Avaliacao do pH da rizosfera de genótipos de café em resposta a toxidez de alumínio no solo

This work was carried out in greenhouse aiming to evaluate the relationship between rhizosphere-pH and aluminum tolerance of five coffee genotypes, grown with or without soil liming. Coffee plants were grown in plastic boxes, with roots developing near the cover. After 90 days the lids were removed and a solid agar layer with pH indicator was placed on the surface of soil and roots. It was also evaluated roots and shoots dry biomass production and roots length and surface. When the soil was limed, it was observed the development of yellow color near the roots indicating pH decrease. This result was confirmed by observing soil and rhizosphere-pH changes, varying between 0.2 and 0.3 units of pH. On the other hand, in the presence of Al it was not observed differences among soil and rhizosphere-pH, indicating that the change of pH induced by roots is not the mechanism of Al tolerance in coffee plants, since sensible and tolerant genotypes showed the same behavior

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Bibliographic Details
Main Authors: 50632 Braccini, M. do C.L., 91260 Martínez, H.E.P., 50633 Braccini, A. de L.E., 93403 Mendonca, S.M. de
Format: biblioteca
Published: 2000
Subjects:COFFEA ARABICA, GENOTIPOS, RIZOSFERA, PH, ALUMINIO, FITOTOXICIDAD, TOLERANCIA,
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Summary:This work was carried out in greenhouse aiming to evaluate the relationship between rhizosphere-pH and aluminum tolerance of five coffee genotypes, grown with or without soil liming. Coffee plants were grown in plastic boxes, with roots developing near the cover. After 90 days the lids were removed and a solid agar layer with pH indicator was placed on the surface of soil and roots. It was also evaluated roots and shoots dry biomass production and roots length and surface. When the soil was limed, it was observed the development of yellow color near the roots indicating pH decrease. This result was confirmed by observing soil and rhizosphere-pH changes, varying between 0.2 and 0.3 units of pH. On the other hand, in the presence of Al it was not observed differences among soil and rhizosphere-pH, indicating that the change of pH induced by roots is not the mechanism of Al tolerance in coffee plants, since sensible and tolerant genotypes showed the same behavior