Solubilização de fósforo por bactérias endofíticas

Detalhes bibliográficos
Ano de defesa: 2010
Autor(a) principal: SOUSA, Clayton Albuquerque de lattes
Orientador(a): LIRA JUNIOR, Mario de Andrade
Banca de defesa: FREIRE, Maria Betânia Galvão dos Santos, SILVA, Maria Luiza Ribeiro Bastos da, LYRA, Maria do Carmo Catanho Pereira
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal Rural de Pernambuco
Programa de Pós-Graduação: Programa de Pós-Graduação em Ciência do Solo
Departamento: Departamento de Agronomia
País: Brasil
Palavras-chave em Português:
Área do conhecimento CNPq:
Link de acesso: http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/4910
Resumo: Soil microorganisms directly affect fertility and plant yield. Among these, inorganic phosphate solubilizers enhance phosphorus availability, and may increase phosphorus fertilizers efficiency. This work aimed to select inorganic phosphorus solubilizing bacteria as potential plant growth promoters. On the first stage, previously obtained isolates, from leaves and roots of sugarcane cultivated in Pernambuco, were tested in solid culture media with different phosphorus sources. On the second stage, three of the most solubilizing isolates, three of the least solubilizing, one considered as non-solubilizer, and a reference strain of Pseudomonas fluorescens (R-243) were tested in two liquid culture media to evaluate pH change and P solubilization over time. These isolates, and absence of inoculation, were tested in Leonard jars high and low solubility phosphorus sources, using cowpea as an indicator plant. At harvest, 44 days after planting, shoot dry mass, soluble phosphorus content on the substrate and phosphorus content on the shoot, and total shoot phosphorus were evaluated. Media composition, both for solid and liquid media, affected phosphorus solubilization ability of the endophytic bacteria. As isolates considered as low solubilizers in solid media, based on a semi-quantitative evaluation, presented high solubilization potential in liquid media, based on aquantitative determination, this evaluation system may be considered as more reliable for isolate selection. This solubilization was not directly related only to pH lowering, since different strains which lowered the media pH to the same point, had different soluble phosphorus yields. Isolates UAGC 17, 19 and 65 were the strongest solubilizers in culture media, but did not show the same efficiency when inoculated in cowpea.