Registro Completo |
Biblioteca(s): |
Embrapa Semiárido; Embrapa Soja. |
Data corrente: |
06/07/1994 |
Data da última atualização: |
01/08/2020 |
Autoria: |
WANG, S. R. |
Título: |
Effect of nitrogen and other factors on plant growth responses to vesicular-arbuscular mycorrhiza. |
Ano de publicação: |
1984 |
Fonte/Imprenta: |
London: University of London, 1984. |
Páginas: |
236 f. |
Idioma: |
Inglês |
Notas: |
Ph.D. Thesis. |
Conteúdo: |
High concentrations of phosphate in plants have been found to decrease vesicular-arbuscular (VA) mycorrhizal infection and its effect on plant growth, However, little is known about the effect of nitrogen on the VA mycorrhizal symbiosis, and this was examined in the present study. Mycorrhizal infection in onion was inhibited by nitrogen not only when N was added to soil, but also when were dipped into a solution containing N. Per cent N in the root tissues was increased in both cases. By contrast, infection and nitrogen concentrations in white clover were little a affected by added nitrogen. The level of nitrogen in the plant rather than in the soil was believed to be the major factor affecting infection. Similar results were obtained with other legume-non-legume combinations. In other tests with legumes, nodulation was stimulated by the VA fungus. The forms of nitrogen are important to mycorrhizal plants and their effects are influenced by soil phosphate levels. In experiments with onions growing in a soil in which they both N and P deficient, plants only responded to added nitrogen when phosphate was also applied. Non-mycorrhizal plants given phosphate grew well with both Ca(NO3)2.4H2O and NH4NO3. Mycorrhizal plants grew bigger with nitrogen added as Ca(NO3)2.4H2O than as NH4NO3; when a small amount of P was applied, mycorrhizal plants grew equally well with either form of N. It was inferred that mycorrhiza is inhibited more by ammonium-nitrogen than by nitrate-nitrogen. Shading decreased mycorrhizal infection, an effect that was more pronounced with ammonium-N ((NH4)2SO4) than with nitrate-N (Ca(NO3)2.4H2O). Onion roots contained less carbohydrate in the ammonium-N than in the nitrate-N treatment and the differences were greater in shaded plants. These results showed a direct relationship between root carbohydrate levels and early VA mycorrhizal infection in young onion seedlings, thereby supporting the "Carbohydrate theory" of Bjorkman for ectomycorrhiza. MenosHigh concentrations of phosphate in plants have been found to decrease vesicular-arbuscular (VA) mycorrhizal infection and its effect on plant growth, However, little is known about the effect of nitrogen on the VA mycorrhizal symbiosis, and this was examined in the present study. Mycorrhizal infection in onion was inhibited by nitrogen not only when N was added to soil, but also when were dipped into a solution containing N. Per cent N in the root tissues was increased in both cases. By contrast, infection and nitrogen concentrations in white clover were little a affected by added nitrogen. The level of nitrogen in the plant rather than in the soil was believed to be the major factor affecting infection. Similar results were obtained with other legume-non-legume combinations. In other tests with legumes, nodulation was stimulated by the VA fungus. The forms of nitrogen are important to mycorrhizal plants and their effects are influenced by soil phosphate levels. In experiments with onions growing in a soil in which they both N and P deficient, plants only responded to added nitrogen when phosphate was also applied. Non-mycorrhizal plants given phosphate grew well with both Ca(NO3)2.4H2O and NH4NO3. Mycorrhizal plants grew bigger with nitrogen added as Ca(NO3)2.4H2O than as NH4NO3; when a small amount of P was applied, mycorrhizal plants grew equally well with either form of N. It was inferred that mycorrhiza is inhibited more by ammonium-nitrogen than by nitrate-nitrogen. S... Mostrar Tudo |
Palavras-Chave: |
Crescimento de planta; Efeito; Fungus; Growth; Inglaterra; Mycorrhiza; Phosphatos; Plant; VA; Vesicular-arbuscular. |
Thesagro: |
Carboidrato; Crescimento; Fosfato; Fungo; Micorriza; Nitrogênio; Planta; Simbiose. |
Thesaurus Nal: |
England; nitrogen; plant growth; symbiosis. |
Categoria do assunto: |
-- X Pesquisa, Tecnologia e Engenharia |
Marc: |
LEADER 02953nam a2200397 a 4500 001 1444507 005 2020-08-01 008 1984 bl uuuu m 00u1 u #d 100 1 $aWANG, S. R. 245 $aEffect of nitrogen and other factors on plant growth responses to vesicular-arbuscular mycorrhiza. 260 $aLondon: University of London$c1984 300 $a236 f. 500 $aPh.D. Thesis. 520 $aHigh concentrations of phosphate in plants have been found to decrease vesicular-arbuscular (VA) mycorrhizal infection and its effect on plant growth, However, little is known about the effect of nitrogen on the VA mycorrhizal symbiosis, and this was examined in the present study. Mycorrhizal infection in onion was inhibited by nitrogen not only when N was added to soil, but also when were dipped into a solution containing N. Per cent N in the root tissues was increased in both cases. By contrast, infection and nitrogen concentrations in white clover were little a affected by added nitrogen. The level of nitrogen in the plant rather than in the soil was believed to be the major factor affecting infection. Similar results were obtained with other legume-non-legume combinations. In other tests with legumes, nodulation was stimulated by the VA fungus. The forms of nitrogen are important to mycorrhizal plants and their effects are influenced by soil phosphate levels. In experiments with onions growing in a soil in which they both N and P deficient, plants only responded to added nitrogen when phosphate was also applied. Non-mycorrhizal plants given phosphate grew well with both Ca(NO3)2.4H2O and NH4NO3. Mycorrhizal plants grew bigger with nitrogen added as Ca(NO3)2.4H2O than as NH4NO3; when a small amount of P was applied, mycorrhizal plants grew equally well with either form of N. It was inferred that mycorrhiza is inhibited more by ammonium-nitrogen than by nitrate-nitrogen. Shading decreased mycorrhizal infection, an effect that was more pronounced with ammonium-N ((NH4)2SO4) than with nitrate-N (Ca(NO3)2.4H2O). Onion roots contained less carbohydrate in the ammonium-N than in the nitrate-N treatment and the differences were greater in shaded plants. These results showed a direct relationship between root carbohydrate levels and early VA mycorrhizal infection in young onion seedlings, thereby supporting the "Carbohydrate theory" of Bjorkman for ectomycorrhiza. 650 $aEngland 650 $anitrogen 650 $aplant growth 650 $asymbiosis 650 $aCarboidrato 650 $aCrescimento 650 $aFosfato 650 $aFungo 650 $aMicorriza 650 $aNitrogênio 650 $aPlanta 650 $aSimbiose 653 $aCrescimento de planta 653 $aEfeito 653 $aFungus 653 $aGrowth 653 $aInglaterra 653 $aMycorrhiza 653 $aPhosphatos 653 $aPlant 653 $aVA 653 $aVesicular-arbuscular
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Embrapa Soja (CNPSO) |
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