Universiẗat, Diss., 2004--Bonn.

Universiẗat, Diss., 2003--Münster (Westfalen).

The Stress-gradient hypothesis predicates a change of interspecies relations from negative to positive according to the stress gradient. The basic assumption is that the presence of one species (the facilitator) makes the growth of other species easier. In this study was determined based on the 5years experiment, whether the interspecies interactions (i.e. the importance of facilitation and competition) changes according to the hydrological conditions. Three wetland species (Calamagrostis canescens, Carex elongata and Deschampsia cespitosa) were planted in experimental pots with the presence and absence of the dominant species (Carex elata). The hydrological gradient (= the stress gradient) was simulated by three types of hydrological conditions: dry, fluctuating and wet. The success of the species within the specific conditions was correlated with the fitness-related characteristics of the plants including the biomass, the number of ramets and the height of the plants. Following hypotheses were tested: i) at a low intensity of stress (with the wet treatment), the C. elata represents a competitor for other species. On the other hand, at a high intensity of stress (with the dry treatment), the C. elata represents a facilitator, making it easier to the other coexisting species to grow. This presumption was confirmed only with the D. cespitosa, which was more successful under dry treatment with the presence of a dominant species, which facilitated it. With the other two species the change of interspecific relations was not observed and the relationships remained negative. Furthermore the results showed, that in the dry treatment with the presence of a dominant species, there was a lower intensity of competition among the coexisting species. The experiment showed, that the interactions of particular species with dominant species can vary according to the stress gradient. The hydrological gradient also influences the character and intensity of interactions among the species.

The aim of the presented work was to evaluate measured data in a Paulovnia plantation clone in vitro 112 grown in Strelice u Brna during the years of 2016 and 2017. This clone is a hybrid of Paulownia elongata × Paulownia fortunei. In 2016, 686 carefully marked plants were planted at the plot. The whole area of plantation was separated into the four sectors according to micro-relief of the terrain and use of a different drill diameter during the planting, what results has been reflected. Furthermore, three different approaches of protection against frost damage, specifically bandage of stem by non-woven fabric, cower of stem base part (root neck) by peat or soil, were applied. From the obtained results, during the first two years after planting, come out that root system of clone in vitro 112 is resistant to frost damage despite to applied cower of soil or peat, and that above part of plant can be protected by bandage, but it is necessary to investigate the best time for bandage removing as during this procedure flushing shoots were mostly broken. Bandage did not protect the tested plants against frost damage as well as all the rest tested protection approaches. On the average, the frost damaged about 72 % of plant height downward from the top. Total mortality of plants planted in 2016 was 4 % in the autumn of 2017, therefore we can deduce that mortality will be not limiting factor for Paulovnia growing in CR. Next considering parameter was an occurrence of stem forking (two or three sprouts per stem), which occurred only on 2 % of plants. When keeping the basic silvicultural technology during plantation and consequent tending of plantation, Paulownia clone in vitro 112 can grow under conditions of the Czech Republic.

Diorhabda elongata elongata leaf beetles were released at two field locations in the upper Colorado River watershed of Texas in 2003 and 2004 for the biological control of invasive Tamarix, exotic trees deteriorating riparian ecosystems of western North America. Establishment and biological success were monitored using trees on transects from the release points. D. elongata elongata released at the Lake Thomas site in August 2003 successfully overwintered and were recovered in the spring 2004; however, beetles were not present after June 2004. The April 2004 release at Beals Creek led to establishment and survival during 2005 and 2006. Mean abundance increased from less than five insects per tree per 2 minute count in August 2004 to more than 40 insects per tree per 2 minute count in August 2006. By then the population was dispersed throughout an area of approximately 12 hectares and beetles were present on 100% of the 47 trees surveyed, 57% of which were at least 90% defoliated. To measure the impact of beetle defoliation on Tamarix, nonstructural carbohydrates (NCHOs) were measured in manipulative field cage experiments in Texas and natural experiments in Nevada. There was no significant difference in NCHOs between trees with versus trees without beetle herbivory in the cage experiment, although spring foliage regrowth was reduced by 35% in trees defoliated the previous fall. In Nevada, root crown tissue was sampled in 2005 and 2006 from trees that had experienced 0-4 years of defoliation. In 2005, NCHO concentrations differed between tree stands and ranged from 9.0 ± 0.8% (Mean ± SE) in non-defoliated trees to 3.2 ± 0.4%, 2.1 ± 0.4% and 2.3 ± 0.4% in trees defoliated for 1, 2 and 3 successive years, respectively. NCHO concentrations in 2006 were similar, ranging from 13.6 ± 0.9% in non-defoliated trees to 7.6 ± 0.8%, 2.3 ± 0.4%, 1.5 ± 0.3% and 1.7 ± 0.4% in trees defoliated for 1, 2, 3 and 4 years, respectively. The establishment, biological success and host impact of D. elongata leaf beetles suggest there is potential for biological control of Tamarix in the United States.

Diorhabda elongata elongata leaf beetles were released at two field locations in the upper Colorado River watershed of Texas in 2003 and 2004 for the biological control of invasive Tamarix, exotic trees deteriorating riparian ecosystems of western North America. Establishment and biological success were monitored using trees on transects from the release points. D. elongata elongata released at the Lake Thomas site in August 2003 successfully overwintered and were recovered in the spring 2004; however, beetles were not present after June 2004. The April 2004 release at Beals Creek led to establishment and survival during 2005 and 2006. Mean abundance increased from less than five insects per tree per 2 minute count in August 2004 to more than 40 insects per tree per 2 minute count in August 2006. By then the population was dispersed throughout an area of approximately 12 hectares and beetles were present on 100% of the 47 trees surveyed, 57% of which were at least 90% defoliated. To measure the impact of beetle defoliation on Tamarix, nonstructural carbohydrates (NCHOs) were measured in manipulative field cage experiments in Texas and natural experiments in Nevada. There was no significant difference in NCHOs between trees with versus trees without beetle herbivory in the cage experiment, although spring foliage regrowth was reduced by 35% in trees defoliated the previous fall. In Nevada, root crown tissue was sampled in 2005 and 2006 from trees that had experienced 0-4 years of defoliation. In 2005, NCHO concentrations differed between tree stands and ranged from 9.0 ± 0.8% (Mean ± SE) in non-defoliated trees to 3.2 ± 0.4%, 2.1 ± 0.4% and 2.3 ± 0.4% in trees defoliated for 1, 2 and 3 successive years, respectively. NCHO concentrations in 2006 were similar, ranging from 13.6 ± 0.9% in non-defoliated trees to 7.6 ± 0.8%, 2.3 ± 0.4%, 1.5 ± 0.3% and 1.7 ± 0.4% in trees defoliated for 1, 2, 3 and 4 years, respectively. The establishment, biological success and host impact of D. elongata leaf beetles suggest there is potential for biological control of Tamarix in the United States.

Gelasine Herb. (Tigridieae: Iridaceae) é composto por sete espécies nativas da América do Sul, sendo três delas encontradas no Rio Grande do Sul (Brasil): G. coerulea (Vell.) Ravenna, G. elongata (Graham) Ravenna e G. uruguaiensis Ravenna. São plantas bulbosas de folhas plicadas, flores perfeitas azuis ou roxas e compostas por dois conjuntos de tépalas desiguais. Gelasine elongata e G. coerulea encontram-se na lista de espécies ameaçadas para o RS, sendo a primeira delas ameaçada e a segunda criticamente ameaçada. Apesar de seu atual estado de vulnerabilidade, Gelasine é um gênero ainda pouco estudado, não havendo nenhuma informação quanto à variabilidade e diversidade genética. Os dados citogenéticos são também ainda escassos. Assim, a presente dissertação tem por objetivo caracterizar as três espécies de Gelasine ocorrentes no sul do Brasil quanto a aspectos moleculares, citogenéticos, além de compreender suas relações. Para a caracterização da diversidade genética foram usadas duas populações de G. coerulea e duas de G. elongata; não foi possível a utilização de G. uruguaiensis em função do número restrito de indivíduos. As amostras de DNA foram obtidas a partir de folhas das espécies mencionadas e empregada a técnica de ISSR (Inter Simple Sequence Repeat). Foram testados 44 primers para ISSR, destes, 12 apresentaram um bom padrão de amplificação que em conjunto geraram 91 loci. A quantidade de bandas por primer variou em média de 7,5. Este trabalho resultou em dados inéditos para o gênero Gelasine quanto à variabilidade genética inter e intra-populacional. Os resultados indicam que a variação genética intrapopulacional é muito baixa e que a maior diversidade encontrada para estas espécies ocorreu entre as populações. Não foi verificada correlação significativa com a distância geográfica entre as populações. Tais resultados indicam que o sistema reprodutivo, o método de dispersão de sementes e a presença de descendência clonal oriunda da divisão dos bulbos subterrâneos são fatores de grande influência na diversidade. Para caracterização citogenética das espécies foi empregada coloração convencional e bandeamento CMA/DAPI, e realizadas medidas cromossômicas. Foi também estimado o tamanho do genoma por citometria de fluxo a partir de folhas frescas das três espécies. As análises citogenéticas se mostraram bastante eficientes para a diferenciação das três espécies de Gelasine investigadas. Gelasine coerulea e G. uruguaiensis apresentam o mesmo número cromossômico básico e somático (2n = 2x = 14), não sendo encontrados citótipos poliploides. Ambas têm cariótipos relativamente simétricos, porém se mostram bastante distintas quanto ao tamanho dos cromossomos e seu padrão de bandeamento, com uma grande variação na ocorrência e distribuição de sequências de DNA repetitivo (bandas CMA/DAPI). O conteúdo de DNA também permite a clara diferenciação dessas espécies, tendo G. coerulea 2C = 11,30 pg e G. uruguaiensis 2C = 16,88 pg. Gelasine elongata possui número cromossômico básico diferente das anteriores (2n = 2x = 12) e cariótipo claramente bimodal. Os cromossomos têm menor tamanho, o que, consequentemente reflete no menor tamanho de genoma (2C = 3,45 pg). Além disso, o padrão de bandas CMA/DAPI é notadamente mais simples que das outras duas espécies, onde o maior par de cromossomos (par I) exibe as únicas bandas CMA+ presentes na região da constrição secundária. Os dados obtidos para G. elongata apontam para uma maior semelhança dessa espécie com outras duas do gênero Eleuthenine (2n = 2x = 12), o que reforça os dados filogenéticos existentes, onde G. elongata está separada de G. coerulea e agrupada no mesmo ramo de Eleutherine. Não foi observado heteromorfismo cromossômico para Gelasine elongata e nem para as outras duas espécies investigadas, embora tal situação tenha sido reportada para aquela espécie. Os dados obtidos para Gelasine com o uso dos fluorocromos CMA e DAPI, bem como os demais parâmetros citogenéticos investigados permitiram a clara diferenciação entre as espécies. Associados a uma abordagem filogenética, tais resultados auxiliam a compreensão das relações entre essas espécies e sua evolução. / Gelasine Herb. (Tigridieae: Iridaceae) comprises seven native species from South America, three of them are found in Rio Grande do Sul (Brasil): G. coerulea (Vell.) Ravenna, G. elongata (Graham) Ravenna and G. uruguaiensis Ravenna. These species are bulbous plants with plicate leaves and blue or violet perfect flowers which are composed of two unequal groups of tepals. Gelasine elongata and G. coerulea are included in the list of endangered species from RS, the first one is considered endangered and the latter, critically endangered. Notwithstanding its current vulnerability status, Gelasine is still a poorly studied genus and genetic variability and diversity information concerning its species are lacking. Cytogenetic data are also scarce. Thus the present dissertation aims to characterize the three Gelasine species occurring in Southern Brazil regarding its molecular and cytogenetic aspects in addition to understand their relationships. To characterize their genetic diversity, two populations of G. coerulea and two of G. elongata were used; it was not possible to investigate G. uruguaiensis due to its restricted number of individuals. DNA samples were obtained from leaves of the aforementioned species and ISSR (Inter Simple Sequence Repeat) technique was employed. Fourty-four ISSR primers were tested, 12 of these presented good amplification pattern which generated a total of 97 loci. The number of bands per primer had an average of 7.5. The present study resulted in novelty data for Gelasine concerning its inter and intrapopulation genetic variability. The results indicate a very low intrapopulation genetic variation and most of the diversity found in these species occurred among their populations. No significant correlation was verified between geographical distances of populations. Such results indicate that reproductive system, seed dispersal mechanisms and presence of clonal descendants generated from divisions of subterranean bulbs are factors that greatly influence in diversity. For cytogenetic characterization of the species, conventional staining and CMA/DAPI banding were employed and chromosome measurements were made. Also, genome size was estimated through flow cytometry using fresh leaves from the three species. Cytogenetic analyses were very efficient to differentiate all investigated species of Gelasine. Gelasine coerulea and G. uruguaiensis have the same basic and somatic chromosome number (2n = 2x = 14); polyploid cytotypes were not found. Both species display fairly symmetric karyotypes, however they are very distinct with respect to chromosome sizes and banding patterns, with a great variation in the occurrence and distribution of repetitive DNA sequences (CMA/DAPI bands). DNA content also allows clear differentiation of these species; G. coerulea has 2C = 11,30 pg and G. uruguaiensis has 2C = 16,88 pg. Gelasine elongata has a different base chromosome number than both former species (2n = 2x = 12) and a clearly bimodal karyotype. Its chromosomes are smaller which, consequently, reflects on the smaller genome size (2C = 3,45 pg). Furthermore, its CMA/DAPI band pattern is markedly simpler than the ones from the other two species, where the largest chromosome pair (pair I) contains the only CMA+ bands present in the secondary constriction region. Data obtained from G. elongata points out a larger resemblance between this species and two others belonging to Eleuthenine (2n = 2x = 12), which supports the phylogenetic data where G. elongata is separate from G. coerulea and groups with Eleutherine. Chromosome heteromorphism was not observed in Gelasine elongata nor in the two other investigated species, even though it had been reported for the first one. Data obtained from Gelasine with the use of CMA and DAPI fluorochromes, along with the other cytogenetic parameters investigated, allowed clear differentiation between species. Allied to a phylogenetic approach, these results can bring better understanding to the relations between these species and their evolution.

Gelasine Herb. (Tigridieae: Iridaceae) é composto por sete espécies nativas da América do Sul, sendo três delas encontradas no Rio Grande do Sul (Brasil): G. coerulea (Vell.) Ravenna, G. elongata (Graham) Ravenna e G. uruguaiensis Ravenna. São plantas bulbosas de folhas plicadas, flores perfeitas azuis ou roxas e compostas por dois conjuntos de tépalas desiguais. Gelasine elongata e G. coerulea encontram-se na lista de espécies ameaçadas para o RS, sendo a primeira delas ameaçada e a segunda criticamente ameaçada. Apesar de seu atual estado de vulnerabilidade, Gelasine é um gênero ainda pouco estudado, não havendo nenhuma informação quanto à variabilidade e diversidade genética. Os dados citogenéticos são também ainda escassos. Assim, a presente dissertação tem por objetivo caracterizar as três espécies de Gelasine ocorrentes no sul do Brasil quanto a aspectos moleculares, citogenéticos, além de compreender suas relações. Para a caracterização da diversidade genética foram usadas duas populações de G. coerulea e duas de G. elongata; não foi possível a utilização de G. uruguaiensis em função do número restrito de indivíduos. As amostras de DNA foram obtidas a partir de folhas das espécies mencionadas e empregada a técnica de ISSR (Inter Simple Sequence Repeat). Foram testados 44 primers para ISSR, destes, 12 apresentaram um bom padrão de amplificação que em conjunto geraram 91 loci. A quantidade de bandas por primer variou em média de 7,5. Este trabalho resultou em dados inéditos para o gênero Gelasine quanto à variabilidade genética inter e intra-populacional. Os resultados indicam que a variação genética intrapopulacional é muito baixa e que a maior diversidade encontrada para estas espécies ocorreu entre as populações. Não foi verificada correlação significativa com a distância geográfica entre as populações. Tais resultados indicam que o sistema reprodutivo, o método de dispersão de sementes e a presença de descendência clonal oriunda da divisão dos bulbos subterrâneos são fatores de grande influência na diversidade. Para caracterização citogenética das espécies foi empregada coloração convencional e bandeamento CMA/DAPI, e realizadas medidas cromossômicas. Foi também estimado o tamanho do genoma por citometria de fluxo a partir de folhas frescas das três espécies. As análises citogenéticas se mostraram bastante eficientes para a diferenciação das três espécies de Gelasine investigadas. Gelasine coerulea e G. uruguaiensis apresentam o mesmo número cromossômico básico e somático (2n = 2x = 14), não sendo encontrados citótipos poliploides. Ambas têm cariótipos relativamente simétricos, porém se mostram bastante distintas quanto ao tamanho dos cromossomos e seu padrão de bandeamento, com uma grande variação na ocorrência e distribuição de sequências de DNA repetitivo (bandas CMA/DAPI). O conteúdo de DNA também permite a clara diferenciação dessas espécies, tendo G. coerulea 2C = 11,30 pg e G. uruguaiensis 2C = 16,88 pg. Gelasine elongata possui número cromossômico básico diferente das anteriores (2n = 2x = 12) e cariótipo claramente bimodal. Os cromossomos têm menor tamanho, o que, consequentemente reflete no menor tamanho de genoma (2C = 3,45 pg). Além disso, o padrão de bandas CMA/DAPI é notadamente mais simples que das outras duas espécies, onde o maior par de cromossomos (par I) exibe as únicas bandas CMA+ presentes na região da constrição secundária. Os dados obtidos para G. elongata apontam para uma maior semelhança dessa espécie com outras duas do gênero Eleuthenine (2n = 2x = 12), o que reforça os dados filogenéticos existentes, onde G. elongata está separada de G. coerulea e agrupada no mesmo ramo de Eleutherine. Não foi observado heteromorfismo cromossômico para Gelasine elongata e nem para as outras duas espécies investigadas, embora tal situação tenha sido reportada para aquela espécie. Os dados obtidos para Gelasine com o uso dos fluorocromos CMA e DAPI, bem como os demais parâmetros citogenéticos investigados permitiram a clara diferenciação entre as espécies. Associados a uma abordagem filogenética, tais resultados auxiliam a compreensão das relações entre essas espécies e sua evolução. / Gelasine Herb. (Tigridieae: Iridaceae) comprises seven native species from South America, three of them are found in Rio Grande do Sul (Brasil): G. coerulea (Vell.) Ravenna, G. elongata (Graham) Ravenna and G. uruguaiensis Ravenna. These species are bulbous plants with plicate leaves and blue or violet perfect flowers which are composed of two unequal groups of tepals. Gelasine elongata and G. coerulea are included in the list of endangered species from RS, the first one is considered endangered and the latter, critically endangered. Notwithstanding its current vulnerability status, Gelasine is still a poorly studied genus and genetic variability and diversity information concerning its species are lacking. Cytogenetic data are also scarce. Thus the present dissertation aims to characterize the three Gelasine species occurring in Southern Brazil regarding its molecular and cytogenetic aspects in addition to understand their relationships. To characterize their genetic diversity, two populations of G. coerulea and two of G. elongata were used; it was not possible to investigate G. uruguaiensis due to its restricted number of individuals. DNA samples were obtained from leaves of the aforementioned species and ISSR (Inter Simple Sequence Repeat) technique was employed. Fourty-four ISSR primers were tested, 12 of these presented good amplification pattern which generated a total of 97 loci. The number of bands per primer had an average of 7.5. The present study resulted in novelty data for Gelasine concerning its inter and intrapopulation genetic variability. The results indicate a very low intrapopulation genetic variation and most of the diversity found in these species occurred among their populations. No significant correlation was verified between geographical distances of populations. Such results indicate that reproductive system, seed dispersal mechanisms and presence of clonal descendants generated from divisions of subterranean bulbs are factors that greatly influence in diversity. For cytogenetic characterization of the species, conventional staining and CMA/DAPI banding were employed and chromosome measurements were made. Also, genome size was estimated through flow cytometry using fresh leaves from the three species. Cytogenetic analyses were very efficient to differentiate all investigated species of Gelasine. Gelasine coerulea and G. uruguaiensis have the same basic and somatic chromosome number (2n = 2x = 14); polyploid cytotypes were not found. Both species display fairly symmetric karyotypes, however they are very distinct with respect to chromosome sizes and banding patterns, with a great variation in the occurrence and distribution of repetitive DNA sequences (CMA/DAPI bands). DNA content also allows clear differentiation of these species; G. coerulea has 2C = 11,30 pg and G. uruguaiensis has 2C = 16,88 pg. Gelasine elongata has a different base chromosome number than both former species (2n = 2x = 12) and a clearly bimodal karyotype. Its chromosomes are smaller which, consequently, reflects on the smaller genome size (2C = 3,45 pg). Furthermore, its CMA/DAPI band pattern is markedly simpler than the ones from the other two species, where the largest chromosome pair (pair I) contains the only CMA+ bands present in the secondary constriction region. Data obtained from G. elongata points out a larger resemblance between this species and two others belonging to Eleuthenine (2n = 2x = 12), which supports the phylogenetic data where G. elongata is separate from G. coerulea and groups with Eleutherine. Chromosome heteromorphism was not observed in Gelasine elongata nor in the two other investigated species, even though it had been reported for the first one. Data obtained from Gelasine with the use of CMA and DAPI fluorochromes, along with the other cytogenetic parameters investigated, allowed clear differentiation between species. Allied to a phylogenetic approach, these results can bring better understanding to the relations between these species and their evolution.

Gelasine Herb. (Tigridieae: Iridaceae) é composto por sete espécies nativas da América do Sul, sendo três delas encontradas no Rio Grande do Sul (Brasil): G. coerulea (Vell.) Ravenna, G. elongata (Graham) Ravenna e G. uruguaiensis Ravenna. São plantas bulbosas de folhas plicadas, flores perfeitas azuis ou roxas e compostas por dois conjuntos de tépalas desiguais. Gelasine elongata e G. coerulea encontram-se na lista de espécies ameaçadas para o RS, sendo a primeira delas ameaçada e a segunda criticamente ameaçada. Apesar de seu atual estado de vulnerabilidade, Gelasine é um gênero ainda pouco estudado, não havendo nenhuma informação quanto à variabilidade e diversidade genética. Os dados citogenéticos são também ainda escassos. Assim, a presente dissertação tem por objetivo caracterizar as três espécies de Gelasine ocorrentes no sul do Brasil quanto a aspectos moleculares, citogenéticos, além de compreender suas relações. Para a caracterização da diversidade genética foram usadas duas populações de G. coerulea e duas de G. elongata; não foi possível a utilização de G. uruguaiensis em função do número restrito de indivíduos. As amostras de DNA foram obtidas a partir de folhas das espécies mencionadas e empregada a técnica de ISSR (Inter Simple Sequence Repeat). Foram testados 44 primers para ISSR, destes, 12 apresentaram um bom padrão de amplificação que em conjunto geraram 91 loci. A quantidade de bandas por primer variou em média de 7,5. Este trabalho resultou em dados inéditos para o gênero Gelasine quanto à variabilidade genética inter e intra-populacional. Os resultados indicam que a variação genética intrapopulacional é muito baixa e que a maior diversidade encontrada para estas espécies ocorreu entre as populações. Não foi verificada correlação significativa com a distância geográfica entre as populações. Tais resultados indicam que o sistema reprodutivo, o método de dispersão de sementes e a presença de descendência clonal oriunda da divisão dos bulbos subterrâneos são fatores de grande influência na diversidade. Para caracterização citogenética das espécies foi empregada coloração convencional e bandeamento CMA/DAPI, e realizadas medidas cromossômicas. Foi também estimado o tamanho do genoma por citometria de fluxo a partir de folhas frescas das três espécies. As análises citogenéticas se mostraram bastante eficientes para a diferenciação das três espécies de Gelasine investigadas. Gelasine coerulea e G. uruguaiensis apresentam o mesmo número cromossômico básico e somático (2n = 2x = 14), não sendo encontrados citótipos poliploides. Ambas têm cariótipos relativamente simétricos, porém se mostram bastante distintas quanto ao tamanho dos cromossomos e seu padrão de bandeamento, com uma grande variação na ocorrência e distribuição de sequências de DNA repetitivo (bandas CMA/DAPI). O conteúdo de DNA também permite a clara diferenciação dessas espécies, tendo G. coerulea 2C = 11,30 pg e G. uruguaiensis 2C = 16,88 pg. Gelasine elongata possui número cromossômico básico diferente das anteriores (2n = 2x = 12) e cariótipo claramente bimodal. Os cromossomos têm menor tamanho, o que, consequentemente reflete no menor tamanho de genoma (2C = 3,45 pg). Além disso, o padrão de bandas CMA/DAPI é notadamente mais simples que das outras duas espécies, onde o maior par de cromossomos (par I) exibe as únicas bandas CMA+ presentes na região da constrição secundária. Os dados obtidos para G. elongata apontam para uma maior semelhança dessa espécie com outras duas do gênero Eleuthenine (2n = 2x = 12), o que reforça os dados filogenéticos existentes, onde G. elongata está separada de G. coerulea e agrupada no mesmo ramo de Eleutherine. Não foi observado heteromorfismo cromossômico para Gelasine elongata e nem para as outras duas espécies investigadas, embora tal situação tenha sido reportada para aquela espécie. Os dados obtidos para Gelasine com o uso dos fluorocromos CMA e DAPI, bem como os demais parâmetros citogenéticos investigados permitiram a clara diferenciação entre as espécies. Associados a uma abordagem filogenética, tais resultados auxiliam a compreensão das relações entre essas espécies e sua evolução. / Gelasine Herb. (Tigridieae: Iridaceae) comprises seven native species from South America, three of them are found in Rio Grande do Sul (Brasil): G. coerulea (Vell.) Ravenna, G. elongata (Graham) Ravenna and G. uruguaiensis Ravenna. These species are bulbous plants with plicate leaves and blue or violet perfect flowers which are composed of two unequal groups of tepals. Gelasine elongata and G. coerulea are included in the list of endangered species from RS, the first one is considered endangered and the latter, critically endangered. Notwithstanding its current vulnerability status, Gelasine is still a poorly studied genus and genetic variability and diversity information concerning its species are lacking. Cytogenetic data are also scarce. Thus the present dissertation aims to characterize the three Gelasine species occurring in Southern Brazil regarding its molecular and cytogenetic aspects in addition to understand their relationships. To characterize their genetic diversity, two populations of G. coerulea and two of G. elongata were used; it was not possible to investigate G. uruguaiensis due to its restricted number of individuals. DNA samples were obtained from leaves of the aforementioned species and ISSR (Inter Simple Sequence Repeat) technique was employed. Fourty-four ISSR primers were tested, 12 of these presented good amplification pattern which generated a total of 97 loci. The number of bands per primer had an average of 7.5. The present study resulted in novelty data for Gelasine concerning its inter and intrapopulation genetic variability. The results indicate a very low intrapopulation genetic variation and most of the diversity found in these species occurred among their populations. No significant correlation was verified between geographical distances of populations. Such results indicate that reproductive system, seed dispersal mechanisms and presence of clonal descendants generated from divisions of subterranean bulbs are factors that greatly influence in diversity. For cytogenetic characterization of the species, conventional staining and CMA/DAPI banding were employed and chromosome measurements were made. Also, genome size was estimated through flow cytometry using fresh leaves from the three species. Cytogenetic analyses were very efficient to differentiate all investigated species of Gelasine. Gelasine coerulea and G. uruguaiensis have the same basic and somatic chromosome number (2n = 2x = 14); polyploid cytotypes were not found. Both species display fairly symmetric karyotypes, however they are very distinct with respect to chromosome sizes and banding patterns, with a great variation in the occurrence and distribution of repetitive DNA sequences (CMA/DAPI bands). DNA content also allows clear differentiation of these species; G. coerulea has 2C = 11,30 pg and G. uruguaiensis has 2C = 16,88 pg. Gelasine elongata has a different base chromosome number than both former species (2n = 2x = 12) and a clearly bimodal karyotype. Its chromosomes are smaller which, consequently, reflects on the smaller genome size (2C = 3,45 pg). Furthermore, its CMA/DAPI band pattern is markedly simpler than the ones from the other two species, where the largest chromosome pair (pair I) contains the only CMA+ bands present in the secondary constriction region. Data obtained from G. elongata points out a larger resemblance between this species and two others belonging to Eleuthenine (2n = 2x = 12), which supports the phylogenetic data where G. elongata is separate from G. coerulea and groups with Eleutherine. Chromosome heteromorphism was not observed in Gelasine elongata nor in the two other investigated species, even though it had been reported for the first one. Data obtained from Gelasine with the use of CMA and DAPI fluorochromes, along with the other cytogenetic parameters investigated, allowed clear differentiation between species. Allied to a phylogenetic approach, these results can bring better understanding to the relations between these species and their evolution.

Orientador: Angela Regina Araujo / Resumo: Os fungos endofíticos, representam uma fonte promissora na descoberta de produtos naturais. Estes endófitos têm se revelado pela alta capacidade na produção de diversas classes de metabólitos secundários com uma ampla variedade de atividades biológicas, tais como: antimicrobiana, citotóxica, antioxidante, ansiolítica e inseticida. Estas observações motivaram o desenvolvimento do presente estudo, o qual visou a prospecção química e biológica dos fungos endofíticos associados à Platonia insignis Mart. O isolamento dos fungos endofíticos resultou em dezoito linhagens puras, sendo estes cultivados em meio líquido de MDB, para obtenção dos respectivos extratos brutos. Estes foram avaliados quanto ao perfil químico e biológico, os quais demonstram ser promissores para produção de substâncias bioativas. A prospecção inicial conduziu a seleção de dois fungos endofíticos, identificados como Diaporthe hongkongensis e Phyllosticta elongata para desenvolvimento do trabalho. Duas abordagens foram aplicadas a fim de verificar a influência da composição nutricional frente a produção metabólica de D. hongkongensis e P. elongata: cultivo em meio de MDB e cultivo em meio sólido de milho. O estudo de D. hongkongensis, cultivado em MDB, resultou no isolamento de uma dicetopiperazina, ariletilamida, acetiltriptamina e o acetato de metila-[2-oxo-2-(feniletilamino)], sendo o primeiro relato de isolamento deste composto como produto natural. Do cultivo deste endófito, em meio de milho, foram isolado... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Endophytic fungi represent a promising source for the discovery of natural products. These endophytes have been shown to be highly capable of producing various classes of secondary metabolites with a wide variety of biological activities such as antimicrobial, cytotoxic, antioxidant, anxiolytic and insecticide. These observations motivated the development of the present study, which aimed at the chemical and biological prospecting of endophytic fungi associated with Platonia insignis Mart. The isolation of endophytic fungi resulted in eighteen pure strains, which were cultivated in liquid medium of PDB, to obtain the respective crude extracts. These extracts were evaluated for chemical and biological profile, which show promise for bioactive substances production. The initial prospecting led to the selection of two endophytic fungi, identified as Diaporthe hongkongensis and Phyllosticta elongata to develop the work. Two approaches were applied to verify the influence of nutritional composition on the metabolic production of D. hongkongensis and P. elongata: cultivation in PDB medium and cultivation in solid corn medium. The study of D. hongkongensis grown in PDB resulted in the isolation of a diketopiperazine, arylethylamide, acetyltryptamine and methyl [2-oxo-2- (phenylethylamino)] acetate, being the first report of isolation of this compound as a natural product. From the cultivation of this endophyte in corn medium, alternariol, a fatty acid ester and four steroids, which ... (Complete abstract click electronic access below) / Doutor