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Low-P tolerance by maize (Zea mays L.) genotypes: Significance of root growth, and organic acids and acid phosphatase root exudation

Gaume, Alain ; Mächler, Felix ; De León, Carlos ; Narro, Luis ; Frossard, Emmanuel

In: Plant and Soil, 2001, vol. 228, no. 2, p. 253-264

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    Titre
    • Low-P tolerance by maize (Zea mays L.) genotypes: Significance of root growth, and organic acids and acid phosphatase root exudation
    Auteur
    • Gaume, Alain. Institute of Plant Sciences, Swiss Federal Institute of Technology (ETH Zurich), Eschikon 33, Postfach 185, CH-8315, Lindau, Switzerland
    • Mächler, Felix. Institute of Plant Sciences, Swiss Federal Institute of Technology (ETH Zurich), Eschikon 33, Postfach 185, CH-8315, Lindau, Switzerland
    • De León, Carlos. CIMMYT regional office at CIAT, A. A. 6713, Cali, Colombia
    • Narro, Luis. CIMMYT regional office at CIAT, A. A. 6713, Cali, Colombia
    • Frossard, Emmanuel. Institute of Plant Sciences, Swiss Federal Institute of Technology (ETH Zurich), Eschikon 33, Postfach 185, CH-8315, Lindau, Switzerland
    Type de document
    • Postprint
    Langue
    • Anglais
    Publié dans
    • Plant and Soil, 2001, vol. 228, no. 2, p. 253-264. Kluwer Academic Publishers
    Autre version électronique
    Identifiant OAI-PMH
    • oai:doc.rero.ch:321844
    Summary
    We investigated some mechanisms, which allow maize genotypes to adapt to soils which are low in available P. Dry matter production, root/shoot-ratio, root length and root exudation of organic acids and acid phosphatase were investigated in four maize genotypes grown under P-deficient and P-sufficient conditions in sterile hydroponic culture. A low-P tolerant, an acid-tolerant and a low-P susceptible genotype of maize were compared with a Swiss commercial cultivar. The study found increased root development and increased exudation of acid phosphatase under P-deficient conditions in all maize genotypes, except for the Swiss cultivar. Effects on root formation and acid phosphatase were greater for the low-P tolerant than for the low-P susceptible, and the acid soil tolerant genotypes. Organic acid contents in root tissues were increased under P deficiency and related to increased PEPC activity. However, the increase in contents was associated with an increase in exudation for the low-P tolerant genotype only. The low-P susceptible genotype was characterized by high organic acid content in roots and low organic acid exudation. The organic acids content in the phloem exudates of shoots was related to root exudation under different P supply, to the difference between lines in organic acids root content, but not to the low-P tolerance or susceptibility of maize genotypes