Data/hora: 03/06/2024 14:53:52

Biblioteca(s): | Embrapa Unidades Centrais.
Data corrente: | 15/07/1998
Data da última atualização: | 15/07/1998
Autoria: | SIQUEIRA, J. O.; HUBBEL, D. H.; VALLE, R. R.
Título: | Effects of phosphorus on formation of the vesicular-arbuscular mycorrhizal symbiosis.
Ano de publicação: | 1984
Fonte/Imprenta: | Pesquisa Agropecuaria Brasileira, Brasilia, v.19, n.12, p. 1465-1474. dez. 1984.
Idioma: | Inglês
Conteúdo: | The effect of phosphorus (P) on formation of the vesicular-arbuscular mycorrhizal (VAM) symbiosis was examined. Using a sand-hydroponic culture chamber, increasing P levels were supplied to soybean (Glycine max L. Merril) seedlings. It was found that indirect supply of P up to 600 mM did not affect the germination of Glomus mosseae chlamydospores in the rhizosphere. Similar results were found for germination of either G. mosseae or Gigaspora margarita spores in the rhizosphere of soybean growing in soil amended with increasing P levels. These data suggest that P controls VAM formation at some stage after spore germination in the rhizosphere has occurred. Increasing P supply to the soil enhanced carbon exchange rate, sugar content of the roots and decreased sugars in the root exudates. Bioassays using root extracts from plants supplied with different P levels showed differential effects on germination of G. mosseae and G. margarita spores in vitro. Extracts from plants well supplied with P had high levels of sugars and inhibited spore germination. It was proposed that P controls root colonization through its effect on host carbon metabolism. In addition, the relationship between P availability and plant growth response to mycorrhizal formation is discussed.
Palavras-Chave: | Formacao de micorrizas; Fungos endomicorrizicos; Germinacao de esporos; Mycorrhizal formation; VAM fungi.
Thesaurus Nal: | spore germination.
Categoria do assunto: | --
Registro original: | Embrapa Unidades Centrais (AI-SEDE)
Exemplares: | AI-SEDE - (20023-1) - UMT - AP - -- - 630.72081 - P474 - 63072081 - DIS