COPPER–MANGANESE INTERACTION IN CAULIFLOWER

ABSTRACT

Cauliflower (Brassica oleracea L. var. Botrytis) cv. Maghi was grown in refined sand supplied with complete nutrient solution with normal copper (Cu) and manganese (Mn) (1 ÂμM Cu; 10 ÂμM Mn) and in solutions deficient in either Cu (0.01 ÂμM) or Mn (0.1 ÂμM) or both Cu and Mn together to study the interactive effects of Cu and Mn. The effects of Cu deficiency at deficient Cu-normal Mn treatment, i.e., intensity of visible copper deficiency symptoms, reduced biomass, concentrations of Cu, DNA, RNA and decrease in activities of cytochrome c oxidase, acid phosphatase, and ribonuclease and increase in DNAse activity and phenol content in leaves were reversed in combined deficiency of both Cu and Mn reflecting an antagonism between Cu and Mn. Negative interaction was further observed when the effects of Mn deficiency at normal Cu-deficient Mn treatment, i.e., severity in Mn deficiency symptoms, decrease in biomass, Hill reaction, and acid phosphatase activity, concentrations of DNA, RNA, and increase in phenols and activities of cytochrome c oxidase and ascorbic acid oxidase were reversed when both Cu and Mn were in low supply together.

Acknowledgments