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Registro Completo |
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Biblioteca(s): |
Embrapa Soja. |
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Data corrente: |
08/04/2009 |
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Data da última atualização: |
15/02/2012 |
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Autoria: |
ALBERTON, O. |
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Título: |
Mycorrhizal responses under elevated CO² - combining fungal and plant perspectives. |
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Ano de publicação: |
2008 |
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Fonte/Imprenta: |
Wageningen: Wageningen University, 2008. |
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Páginas: |
148p. |
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ISBN: |
978-90-8504-910-4 |
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Idioma: |
Inglês |
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Conteúdo: |
The rising leveI of atmospheric carbon dioxide (C02) combined with increased nutrient (especially nitrogen) availability are predicted to have substantial impacts on plant growth and the functioning of ecosystems. Soil micro-organisms, especially mycorrhizal fungi that form mutualistic associations with plant roots, are key factors in the functioning of ecosystems. Studies of plant responses are therefore of limited realism, if the mycorrhizal symbiosis is ignored. It is therefore important to understand the diversity, extent and dynamics of the mycelia of mycorrhizal fungi in soils. This thesis focuses on the interactions between mycorrhizal fungi, mycorrhizal plants, elevated CO2, and nutrient availability. I consider mycorrhizal fungal and plant responses separately under elevated atmospheric CO2 to test a model that assumes that increased C availability to the fungus will not automatically feed back to enhanced plant growth performance. I use meta-analyses across independent studies and compare the responses of ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) fungi, and ECM and AM plants. Responses ofboth mycorrhizal fungi and myçorrhizal plants to elevated CO2 are significantly positive. Fractional colonization is an unsuitable fungal parameter to determine fungal responses to elevated CO2, at least for ECM systems. Fungal identity and plant identity are important parameters that are affected by elevated CO2. For ECM systems the data show the need for a conceptual separation of mycocentric and phytocentric perspectives, while for AM systems the responses ofboth partners are not significantly different. I performed an experiment to investigate fungal species-specific responses of ECM Scots pine (Pinus sylvestris) seedling growth and nutrient uptake together with mycelial development under N-limitation and different C availability. I observed that at elevated CO2 shoot-to-root ratio decreased, most strongly so in ECM species with the largest extraradical mycelium. Under elevated CO2, ECM root growth increased more than hyphal growth. Extraradical hyphal length was significantly negatively correlated with shoot biomass, SllOot N content and total plant N uptake. Fungal sink strength for N strongly affected plant growth through N immobilization. This mycorrhizal fungal-induced Progressive Nitrogen Limitation (PNL) has the potential to generate negative feedback with plant growth under elevated CO2o Following these results I investigated fungal species-specific responses of ECM Scots pine seedlings under ambient and elevated CO2 and under low and high N availability. Most plant and fungal parameters were significantly affected by fungal species, CO2 leveI and N supply. Under N limitation and at elevated CO2, a large part of photoassimilates were rapidly wasted in respiration through a mycorrhizal overflow CO2 tapo Increasing N availability potentially relieved mycorrhiza-induced PNL under elevated CO2. I also investigated the effects of different Dark Septate root Endophytic fungi (DSE) on growth and nutrient status of Scots pine seedlings because nothing was known about the direction and magnitude of their effects under conditions of N-limitation and elevated CO2. None of the DSE fungi caused mortality in the host. Under elevated CO2 plant biomass increased on average by 17% when inoculated with DSE. Shoot N concentration decreased by 57% under elevated CO2. Even though under elevated C02 and low N availability the length of extraradical hyphae increased by 53% and no evidence was found for significant N competition with the host. I conclude that the impact of DSE is more through improved nutrient use efficiency by the plant than through enhanced nutrient acquisition. Possibly, DSE react differently to global change than ECM fungi, indicating that there are limits to the degree of similarity in mutualistic function between both groups. In conc1usion, only under conditions where the amount of extraradical mycelium is sub-optimal from the perspective of plant nutrition, will increased mycelial biomass, induced by elevated CO2, be profitable for the plant. If, however, the amount of extraradical mycelium is already supra-optimal from a phytocentric perspective, further increases in C allocation to the fungus will increase fungar fitness but will not be profitable to the plant. Increased fungal fitness could then enhance PNL. The diversity among fungal species and their individual responses to CO2 and nutrient availability will therefore have a major impact on plant performance. My findings have therefore confirmed the need to conceptually separate mycocentric and phytocentric views. MenosThe rising leveI of atmospheric carbon dioxide (C02) combined with increased nutrient (especially nitrogen) availability are predicted to have substantial impacts on plant growth and the functioning of ecosystems. Soil micro-organisms, especially mycorrhizal fungi that form mutualistic associations with plant roots, are key factors in the functioning of ecosystems. Studies of plant responses are therefore of limited realism, if the mycorrhizal symbiosis is ignored. It is therefore important to understand the diversity, extent and dynamics of the mycelia of mycorrhizal fungi in soils. This thesis focuses on the interactions between mycorrhizal fungi, mycorrhizal plants, elevated CO2, and nutrient availability. I consider mycorrhizal fungal and plant responses separately under elevated atmospheric CO2 to test a model that assumes that increased C availability to the fungus will not automatically feed back to enhanced plant growth performance. I use meta-analyses across independent studies and compare the responses of ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) fungi, and ECM and AM plants. Responses ofboth mycorrhizal fungi and myçorrhizal plants to elevated CO2 are significantly positive. Fractional colonization is an unsuitable fungal parameter to determine fungal responses to elevated CO2, at least for ECM systems. Fungal identity and plant identity are important parameters that are affected by elevated CO2. For ECM systems the data show the need for a conceptual ... Mostrar Tudo |
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Palavras-Chave: |
Pinus silvestris. |
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Thesagro: |
Dióxido de Carbono; Fungo; Micorriza; Microrganismo; Nitrogênio; Pinheiro; Solo. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 05275nam a2200229 a 4500
001 1450427
005 2012-02-15
008 2008 bl uuuu 00u1 u #d
020 $a978-90-8504-910-4
100 1 $aALBERTON, O.
245 $aMycorrhizal responses under elevated CO² - combining fungal and plant perspectives.
260 $aWageningen: Wageningen University$c2008
300 $a148p.
520 $aThe rising leveI of atmospheric carbon dioxide (C02) combined with increased nutrient (especially nitrogen) availability are predicted to have substantial impacts on plant growth and the functioning of ecosystems. Soil micro-organisms, especially mycorrhizal fungi that form mutualistic associations with plant roots, are key factors in the functioning of ecosystems. Studies of plant responses are therefore of limited realism, if the mycorrhizal symbiosis is ignored. It is therefore important to understand the diversity, extent and dynamics of the mycelia of mycorrhizal fungi in soils. This thesis focuses on the interactions between mycorrhizal fungi, mycorrhizal plants, elevated CO2, and nutrient availability. I consider mycorrhizal fungal and plant responses separately under elevated atmospheric CO2 to test a model that assumes that increased C availability to the fungus will not automatically feed back to enhanced plant growth performance. I use meta-analyses across independent studies and compare the responses of ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) fungi, and ECM and AM plants. Responses ofboth mycorrhizal fungi and myçorrhizal plants to elevated CO2 are significantly positive. Fractional colonization is an unsuitable fungal parameter to determine fungal responses to elevated CO2, at least for ECM systems. Fungal identity and plant identity are important parameters that are affected by elevated CO2. For ECM systems the data show the need for a conceptual separation of mycocentric and phytocentric perspectives, while for AM systems the responses ofboth partners are not significantly different. I performed an experiment to investigate fungal species-specific responses of ECM Scots pine (Pinus sylvestris) seedling growth and nutrient uptake together with mycelial development under N-limitation and different C availability. I observed that at elevated CO2 shoot-to-root ratio decreased, most strongly so in ECM species with the largest extraradical mycelium. Under elevated CO2, ECM root growth increased more than hyphal growth. Extraradical hyphal length was significantly negatively correlated with shoot biomass, SllOot N content and total plant N uptake. Fungal sink strength for N strongly affected plant growth through N immobilization. This mycorrhizal fungal-induced Progressive Nitrogen Limitation (PNL) has the potential to generate negative feedback with plant growth under elevated CO2o Following these results I investigated fungal species-specific responses of ECM Scots pine seedlings under ambient and elevated CO2 and under low and high N availability. Most plant and fungal parameters were significantly affected by fungal species, CO2 leveI and N supply. Under N limitation and at elevated CO2, a large part of photoassimilates were rapidly wasted in respiration through a mycorrhizal overflow CO2 tapo Increasing N availability potentially relieved mycorrhiza-induced PNL under elevated CO2. I also investigated the effects of different Dark Septate root Endophytic fungi (DSE) on growth and nutrient status of Scots pine seedlings because nothing was known about the direction and magnitude of their effects under conditions of N-limitation and elevated CO2. None of the DSE fungi caused mortality in the host. Under elevated CO2 plant biomass increased on average by 17% when inoculated with DSE. Shoot N concentration decreased by 57% under elevated CO2. Even though under elevated C02 and low N availability the length of extraradical hyphae increased by 53% and no evidence was found for significant N competition with the host. I conclude that the impact of DSE is more through improved nutrient use efficiency by the plant than through enhanced nutrient acquisition. Possibly, DSE react differently to global change than ECM fungi, indicating that there are limits to the degree of similarity in mutualistic function between both groups. In conc1usion, only under conditions where the amount of extraradical mycelium is sub-optimal from the perspective of plant nutrition, will increased mycelial biomass, induced by elevated CO2, be profitable for the plant. If, however, the amount of extraradical mycelium is already supra-optimal from a phytocentric perspective, further increases in C allocation to the fungus will increase fungar fitness but will not be profitable to the plant. Increased fungal fitness could then enhance PNL. The diversity among fungal species and their individual responses to CO2 and nutrient availability will therefore have a major impact on plant performance. My findings have therefore confirmed the need to conceptually separate mycocentric and phytocentric views.
650 $aDióxido de Carbono
650 $aFungo
650 $aMicorriza
650 $aMicrorganismo
650 $aNitrogênio
650 $aPinheiro
650 $aSolo
653 $aPinus silvestris
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| 7. |  | LAURA, V. A.; CARDOSO, A. I. I.; CUNHA-LAURA, A. L.; FAVERO, S. Germinação 'in vitro' de grãos de pólen de flores de aboboreira 'Piramoita' conservadas sob diferentes formas. Horticultura Brasileira, Brasília, v. 22, n. 2, jul. 2004. Suplemento 2. Título em inglês: 'In vitro' pollen germination from staminate flowers of summer squash 'piramoita' stored under different forms. Edição do Congresso Brasileiro de Olericultura, 44., 2004, Campo Grande, MS.| Biblioteca(s): Embrapa Gado de Corte. |
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| 10. | | SALATA, A. da C.; GODOY, A. R.; KANO, C.; HIGUTI, A. R. O.; CARDOSO, A. I. I.; EVANGELISTA, R. M. Produção e qualidade de frutos de ervilha torta submetidas a diferentes níveis de adubação potássica. Nucleus, Ituverava, v. 8, n. 2, p. 127-134, out. 2011.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: B - 5 |
| Biblioteca(s): Embrapa Amazônia Ocidental. |
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| 11. | | GODOY, A. R.; SALATA, A. C.; CARDOSO, A. I. I.; EVANGELISTA, R. M.; KANO, C.; HIGUTI, A. R. O. Produção e qualidade pós-colheita de couve-flor em função de doses de potássio em cobertura. Scientia Agraria Paranaensis, v. 11, n. 2, p. 33-42, 2012.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: B - 5 |
| Biblioteca(s): Embrapa Amazônia Ocidental. |
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| Registros recuperados : 12 | |
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