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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Genetic diversity of Vetiver clones (Chrysopogon zizanioides and Chrysopogon nigritana) available in South Africa based on sequencing analyses and anatomical structure / Vickey Diedericks

Diedericks, Vickey January 2014 (has links)
Vetiver grass or Chrysopogon zizanioides (L.) Roberty (1960) is a sterile grass which can regenerate vegetatively from clumps of the rootstock. This, as well as its vigorous and deep root system and flood tolerance makes it an ideal candidate for the use in soil remediation and erosion control. In South Africa, Hydromulch (Pty) Ltd. is part of the landscape, soil reclamation and erosion control industry. The company uses vetiver grass on a wide scale and has accumulated a collection of isolates to serve as possible germ lines for industrial use. Due to the different approaches in environmental management as well as environmental factors, a variety of ecotypes form during the planting and acclimatisation of this genus. Chrysopogon nigritanus (Benth.) Veldkamp (1999), which is a native species to Africa, is closely related to C. zizanioides and differs only slightly from C. zizanioides on a morphological level. The major difference between the two species is that C. nigritanus is able to seed freely and thus the use of this species should be avoided. The need arose to screen other non-fertile plants to uncover additional genotypic variety to enable diversification of vetiver plantings. The aim of this study was to characterise the genotype of 19 isolates of vetiver obtained from Hydromulch (Pty) Ltd. via sequencing analyses of three DNA fragments, ITS, ndhF and rbcL. In addition, the radial root anatomy was also investigated and compared with the genetic analyses. According to the results generated during this study, very little or no genotypical differences exist amongst the different isolates available from the Hydromulch (Pty) Ltd. plant collection. Only in the case of the ITS inference were differences observed between three of the studied isolates. There was no significant difference between the different isolates based on the root anatomy, with the exception of two of the studied isolates which formed starch granules. / MSc (Botany), North-West University, Potchefstroom Campus, 2014
2

Genetic diversity of Vetiver clones (Chrysopogon zizanioides and Chrysopogon nigritana) available in South Africa based on sequencing analyses and anatomical structure / Vickey Diedericks

Diedericks, Vickey January 2014 (has links)
Vetiver grass or Chrysopogon zizanioides (L.) Roberty (1960) is a sterile grass which can regenerate vegetatively from clumps of the rootstock. This, as well as its vigorous and deep root system and flood tolerance makes it an ideal candidate for the use in soil remediation and erosion control. In South Africa, Hydromulch (Pty) Ltd. is part of the landscape, soil reclamation and erosion control industry. The company uses vetiver grass on a wide scale and has accumulated a collection of isolates to serve as possible germ lines for industrial use. Due to the different approaches in environmental management as well as environmental factors, a variety of ecotypes form during the planting and acclimatisation of this genus. Chrysopogon nigritanus (Benth.) Veldkamp (1999), which is a native species to Africa, is closely related to C. zizanioides and differs only slightly from C. zizanioides on a morphological level. The major difference between the two species is that C. nigritanus is able to seed freely and thus the use of this species should be avoided. The need arose to screen other non-fertile plants to uncover additional genotypic variety to enable diversification of vetiver plantings. The aim of this study was to characterise the genotype of 19 isolates of vetiver obtained from Hydromulch (Pty) Ltd. via sequencing analyses of three DNA fragments, ITS, ndhF and rbcL. In addition, the radial root anatomy was also investigated and compared with the genetic analyses. According to the results generated during this study, very little or no genotypical differences exist amongst the different isolates available from the Hydromulch (Pty) Ltd. plant collection. Only in the case of the ITS inference were differences observed between three of the studied isolates. There was no significant difference between the different isolates based on the root anatomy, with the exception of two of the studied isolates which formed starch granules. / MSc (Botany), North-West University, Potchefstroom Campus, 2014
3

Filogenia molecular do gênero Dolichandra s.l. (Bignonieae, Bignoniaceae) / Molecular phylogeny of the genus Dolichandra s.l. (Bignonieae, Bignoniaceae)

Fonseca, Luiz Henrique Martins 01 November 2012 (has links)
Dolichandra s.l. é um gênero de lianas com distribuição neotropical pertencente a família Bignoniaceae, tribo Bignonieae. A atual circunscrição do gênero foi estabelecida com base em uma filogenia molecular da tribo, a qual foi interpretada a luz de caracteres morfológicos. Atualmente são reconhecidas 10 espécies, duas delas propostas nesta dissertação. Espécies de Dolichandra s.l. apresentam grande variação em sua distribuição geográfica e habitats ocupados, bem como em caracteres morfológicos relacionados aos sistemas de polinização e dispersão. O presente estudo teve como objetivos: (1) reconstruir a filogenia de Dolichandra s.l. utilizando os marcadores moleculares plastidiais ndhF e rps32-trnL e o marcador nuclear PepC, e (2) utilizar a filogenia como base para inferir os processos que atuaram na especiação do gênero. Amostras de quatro grupos externos e 20 indivíduos de Dolichandra s.l. foram obtidas, totalizando nove de Dolichandra s.l. Filogenias bem resolvidas para os três marcadores amostrados revelaram que tanto o gênero, como as espécies com mais de um indvíduo amostrados são monofiléticas. Dolichandra unguiculata é a primeira linhagem à divergir dentro da família, sendo grupo-irmão das demais espécies do gênero em todas as topologias. Dolichandra acuminata e D. quadrivalvis formam um clado bem sustentado em todas as topologias. Esse clado emergiu para todos os marcadores e critérios de reconstrução como irmão do clado formado por D. dentata, D. hispida, D. uncata e D. unguis-cati. Nesse último clado, D. uncata sempre aparece como irmã das espécies restantes em todas as topologias. Por outro lado, o posicionamento de D. chodatii, D. cynanchoides, D. dentata e D. híspida não está bem sustentado na árvore combinada, refletindo diferenças na topologia entre os marcadores plastidiais e o marcador nuclear. Todos os nós da filogenia apresentam algum grau de simpatria entre suas linhagens, indicando a importância da diferenciação de nichos para a diversificação do gênero e a prevalência de especiação simpátrica no grupo. / Dolichandra s.l. is a genus of lianas found in the Neotropics. It belongs to the family Bignoniaceae, tribe Bignonieae. The actual circumscription of the genus was based on a molecular phylogeny of the tribe and morphological synanpomorphies. Currently the genus comprises ten species, two of than proposed in this dissertation. Species of Dolichandra s.l. have great variation in geographic distribution, habitats occupied, as well as, morphological characters related to pollination and dispersal events. The goals of this study are: (1) Reconstruct the phylogeny of Dolichandra s.l. using the plastid markers ndhF e rps32-trnL and the nuclear marker PepC, and (2) use the phylogeny as base to infer process that acted in genus diversification. A sample from four outgroups and 20 individuals were obtained, accounting nine species of Dolichandra s.l. Well resolved phylogenies for the three markers revealed that the genus, and the multiple sampled species are monophyletic. Dolichandra unguiculata is the first species to diverge, being sister of a clade with the rest of the genus in all topologies. Dolichandra acuminate as sister of D. quadrivalvis is a well supported clade in all topologies. This clade emerged for all markers and criteria as sister of clade with D. dentata, D. hispida, D. uncata, and D. unguis-cati. In the latter clade, D. uncata emerged as sister of the other species in all topologies. On the other hand, the phylognetic position of D. chodatii, D. cynanchoides, D. dentate and D. hispida is not well supported in the combined analysis, revealing differences in topology between plastid and nuclear markers. All the nodes of the phylogeny have some degree of sympatry between lineages, indicating the importance of niche differences for the genus diversification and the prevalence of sympatric speciation.
4

Avaliação toxicogenética e ecotoxicológica de corantes têxteis / Toxicogenetic and ecotoxicological assessment of textile dyes

Oliveira, Gisele Augusto Rodrigues de 12 June 2013 (has links)
O tingimento de tecidos começou há milhares de anos e a disponibilidade comercial de corantes é enorme e crescente. A indústria têxtil brasileira desempenha um papel de inquestionável importância, destacando-se entre as principais atividades econômicas do país. O processo de tingimento é um dos fatores fundamentais no sucesso comercial dos produtos têxteis, uma vez que o consumidor exige cores resistentes à exposição ao calor, à luz, à transpiração e às lavagens. Segundo a literatura, condições de transpiração intensa contribuem para uma alta taxa de migração e subseqüente penetração de corantes têxteis para a pele humana. Além disso, 2 a 50% desses compostos permanecem no banho de tingimento e são descartados nos efluentes industriais, contaminando o ambiente e colocando em risco a saúde humana, uma vez que os métodos convencionais de tratamento de efluentes são ineficientes na remoção da coloração e da mutagenicidade de alguns corantes. Dentro deste contexto, este trabalho teve como objetivo avaliar os efeitos toxicogenéticos do corante Direct Black (DB38) original e após extração por lixiviação com suor sintético, utilizando o teste do cometa com fibroblastos e queratinócitos de pele humana, o teste Anexina V com fibroblastos e o ensaio de mutagenicidade com Salmonella typhimurium. Adicionalmente, foi investigada a ecotoxicidade dos corantes têxteis Direct Black 38 e Reactive Blue 15 (RB15) originais por meio de ensaios com sementes, dapnhias, minhocas e zebrafish realizados na UTOX, em Barcelona. O corante DB38 original e lixiviado não induziram genotoxicidade em fibroblastos e queratinócitos de pele humana. O corante DB38 original foi mutagênico para as linhagens TA98 e TA100 de S. typhimurium na presença de S9. Entretanto, o corante lixiviado não induziu mutagenicidade para essas linhagens testadas, considerando que a maior taxa de migração do corante para a solução de suor foi de ~1% nas seguintes condições: tingimento sem ensaboamento, pH 8,0 e 8 horas de incubação à 42°C. O corante original é citotóxico para fibroblastos após 48 horas de exposição. No entanto, essa citotoxicidade não foi mais observada após a lixiviação no suor. Os corantes DB38 e RB15 originais não foram tóxicos para as sementes de pepino, alface e tomate, e nem para as minhocas Eisenia foetida. Ambos os corantes foram fracamente tóxicos para Daphnia magna, porém o RB15 apresenta maior potencial tóxico em relação ao DB38. Os corantes DB38 e RB15 induziram malformações em larvas de zebrafish Danio rerio, caracterizadas por falha na inflação da bexiga natatória e alteração na cauda. Portanto, nossos resultados mostram a importância de se fazer não só a análise individual de corantes têxteis, mas também dos tecidos que os contêm. Além da necessidade de se desenvolver técnicas de tingimento mais seguras em relação à solidez da cor sob condições úmidas e as perdas de corante para o ambiente durante a etapa de fixação, indicando maior atenção ao estudo de efeitos sub-letais na avaliação do impacto desses compostos no ecossistema aquático. / The fabrics dyeing began thousands of years ago and the commercial availability of dyes is increasingly. The Brazilian textile industry plays a role of high importance, highlighting among the main economic activities in the country. The dyeing process is one of the key factors in the commercial success of textile products, since consumers are demanding colors more resistant to heat, light exposure, perspiration and washing. According to the literature, conditions of intense perspiration contribute to the migration and subsequent penetration of textile dyes to human skin. Furthermore, 2 to 50% of the initial dye load is present in the dye bath effluent and these compounds are discharged in industrial effluents, contaminating the environment and endangering human health, since the wastewater treatment systems are ineffective in removing the color and mutagenicity of some dyes. In this context, this study aimed to evaluate the toxicogenetic effects of the Direct Black 38 (DB38) dye original and extracted by leaching with artificial sweat using Comet assay with fibroblasts and keratinocytes from human skin, Anexin V assay with fibroblasts and Salmonella mutagenicity test. Additionally, we investigated the ecotoxicity of textile dye Direct Black 38 and Reactive Blue 15 (RB15) using assays with seeds, dapnhias, worms and zebrafish performed in UTOX in Barcelona. The original and leached DB38 dye did not induce genotoxicity in fibroblasts and keratinocytes from human skin. The original DB38 was mutagenic for TA98 and TA100 of S. typhimurium with S9. However, the solution with the leached dye did not induce mutagenicity for these tested strains, since the highest migration rate of the dye to the solution of artificial sweat was ~ 1% in the following conditions: type of dyeing without rinsing, pH 8.0 and 8-hour incubation at 42°C. The original dye was cytotoxic for fibroblasts after 48 hours of exposure. However, this cytotoxicity was no longer observed after leaching in sweat. The original DB38 and RB15 dyes showed no toxicity for cucumber, lettuce and tomato seeds and for earthworms Eisenia foetida. Both dyes were weakly toxic for Daphnia magna, but the RB15 has a higher toxic potential compared to DB38. The dyes DB38 and RB15 induced malformations in larvae of zebrafish Danio rerio by failure of the swim bladder inflation and changes in the tail. Therefore, our results show the importance of making the individual analysis of textile dyes, but also of fabrics containing them. Furthermore, it is necessary to develop safer techniques of dyeing in relation to the color fastness under humid conditions and the loss of dyes into the environment during the fixation step, indicating more attention to the study of sub-lethal effects in the evaluation of the impact of these compounds in the aquatic ecosystem.
5

Avaliação toxicogenética e ecotoxicológica de corantes têxteis / Toxicogenetic and ecotoxicological assessment of textile dyes

Gisele Augusto Rodrigues de Oliveira 12 June 2013 (has links)
O tingimento de tecidos começou há milhares de anos e a disponibilidade comercial de corantes é enorme e crescente. A indústria têxtil brasileira desempenha um papel de inquestionável importância, destacando-se entre as principais atividades econômicas do país. O processo de tingimento é um dos fatores fundamentais no sucesso comercial dos produtos têxteis, uma vez que o consumidor exige cores resistentes à exposição ao calor, à luz, à transpiração e às lavagens. Segundo a literatura, condições de transpiração intensa contribuem para uma alta taxa de migração e subseqüente penetração de corantes têxteis para a pele humana. Além disso, 2 a 50% desses compostos permanecem no banho de tingimento e são descartados nos efluentes industriais, contaminando o ambiente e colocando em risco a saúde humana, uma vez que os métodos convencionais de tratamento de efluentes são ineficientes na remoção da coloração e da mutagenicidade de alguns corantes. Dentro deste contexto, este trabalho teve como objetivo avaliar os efeitos toxicogenéticos do corante Direct Black (DB38) original e após extração por lixiviação com suor sintético, utilizando o teste do cometa com fibroblastos e queratinócitos de pele humana, o teste Anexina V com fibroblastos e o ensaio de mutagenicidade com Salmonella typhimurium. Adicionalmente, foi investigada a ecotoxicidade dos corantes têxteis Direct Black 38 e Reactive Blue 15 (RB15) originais por meio de ensaios com sementes, dapnhias, minhocas e zebrafish realizados na UTOX, em Barcelona. O corante DB38 original e lixiviado não induziram genotoxicidade em fibroblastos e queratinócitos de pele humana. O corante DB38 original foi mutagênico para as linhagens TA98 e TA100 de S. typhimurium na presença de S9. Entretanto, o corante lixiviado não induziu mutagenicidade para essas linhagens testadas, considerando que a maior taxa de migração do corante para a solução de suor foi de ~1% nas seguintes condições: tingimento sem ensaboamento, pH 8,0 e 8 horas de incubação à 42°C. O corante original é citotóxico para fibroblastos após 48 horas de exposição. No entanto, essa citotoxicidade não foi mais observada após a lixiviação no suor. Os corantes DB38 e RB15 originais não foram tóxicos para as sementes de pepino, alface e tomate, e nem para as minhocas Eisenia foetida. Ambos os corantes foram fracamente tóxicos para Daphnia magna, porém o RB15 apresenta maior potencial tóxico em relação ao DB38. Os corantes DB38 e RB15 induziram malformações em larvas de zebrafish Danio rerio, caracterizadas por falha na inflação da bexiga natatória e alteração na cauda. Portanto, nossos resultados mostram a importância de se fazer não só a análise individual de corantes têxteis, mas também dos tecidos que os contêm. Além da necessidade de se desenvolver técnicas de tingimento mais seguras em relação à solidez da cor sob condições úmidas e as perdas de corante para o ambiente durante a etapa de fixação, indicando maior atenção ao estudo de efeitos sub-letais na avaliação do impacto desses compostos no ecossistema aquático. / The fabrics dyeing began thousands of years ago and the commercial availability of dyes is increasingly. The Brazilian textile industry plays a role of high importance, highlighting among the main economic activities in the country. The dyeing process is one of the key factors in the commercial success of textile products, since consumers are demanding colors more resistant to heat, light exposure, perspiration and washing. According to the literature, conditions of intense perspiration contribute to the migration and subsequent penetration of textile dyes to human skin. Furthermore, 2 to 50% of the initial dye load is present in the dye bath effluent and these compounds are discharged in industrial effluents, contaminating the environment and endangering human health, since the wastewater treatment systems are ineffective in removing the color and mutagenicity of some dyes. In this context, this study aimed to evaluate the toxicogenetic effects of the Direct Black 38 (DB38) dye original and extracted by leaching with artificial sweat using Comet assay with fibroblasts and keratinocytes from human skin, Anexin V assay with fibroblasts and Salmonella mutagenicity test. Additionally, we investigated the ecotoxicity of textile dye Direct Black 38 and Reactive Blue 15 (RB15) using assays with seeds, dapnhias, worms and zebrafish performed in UTOX in Barcelona. The original and leached DB38 dye did not induce genotoxicity in fibroblasts and keratinocytes from human skin. The original DB38 was mutagenic for TA98 and TA100 of S. typhimurium with S9. However, the solution with the leached dye did not induce mutagenicity for these tested strains, since the highest migration rate of the dye to the solution of artificial sweat was ~ 1% in the following conditions: type of dyeing without rinsing, pH 8.0 and 8-hour incubation at 42°C. The original dye was cytotoxic for fibroblasts after 48 hours of exposure. However, this cytotoxicity was no longer observed after leaching in sweat. The original DB38 and RB15 dyes showed no toxicity for cucumber, lettuce and tomato seeds and for earthworms Eisenia foetida. Both dyes were weakly toxic for Daphnia magna, but the RB15 has a higher toxic potential compared to DB38. The dyes DB38 and RB15 induced malformations in larvae of zebrafish Danio rerio by failure of the swim bladder inflation and changes in the tail. Therefore, our results show the importance of making the individual analysis of textile dyes, but also of fabrics containing them. Furthermore, it is necessary to develop safer techniques of dyeing in relation to the color fastness under humid conditions and the loss of dyes into the environment during the fixation step, indicating more attention to the study of sub-lethal effects in the evaluation of the impact of these compounds in the aquatic ecosystem.
6

Filogenia molecular do gênero Dolichandra s.l. (Bignonieae, Bignoniaceae) / Molecular phylogeny of the genus Dolichandra s.l. (Bignonieae, Bignoniaceae)

Luiz Henrique Martins Fonseca 01 November 2012 (has links)
Dolichandra s.l. é um gênero de lianas com distribuição neotropical pertencente a família Bignoniaceae, tribo Bignonieae. A atual circunscrição do gênero foi estabelecida com base em uma filogenia molecular da tribo, a qual foi interpretada a luz de caracteres morfológicos. Atualmente são reconhecidas 10 espécies, duas delas propostas nesta dissertação. Espécies de Dolichandra s.l. apresentam grande variação em sua distribuição geográfica e habitats ocupados, bem como em caracteres morfológicos relacionados aos sistemas de polinização e dispersão. O presente estudo teve como objetivos: (1) reconstruir a filogenia de Dolichandra s.l. utilizando os marcadores moleculares plastidiais ndhF e rps32-trnL e o marcador nuclear PepC, e (2) utilizar a filogenia como base para inferir os processos que atuaram na especiação do gênero. Amostras de quatro grupos externos e 20 indivíduos de Dolichandra s.l. foram obtidas, totalizando nove de Dolichandra s.l. Filogenias bem resolvidas para os três marcadores amostrados revelaram que tanto o gênero, como as espécies com mais de um indvíduo amostrados são monofiléticas. Dolichandra unguiculata é a primeira linhagem à divergir dentro da família, sendo grupo-irmão das demais espécies do gênero em todas as topologias. Dolichandra acuminata e D. quadrivalvis formam um clado bem sustentado em todas as topologias. Esse clado emergiu para todos os marcadores e critérios de reconstrução como irmão do clado formado por D. dentata, D. hispida, D. uncata e D. unguis-cati. Nesse último clado, D. uncata sempre aparece como irmã das espécies restantes em todas as topologias. Por outro lado, o posicionamento de D. chodatii, D. cynanchoides, D. dentata e D. híspida não está bem sustentado na árvore combinada, refletindo diferenças na topologia entre os marcadores plastidiais e o marcador nuclear. Todos os nós da filogenia apresentam algum grau de simpatria entre suas linhagens, indicando a importância da diferenciação de nichos para a diversificação do gênero e a prevalência de especiação simpátrica no grupo. / Dolichandra s.l. is a genus of lianas found in the Neotropics. It belongs to the family Bignoniaceae, tribe Bignonieae. The actual circumscription of the genus was based on a molecular phylogeny of the tribe and morphological synanpomorphies. Currently the genus comprises ten species, two of than proposed in this dissertation. Species of Dolichandra s.l. have great variation in geographic distribution, habitats occupied, as well as, morphological characters related to pollination and dispersal events. The goals of this study are: (1) Reconstruct the phylogeny of Dolichandra s.l. using the plastid markers ndhF e rps32-trnL and the nuclear marker PepC, and (2) use the phylogeny as base to infer process that acted in genus diversification. A sample from four outgroups and 20 individuals were obtained, accounting nine species of Dolichandra s.l. Well resolved phylogenies for the three markers revealed that the genus, and the multiple sampled species are monophyletic. Dolichandra unguiculata is the first species to diverge, being sister of a clade with the rest of the genus in all topologies. Dolichandra acuminate as sister of D. quadrivalvis is a well supported clade in all topologies. This clade emerged for all markers and criteria as sister of clade with D. dentata, D. hispida, D. uncata, and D. unguis-cati. In the latter clade, D. uncata emerged as sister of the other species in all topologies. On the other hand, the phylognetic position of D. chodatii, D. cynanchoides, D. dentate and D. hispida is not well supported in the combined analysis, revealing differences in topology between plastid and nuclear markers. All the nodes of the phylogeny have some degree of sympatry between lineages, indicating the importance of niche differences for the genus diversification and the prevalence of sympatric speciation.
7

Phylogenetic Studies in the Gentianales – Approaches at Different Taxonomic Levels

Backlund, Maria January 2005 (has links)
This thesis deals with phylogenetic relationships at different taxonomic levels. All the plants studied are or have been included in the order Gentianales, which comprises about 17 200 species. The phylogenies are based on parsimony analyses of nucleotide sequence data (DNA) from different regions in the chloroplast genome, but morphological characteristics have also been studied. Analyses of sequence data from the genes rbcL and ndhF provide the interfamilial structure of the order Gentianales, shown to comprise the families Apocynaceae (incl. Asclepiadaceae), Gelsemiaceae, Gentianaceae, Loganiaceae, and Rubiaceae. Exclusion of certain genera from the Loganiaceae is confirmed and their phylogenetic positions are clarified. Some of these genera remain within the Gentianales, while others belong to other orders. Exclusion of the tribe Buddlejeae from the Loganiaceae is confirmed, and a monophyletic group formed by Buddleja, Emorya, Gomphostigma, and Nicodemia is recognized and placed in the Lamiales. The Loganiaceae s.str. forms, after these exclusions, a strongly supported monophyletic group comprising 13 genera. The tribe Paederieae in the family Rubiaceae is analysed using sequence data from the regions rbcL gene, rps16 intron, and the regions trnT-F, and is shown to be paraphyletic. These results lead to a new circumscription of Paederieae comprising the genera Leptodermis, Paederia, Serissa, and Spermadictyon. The tribe Putorieae is reestablished with the single genus Plocama, including 34 species. Aitchisonia, Choulettia, Crocyllis, Gaillonia, Jaubertia, Pseudogaillonia, Pterogaillonia, and Putoria are reduced to synonyms of Plocama based on the molecular analyses and morphological studies. The Mediterranean species of the re-circumscribed Plocama, previously segregated as the genus Putoria, are revised. Two species, Plocama calabrica and P. brevifolia, are recognized, their synonymics are established, and seven lectotypes are selected.

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