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Registro Completo |
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Biblioteca(s): |
Embrapa Agrobiologia. |
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Data corrente: |
10/10/2005 |
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Data da última atualização: |
14/05/2014 |
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Autoria: |
DE SOUZA, F. A. |
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Título: |
Biology, ecology and evolution of the family Gigasporaceae, arbuscular mycorrhizal fungi (Glomeromycota). |
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Ano de publicação: |
2005 |
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Fonte/Imprenta: |
2005. 157 p. Tese (Doutorado) - Universiteit Leiden, Netherlands. |
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Idioma: |
Inglês |
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Conteúdo: |
Research described in this thesis focused on biological, ecological and evolutionary aspects of Arbuscular Mycorrhizal Fungi (AMF), and in particular of the family Gigasporaceae (Gigaspora and Scutellospora, genera). This study had two major objectives. The first objective was to obtain better knowledge about the life history strategies (LHS) of Gigasporaceae, and the second objective was to study the intragenomic polymorphism of the ribosomal rDNA copies in order to understant its origin and to test the use of such polymorphism to discriminate between closely related species. The LHS patterns observed for the Gigasporaceae species studied suggests that they behave like K-strategists, i.e. organisms adapted to live at stable and predictable environments, as compared to Glomeraceae species that form single spores in the soil. Based on LHS patterns of Gigasporaceae an hypotheses that those species will be negatively selected in disturbed ecosystems have been formulated. Although intraspecific rDNA polymorphism in Gigasporaceae has been previously reported, this study, for the first time, systematically describes this heterogeneity and analyses this phenomenon with respect to Gigasporaceae phylogeny and evolution. It has been demonstrated that the intragenomic polymorphism of the rDNA copies can be used to differentiate species and in the case Gigaspora even islates. The phylogenetic analysis of inter and intragenomic rDNA polymorphism of closely related Gigaspora species strongly suggested that reticulated evolution, characterized by occasional hybridization or horizontal gene transfer betwwen two species, played a significant role in evolution of this asexual group of fungi, via parasexual recombination. In addition, a molecular method was developed assess
Gigasporaceae diversity in environmental samples.
Het onderzoek, dat in dit proefschrift is beschreven, was gericht op de biologische, ecologische en evolutionaire aspecten van arbusculaire mycorriza schimmels, AMF, en in het bijonder shimmels die behoren tot de famile van de Gigasporaceae (de soorten Gigaspora and Scutellospora). De voornaamste twee doeleinden van deze studie waren: 1) om een Kennis te verwerven van de 'Life History Strategies'2) om een beter begrip te krijgen van de oorsprong van het intragenomishe polymorfisme van het ribosomale DNA, om daarmee een methode te ontwikkelen om nauw verwante soorten te kunnen onderscheiden.
Het LHS patroon van de onderzochet leden van de famile van de Gigasporaceae duidt erop dat zij zich gedragen als typische K-strategen, oftewel organismen die zijn aangepast aan stabiele en voorspelbare milieu's, in tegenstelling tot de andere belangrijke mycorrhiza famile van de Glomeraceae soorten. Gebaseerd op LHS patronen van Gigasporaceae is de hypothese geformuleerd, dat die soorten negatief geselecteerd zullen worden in verstoorde ecosystemen. Ofschoon intragenomisch polymorfisme al eerder voor Gigasporaceae is gerapporteerd, is in dit onderzoek voorde eerste keer op systematische wijke deze heterogeniteit beschreven en is dit verschijnsel geanalyseerd in relatie tot de fylogenie en evolutie van Gigasporaceae. Aagetoond is dat het intragenomische polymorfisme van rDNA gebruikt kan worden om verschillende soorten en zelfs isolaten van Gigasporaceae te onderscheiden. De fylogenetische analyse van het inter en intragenomisch polymorfisme van nauw verwante Gigaspora soorten wijst er sterk op dat 'reticulated' evolutie, gekenmerkt door hybridisatie of horisontale gen overdracht tussen twee soorten, een doorslaggevende rol heeft gespeeld in de evolutie van deze groep van aseksuele via paraseksuele recombinatie. Voorts werd een ontwikked om de diversiteit van Gigasporaceae in de bodem te kunnen bepalen.
A pesquisa descrita nesta tese focou aspectos biológicos, e evolutivos de fungos Micorrízicos Arbusculares (FMA) e em particular a família Gigasporaceae (gênero Gigaspora e Scutellospora). Este estudo teve dois objetivos principais. O primeiro objetivo foi avançar o conhecimento sobre histórico de estratégia de vida (HEV) em Gigasporaceae, e o segundo objetivo foi estudar o polimorfismo intra-genômico do ribossomo rDNA visando elucidar sua origem e testar o uso deste polimorfismo para discriminar entre espécies próximas. Os padrões de HEV observados para as espécies de Gigasporaceae estudadas sugerem que elas se comportam como estrategistas em K, i.e. organismos adaptados a viverem em ambientes estáveis e previsíveis, quando comparado com espécies da família Glomeraceae que formam esporos isolados no solo. Baseado no padrão de HVE de Gigasporaceae foi formulada uma hipótese de que esta espécies serão selecionadas negativamente em ecossistemas perturbados. Embora, a ocorrência de polimorfismo intra-específico no rDNA tenha sido demostrado anteriormente, pela primeira vez, está heterogeneidade foi sistematicamente descrita e este fenômeno analisado em relação à filogenia e evolução da Gigasporaceae. Foi demonstrada que o polimorfismo intra-específico das copias do rDNA pode ser utilizado para diferenciar espécies e no caso de Gigaspora até isolados geográficos de uma mesma espécies. A análise filogenética do polimorfismo do rDNA intra e entre genomas de espécies de Gigaspora sugere claramente que a ocorrência de evolução reticular, caracterizada por hibridizações ocasionais e transferência horizontal de genes entre espécies, tiveram um papel significativo na evolução deste grupo de fungos assexuados, via recombinação parasexual. Além disso, um método molecular para acessar a diversidade de Gigasporaceae em amostras ambientais foi desenvolvido. MenosResearch described in this thesis focused on biological, ecological and evolutionary aspects of Arbuscular Mycorrhizal Fungi (AMF), and in particular of the family Gigasporaceae (Gigaspora and Scutellospora, genera). This study had two major objectives. The first objective was to obtain better knowledge about the life history strategies (LHS) of Gigasporaceae, and the second objective was to study the intragenomic polymorphism of the ribosomal rDNA copies in order to understant its origin and to test the use of such polymorphism to discriminate between closely related species. The LHS patterns observed for the Gigasporaceae species studied suggests that they behave like K-strategists, i.e. organisms adapted to live at stable and predictable environments, as compared to Glomeraceae species that form single spores in the soil. Based on LHS patterns of Gigasporaceae an hypotheses that those species will be negatively selected in disturbed ecosystems have been formulated. Although intraspecific rDNA polymorphism in Gigasporaceae has been previously reported, this study, for the first time, systematically describes this heterogeneity and analyses this phenomenon with respect to Gigasporaceae phylogeny and evolution. It has been demonstrated that the intragenomic polymorphism of the rDNA copies can be used to differentiate species and in the case Gigaspora even islates. The phylogenetic analysis of inter and intragenomic rDNA polymorphism of closely related Gigaspora species str... Mostrar Tudo |
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Palavras-Chave: |
Anatytical methods; Biology; Chemistry analytical; Evolução. |
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Thesagro: |
Análise Química; Biologia; Cenoura; Ecologia; Eletroforese; Micorriza Vesicular Arbuscular. |
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Thesaurus Nal: |
carrots; ecology; electrophoresis; evolution; vesicular arbuscular mycorrhizae. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 06531nam a2200289 a 4500
001 1622537
005 2014-05-14
008 2005 bl uuuu m 00u1 u #d
100 1 $aDE SOUZA, F. A.
245 $aBiology, ecology and evolution of the family Gigasporaceae, arbuscular mycorrhizal fungi (Glomeromycota).
260 $a2005. 157 p. Tese (Doutorado) - Universiteit Leiden, Netherlands.$c2005
520 $aResearch described in this thesis focused on biological, ecological and evolutionary aspects of Arbuscular Mycorrhizal Fungi (AMF), and in particular of the family Gigasporaceae (Gigaspora and Scutellospora, genera). This study had two major objectives. The first objective was to obtain better knowledge about the life history strategies (LHS) of Gigasporaceae, and the second objective was to study the intragenomic polymorphism of the ribosomal rDNA copies in order to understant its origin and to test the use of such polymorphism to discriminate between closely related species. The LHS patterns observed for the Gigasporaceae species studied suggests that they behave like K-strategists, i.e. organisms adapted to live at stable and predictable environments, as compared to Glomeraceae species that form single spores in the soil. Based on LHS patterns of Gigasporaceae an hypotheses that those species will be negatively selected in disturbed ecosystems have been formulated. Although intraspecific rDNA polymorphism in Gigasporaceae has been previously reported, this study, for the first time, systematically describes this heterogeneity and analyses this phenomenon with respect to Gigasporaceae phylogeny and evolution. It has been demonstrated that the intragenomic polymorphism of the rDNA copies can be used to differentiate species and in the case Gigaspora even islates. The phylogenetic analysis of inter and intragenomic rDNA polymorphism of closely related Gigaspora species strongly suggested that reticulated evolution, characterized by occasional hybridization or horizontal gene transfer betwwen two species, played a significant role in evolution of this asexual group of fungi, via parasexual recombination. In addition, a molecular method was developed assess Gigasporaceae diversity in environmental samples. Het onderzoek, dat in dit proefschrift is beschreven, was gericht op de biologische, ecologische en evolutionaire aspecten van arbusculaire mycorriza schimmels, AMF, en in het bijonder shimmels die behoren tot de famile van de Gigasporaceae (de soorten Gigaspora and Scutellospora). De voornaamste twee doeleinden van deze studie waren: 1) om een Kennis te verwerven van de 'Life History Strategies'2) om een beter begrip te krijgen van de oorsprong van het intragenomishe polymorfisme van het ribosomale DNA, om daarmee een methode te ontwikkelen om nauw verwante soorten te kunnen onderscheiden. Het LHS patroon van de onderzochet leden van de famile van de Gigasporaceae duidt erop dat zij zich gedragen als typische K-strategen, oftewel organismen die zijn aangepast aan stabiele en voorspelbare milieu's, in tegenstelling tot de andere belangrijke mycorrhiza famile van de Glomeraceae soorten. Gebaseerd op LHS patronen van Gigasporaceae is de hypothese geformuleerd, dat die soorten negatief geselecteerd zullen worden in verstoorde ecosystemen. Ofschoon intragenomisch polymorfisme al eerder voor Gigasporaceae is gerapporteerd, is in dit onderzoek voorde eerste keer op systematische wijke deze heterogeniteit beschreven en is dit verschijnsel geanalyseerd in relatie tot de fylogenie en evolutie van Gigasporaceae. Aagetoond is dat het intragenomische polymorfisme van rDNA gebruikt kan worden om verschillende soorten en zelfs isolaten van Gigasporaceae te onderscheiden. De fylogenetische analyse van het inter en intragenomisch polymorfisme van nauw verwante Gigaspora soorten wijst er sterk op dat 'reticulated' evolutie, gekenmerkt door hybridisatie of horisontale gen overdracht tussen twee soorten, een doorslaggevende rol heeft gespeeld in de evolutie van deze groep van aseksuele via paraseksuele recombinatie. Voorts werd een ontwikked om de diversiteit van Gigasporaceae in de bodem te kunnen bepalen. A pesquisa descrita nesta tese focou aspectos biológicos, e evolutivos de fungos Micorrízicos Arbusculares (FMA) e em particular a família Gigasporaceae (gênero Gigaspora e Scutellospora). Este estudo teve dois objetivos principais. O primeiro objetivo foi avançar o conhecimento sobre histórico de estratégia de vida (HEV) em Gigasporaceae, e o segundo objetivo foi estudar o polimorfismo intra-genômico do ribossomo rDNA visando elucidar sua origem e testar o uso deste polimorfismo para discriminar entre espécies próximas. Os padrões de HEV observados para as espécies de Gigasporaceae estudadas sugerem que elas se comportam como estrategistas em K, i.e. organismos adaptados a viverem em ambientes estáveis e previsíveis, quando comparado com espécies da família Glomeraceae que formam esporos isolados no solo. Baseado no padrão de HVE de Gigasporaceae foi formulada uma hipótese de que esta espécies serão selecionadas negativamente em ecossistemas perturbados. Embora, a ocorrência de polimorfismo intra-específico no rDNA tenha sido demostrado anteriormente, pela primeira vez, está heterogeneidade foi sistematicamente descrita e este fenômeno analisado em relação à filogenia e evolução da Gigasporaceae. Foi demonstrada que o polimorfismo intra-específico das copias do rDNA pode ser utilizado para diferenciar espécies e no caso de Gigaspora até isolados geográficos de uma mesma espécies. A análise filogenética do polimorfismo do rDNA intra e entre genomas de espécies de Gigaspora sugere claramente que a ocorrência de evolução reticular, caracterizada por hibridizações ocasionais e transferência horizontal de genes entre espécies, tiveram um papel significativo na evolução deste grupo de fungos assexuados, via recombinação parasexual. Além disso, um método molecular para acessar a diversidade de Gigasporaceae em amostras ambientais foi desenvolvido.
650 $acarrots
650 $aecology
650 $aelectrophoresis
650 $aevolution
650 $avesicular arbuscular mycorrhizae
650 $aAnálise Química
650 $aBiologia
650 $aCenoura
650 $aEcologia
650 $aEletroforese
650 $aMicorriza Vesicular Arbuscular
653 $aAnatytical methods
653 $aBiology
653 $aChemistry analytical
653 $aEvolução
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Embrapa Agrobiologia (CNPAB) |
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