio e a ureia foram as fontes absorvidas em maiores concentrações tanto pelas bromélias jovens quanto pelas adultas. Entretanto, as bromélias atmosféricas foram capazes de captar e metabolizar maiores concentrações de nitrogênio proveniente do amônio, enquanto que as da fase adulta com tanque foram mais aptas a absorver e assimilar maiores concentrações de ureia em seus tecidos. A bromélia V. gigantea pode mudar a sua morfologia e fisiologia ao longo de seu desenvolvimento, tornando-se apta a captar as fontes de nitrogênio que, talvez, sejam mais abundantes em cada fase de seu desenvolvimento. A água da chuva que contém, principalmente, fontes inorgânicas de nitrogênio diluídas, pode ser o principal meio por onde as bromélias jovens captam o nitrogênio. Ao desenvolverem um tanque, as bromélias podem mudar a sua fisiologia, capturando preferencialmente fontes de nitrogênio provenientes de matéria orgânica decomposta que se acumula no interior da cisterna. As raízes das bromélias atmosféricas também mostraram cumprir um papel fundamental na nutrição dessas plantas durante a fase juvenil, pois aumentaram a capacidade de absorção e assimilação de fontes de nitrogênio. Quando as bromélias iniciam o desenvolvimento de um tanque, as bases das folhas passaram a assumir a função do sistema radicular, enquanto que as raízes, talvez, começassem a diminuir sua capacidade de captar os nutrientes do meio ambiente. Os resultados bioquímicos demonstraram que existe uma forte sincronização de todas as etapas do metabolismo do nitrogênio (absorção, transporte e assimilação) envolvendo diferentes partes do corpo das bromélias (raízes, porções foliares da base, mediana ou ápice) de ambas as fases de desenvolvimento, sugerindo que nos tecidos vegetais dessas plantas, existe uma fina regulação de todos os processos fisiológicos e metabólicos que compreendem o metabolismo do nitrogênio. Essa regulação controlada seria necessária para que as bromélias atmosféricas ou com tanque desenvolvido consigam absorver, transportar e assimilar as fontes de nitrogênio rapidamente e com grande eficiência. Para finalizar, o novo termo \"bromélia epífita jovem sem tanque\" foi sugerido para se referir à bromélia V. gigantea na fase juvenil ao invés de \"bromélia epífita atmosférica\". As raízes dessa bromélia jovem demonstraram ter um papel fundamental nos processos de absorção e assimilação das fontes de nitrogênio, uma característica que geralmente não é atribuída para as raízes das bromélias com o hábito de vida atmosférico / The stages of ontogenetic development of bromeliad can be an important feature to be considered in the physiology studies because the young plants can be classified as atmospheric bromeliads, while the adult plants have a special structure formed by leaves called tank. Some studies showed that some physiological characteristics can be influenced by the stages of ontogenetic development in bromeliads as photosynthetic taxes or the total nitrogen (N) content in leaves. However, there are no records that nutrition and nitrogen metabolism differ between young and adult epiphytic bromeliads. The objective of this project was to verify the existence of differences in the dynamics of nitrogen metabolism (absorption, transportation and assimilation) arising from the use of distinct nitrogen sources (NH4+, NO3- or urea) in epiphytic bromeliad Vriesea gigantea with different stages of ontogenetic development (atmospheric or tank). A nutrient solution, consisting 5mM of total N, was offered to bromeliads. Three different forms of N sources were used: NH4+, NO3- or urea, enriched with 15N isotopes. Three distinct portions of leaf (apex, middle and base) of adult tank bromeliad and two different regions of leaf (apex and base) and roots of young bromeliads were harvested in six different times. All samples were used in enzymatic assays of urease, nitrate reductase, glutamate sinthetase and glutamate dehydrogenase and in the 15N isotope quantification. According to the results, the nitrate was considered the nitrogen source absorbed at lower concentration by young and adult bromeliads. The atmospheric bromeliads were able to capture nitrate more efficiently than the tank plants, since this inorganic nitrogen source was absorbed and assimilated quickly in the 1st hour of the experimental time while the tank bromeliads absorbed nitrate slowly at the end of the experiment (12th and 24th hour). Ammonium and urea sources were absorbed in higher concentrations by atmospheric and tank bromeliads. The young bromeliads were able to absorb and assimilate higher concentrations of nitrogen from ammonium, while tank bromeliad absorbed and assimilated higher concentrations of urea. In each development stage, the epiphytic bromeliad V. gigantea can absorb and assimilate the nitrogen sources which are more available in the environment. The atmospheric bromeliads get to absorb diluted nutrients as inorganic nitrogen sources mainly from rainwater. After the tank structure developed in the rosette, the morphology and/or physiology features changes in the adult bromeliads. The tank bromeliads get to absorb mainly organic nitrogen sources from decomposed organic matter which accumulates inside the tank. The roots of atmospheric bromeliads also showed an important role in the nutrition of the young plants since the atmospheric bromeliads get to improve the nitrogen sources uptake and nitrogen assimilation. When the bromeliads developed a tank, the bases of the leaves might assume the absorption function, whereas the roots, perhaps, might decrease its capacity to capture the nutrients from the environment. The biochemical results showed that there is a strong synchronization of all stages of nitrogen metabolism (uptake, transport and assimilation) involving different body parts of bromeliads (roots, leaf portions of the base, middle or apex) of both development stages, suggesting that there might have a thin regulation of all physiological and metabolic processes of nitrogen metabolism in the bromeliad\'s tissues. This controlled regulation might be important to the atmospheric or tank bromeliads are able to absorb, allocate and assimilate nitrogen sources quickly and with great efficiency. Finally, the terminology “atmospheric epiphytic bromeliad” might not be appropriated to refer to young plants since their roots showed an important role in the absorption and assimilation of nitrogen sources. This feature is not usually attributed to the roots of atmospheric bromeliads. Then, the new terminology “young epiphytic bromeliad without tank” was suggested to refer the bromeliad V. gigantea in the juvenile phase

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第20586号 / 農博第2238号 / 新制||農||1052(附属図書館) / 学位論文||H29||N5075(農学部図書室) / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 神﨑 護, 教授 北島 薫, 教授 井鷺 裕司 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

As orquídeas são a maior família das plantas monocotiledôneas, sendo o Brasil um dos países contém grande diversidade de espécies. As orquídeas são, em sua maioria, alógamas e possuem mecanismos sofisticados para evitar a autopolinização. Os insetos são os agentes polinizadores mais comuns, mas também podem ser polinizados por aves como beija-flores. Tradicionalmente as espécies Cattleya coccinea e C. mantiqueirae tem sido reconhecidas como distintas de acordo com caracteres morfológicos, distribuição geográfica e época de floração. Esses critérios, entretanto, não permitem a identificação clara de espécies, uma vez que muitos indivíduos apresentam morfologia e fenologia intermediárias. Nesse contexto, esse estudo tem como objetivo contribuir para o conhecimento taxonômico e evolutivo de orquídeas brasileiras do gênero Cattleya. Especificamente, propõe-se rever a atual delimitação entre as espécies C. coccinea e C. mantiqueirae e caracterizar a diversidade genética entre e dentro de populações dessas espécies a partir de marcadores moleculares ISSR. Para testar se a atual delimitação de espécies corresponde a linhagens filogenética distintas, foram realizadas coletas em seis localidades da região Sudeste. Foram testados 20 iniciadores ISSR, dos quais 13 foram otimizados para obtenção de dados. Os géis de ISSR obtidos foram utilizados para construção de uma matriz binária representando a presença/ausência de fragmentos amplificados. A matriz contendo 173 indivíduos e 295 caracteres foi analisada com algoritmo de neighbor-joining e o critério de parcimônia máxima para obtenção de hipóteses filogenéticas. Os resultados indicam que as espécies tradicionalmente reconhecidas, C. coccinea e C. mantiqueirae, não constituem grupos monofiléticos e, portanto, não podem ser reconhecidas como espécies distintas de acordo com o conceito filogenético de espécies. Os resultados também apontam que as populações amostradas constituem grupos monofiléticos com altos valores de confiança e que o complexo C. coccinea-C. mantiqueirae não constitui um grupo monofilético. O parafiletismo do grupo é determinado pela posição da população de Lima Duarte/MG, que constitui um clado irmão da espécie C. brevipedunculata (ocorrente na Serra do Espinhaço) e C. wittigiana (restrita ao Estado do Espírito Santo). Os resultados de análises de genética de populações corroboram com os resultados da análise filogenética e indicam que as populações possuem baixos índices de diversidade genética entre indivíduos e que a maior diversidade encontra-se entre populações. Por serem plantas com alto valor ornamental e sofrerem com ações antrópicas constantes, esse estudo foi de fundamental importância para permitir estratégias viáveis para a manutenção e conservação da diversidade genética dessas populações de orquídeas. / Orchids represent the largest family of monocots, with great diversity of species in Brazil. These plants are generally allogamous and bear sofisticated mechanisms to avoid self-pollination. Insects are by far the most common pollinators, but birds (i.e hummingbirds) may also be important. Within Cattleya, the species C. coccinea and C. mantiqueirae have been distinguished by morphological characters, geographical distribution and flowering period. Such criteria, however, do not allow a clear identification of species, since many specimens show intermediate morphological and phenological variation. The goal of this study is to contribute to the understanding of taxonomical and evolutionary aspects of Brazilian orchids, especially within the genus Cattleya. In order to achieve that I revised current species limits within the C. coccinea-C. mantiqueirae species complex. The study was based on phylogenetic and genetic diversity analyses among and within populations considering ISSR molecular markers. Six populations from Southeastern Brazil were considered. I tested 20 ISSR primers, of which 13 were used in this study. Presence/absence of fragments visualized in agarose gels were used to built a binary matrix. The analyses considered 173 individuals and 295 caracters (fragments). Phylogenetic analyses were performed according to distance (neigbor-joining) and parsimony criteria. According to the results, the species C. coccinea and C. mantiqueirae do not constitute monophyletic groups and, therefore, cannot be recognized as distinct according to the phylogenetic species criterion. Also the C. coccinea-C. mantiqueirae species complex is paraphyletic considering the closely related species C. brevipedunculata (from Serra do Espinhaço) and C. wittigiana (from Espírito Santo State). The population of Lima Duarte/MG is phylogenetically more closely related to such species than to other populations of C. coccinea and C. mantiqueirae. On the other hand, the studied populations comprise strong monophyletic groups. Population genetics analyses agree with phylogenetic results. All populations show low diversity indices among individuals. Also, the greatest portion of genetic diversity was found between populations. Orchids belonging to the C. coccinea-C. mantiqueirae species complex are high ornamental species, with great anthropogenic pressure. For this reason this study was important to allow conservation strategies to maintain and monitor genetic and morphological diversity of populations.

As orquídeas são a maior família das plantas monocotiledôneas, sendo o Brasil um dos países contém grande diversidade de espécies. As orquídeas são, em sua maioria, alógamas e possuem mecanismos sofisticados para evitar a autopolinização. Os insetos são os agentes polinizadores mais comuns, mas também podem ser polinizados por aves como beija-flores. Tradicionalmente as espécies Cattleya coccinea e C. mantiqueirae tem sido reconhecidas como distintas de acordo com caracteres morfológicos, distribuição geográfica e época de floração. Esses critérios, entretanto, não permitem a identificação clara de espécies, uma vez que muitos indivíduos apresentam morfologia e fenologia intermediárias. Nesse contexto, esse estudo tem como objetivo contribuir para o conhecimento taxonômico e evolutivo de orquídeas brasileiras do gênero Cattleya. Especificamente, propõe-se rever a atual delimitação entre as espécies C. coccinea e C. mantiqueirae e caracterizar a diversidade genética entre e dentro de populações dessas espécies a partir de marcadores moleculares ISSR. Para testar se a atual delimitação de espécies corresponde a linhagens filogenética distintas, foram realizadas coletas em seis localidades da região Sudeste. Foram testados 20 iniciadores ISSR, dos quais 13 foram otimizados para obtenção de dados. Os géis de ISSR obtidos foram utilizados para construção de uma matriz binária representando a presença/ausência de fragmentos amplificados. A matriz contendo 173 indivíduos e 295 caracteres foi analisada com algoritmo de neighbor-joining e o critério de parcimônia máxima para obtenção de hipóteses filogenéticas. Os resultados indicam que as espécies tradicionalmente reconhecidas, C. coccinea e C. mantiqueirae, não constituem grupos monofiléticos e, portanto, não podem ser reconhecidas como espécies distintas de acordo com o conceito filogenético de espécies. Os resultados também apontam que as populações amostradas constituem grupos monofiléticos com altos valores de confiança e que o complexo C. coccinea-C. mantiqueirae não constitui um grupo monofilético. O parafiletismo do grupo é determinado pela posição da população de Lima Duarte/MG, que constitui um clado irmão da espécie C. brevipedunculata (ocorrente na Serra do Espinhaço) e C. wittigiana (restrita ao Estado do Espírito Santo). Os resultados de análises de genética de populações corroboram com os resultados da análise filogenética e indicam que as populações possuem baixos índices de diversidade genética entre indivíduos e que a maior diversidade encontra-se entre populações. Por serem plantas com alto valor ornamental e sofrerem com ações antrópicas constantes, esse estudo foi de fundamental importância para permitir estratégias viáveis para a manutenção e conservação da diversidade genética dessas populações de orquídeas. / Orchids represent the largest family of monocots, with great diversity of species in Brazil. These plants are generally allogamous and bear sofisticated mechanisms to avoid self-pollination. Insects are by far the most common pollinators, but birds (i.e hummingbirds) may also be important. Within Cattleya, the species C. coccinea and C. mantiqueirae have been distinguished by morphological characters, geographical distribution and flowering period. Such criteria, however, do not allow a clear identification of species, since many specimens show intermediate morphological and phenological variation. The goal of this study is to contribute to the understanding of taxonomical and evolutionary aspects of Brazilian orchids, especially within the genus Cattleya. In order to achieve that I revised current species limits within the C. coccinea-C. mantiqueirae species complex. The study was based on phylogenetic and genetic diversity analyses among and within populations considering ISSR molecular markers. Six populations from Southeastern Brazil were considered. I tested 20 ISSR primers, of which 13 were used in this study. Presence/absence of fragments visualized in agarose gels were used to built a binary matrix. The analyses considered 173 individuals and 295 caracters (fragments). Phylogenetic analyses were performed according to distance (neigbor-joining) and parsimony criteria. According to the results, the species C. coccinea and C. mantiqueirae do not constitute monophyletic groups and, therefore, cannot be recognized as distinct according to the phylogenetic species criterion. Also the C. coccinea-C. mantiqueirae species complex is paraphyletic considering the closely related species C. brevipedunculata (from Serra do Espinhaço) and C. wittigiana (from Espírito Santo State). The population of Lima Duarte/MG is phylogenetically more closely related to such species than to other populations of C. coccinea and C. mantiqueirae. On the other hand, the studied populations comprise strong monophyletic groups. Population genetics analyses agree with phylogenetic results. All populations show low diversity indices among individuals. Also, the greatest portion of genetic diversity was found between populations. Orchids belonging to the C. coccinea-C. mantiqueirae species complex are high ornamental species, with great anthropogenic pressure. For this reason this study was important to allow conservation strategies to maintain and monitor genetic and morphological diversity of populations.

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