Mycorrhizal symbiosis and phosphorus fertilization effects on Zea mays growth and heavy metals uptake

ABSTRACT

Arbuscular mycorrhizal fungi (AMF) can promote plant growth and reduce plant uptake of heavy metals. Phosphorus (P) fertilization can affect this relationship. We investigated maize (Zea mays L.) uptake of heavy metals after soil AMF inoculation and P fertilization. Maize biomass, glomaline and chlorophyll contents and uptake of Fe, Mn, Zn, Cu, Cd and Pb have been determined in a soil inoculated with AMF (Glomus aggregatum, or Glomus intraradices) and treated with 30 or 60 µg P-K₂HPO₄ g⁻¹ soil. Consistent variations were found between the two mycorrhizal species with respect to the colonization and glomalin content. Shoot dry weight and chlorophyll content were higher with G. intraradices than with G. aggregatum inoculation. The biomass was highest with 30 µg P g⁻¹ soil. Shoot concentrations of Cd, Pb and Zn decreased with G. aggregatum inoculation, but that of Cd and Pb increased with G. intraradices inoculation. Addition of P fertilizers decreased Cd and Zn concentrations in the shoot. AMF with P fertilization greatly reduced maize content of heavy metals. The results provide that native AMF with a moderate application rate of P fertilizers can be exploited in polluted soils to minimize the heavy metals uptake and to increase maize growth.

KEYWORDS:

• arbuscular mycorrhizae
• bioremediation
• glomalin
• heavy metals
• phosphorus fertilization
• zea mays

Acknowledgments

Professor Galal Elgharably provided guidance and Science and Technology Development Fund (STDF) sponsored the study through the project 2153 “Heavy Metals Pollution and Remediation in Soils of Assiut, Egypt”.

Additional information

Funding

Science and Technology Development Fund (STDF), Cairo, Egypt.