Copper-molybdenum interaction in maize

Abstract

Maize (Zea mays l.) cv. Ganga 2 was grown in refined sand at deficient (0.0001 µm), normal (0.2 µ_M), and excess (200µ_M) levels of molybdenum each at three levels of copper, deficient (0.01 µ_M), normal (1 µ_M), and excess (50 µ_M).

The molybdenum deficiency effects at normal copper—reduction in dry weight, leaf molybdenum, chlorophyll, protein nitrogen, nitrate reductase activity, and increase in peroxidase—were accentuated by excess copper. The changes in maize induced by the deficiency of copper at normal molybdenum level, decrease of dry weight, of content of chlorophyll, leaf copper, and protein nitrogen, and of activities of cytochrome oxidase and nitrate reductase became more pronounced when molybdenum was also deficient.

The depression in the dry weight, protein nitrogen content, and acid phosphatase activity and stimulation of the activities of catalase, peroxidase, and ribonuclease were more pronounced under the combined toxic effect of both copper and molybdenum than under the single toxic effect of either copper or molybdenum.

Interaction was observed between normal Cu-deficient Mo and excess Cu-deficient Mo levels; deficient Cu-normal Mo and deficient Cu-deficient Mo levels; excess Cu-excess Mo and excess Cu-normal Mo levels and between excess Cu-excess Mo and normal Cu-excess Mo levels.

Key Words:

• Cu-Mo interaction
• enzymes
• N fractions
• Zea mays