Interactive studies of potassium and copper with cadmium on seed germination and early seedling growth in maize (Zea mays L.).

In the present study a novel approach has been made to evaluate the toxicity of cadmium in maize (Zea mays L. cv KJ9451) in terms of germination, seedling growth, pigment development and relevant enzyme activity and the possible remedial approach using potassium and copper to reduce cadmium toxicity. For the present investigations maize seeds were sown in petridishes on filter paper in triplicate containing different doses of cadmium viz. 0.05, 0. 10, 0.25, 0.50, 0.75 and 1.0 mM and for interactive studies maize seeds sown in 0.50, 0.75 and 1.00 mM Cd concentration were subjected to 0.50 and 1.00 mM concentration of potassium and copper respectively. At the high cadmium concentrations, germination percentage was decreased. I also showed considerable reduction in plumule length, radicle length and number of lateral roots while the potassium and copper combination with cadmium increased the seedling growth. The calculated values of SVI were found to be decreased with increase in the concentration of cadmium. Decreased GRI values were observed in maize treated with three higher concentrations of cadmium but the combination of potassium and copper showed recovery in GRI values. The fresh weight, dry weight and moisture contents were also found reduced with higher cadmium concentrations but the potassium and copper combination showed recovery when used with higher concentration of cadmium. Declined chlorophyll contents were noticed under the influence of higher cadmium concentrations. Both the combination of potassium and copper used with 0.50, 0.75 and 1.00 mM cadmium concentrations resulted in increased chlorophyll and pheophytin contents and decreased in Cu combination respectively. The potassium and copper (both 0.50 and 1.00 mM) with 0.75 and 1.00 mM cadmium increased the carotenoid contents although lone cadmium decreased it. Amylase activity was found to be gradually reduced at all concentrations of cadmium. The 0.50 mM and 1.00mM potassium combination improved amylase activity. Marked increase in catalase and peroxidase activity by the application of test chemical was observed in different doses of cadmium. The potassium and copper combination used with cadmium concentration reduced catalase activity while peroxidase activity was promoted.