MANGANESE AND ZINC CONCENTRATIONS IN MAIZE GENOTYPES GROWN ON SOILS DIFFERING IN ACIDITY

摘要

Drought and soil acidity are two major abiotic stress factors limiting maize production worldwide, generating imbalances in the manganese (Mn) and zinc (Zn) status in plants. This study was conducted to determine the effects of drought stress on the Mn and Zn status in maize genotypes grown on acid and non-acid soils and how the Mn and Zn status affects the changes in grain yield caused by drought stress and soil acidity. Seventeen genotypes were grown at two locations differing in soil acidity in Eastern Croatia in 2003 and 2004. Positive values of an aridity index indicated drought stress in 2003. The genotypes had much higher Mn and Zn concentrations on acid soil than on non-acid soil: more than twice as high in both seasons for Zn and about 6 and 9 times higher in normal and in dry seasons, respectively, for Mn. This demonstrates that drought combined with soil acidity led to the excessive accumulation of Mn in maize plants. However, variation was observed between the maize genotypes for the Mnaccumulation on soils differing in acidity when drought occurred. Some genotypes accumulated Mn on acid soil irrespective of drought. The Mn and Zn status had no discernible effect on the changes in grain yield caused by drought stress and/or soil acidity.