Excess copper and manganese alters the growth and vigour of maize seedlings in solution culture

To elucidate the detrimental effect of excess Cu and excess Mn in maize (Zea mays, L) cv. Ganga2, seeds were germinated in petri-dishes under controlled conditions and supplied distilled water and nutrient solution at varying doses of Cu and Mn. Compared to the maize seedlings grown in complete nutrient solution, excess supply of Cu decreased the growth of shoot and root drastically whereas excess Mn was found to promote the growth of shoot and root significantly. The tissue concentration of Cu and Mn increased with increasing level of Cu and Mn. The concentration of iron decreased in shoots and increased in roots significantly with increasing supply of Cu and Mn. The activity of catalase- an iron containing enzyme, decreased at excess Cu and increased at excess Mn suggesting interference of excess nutrients in iron metabolism of plants. Decreased activity of amylase and proteinase in seeds was also observed at excess Cu and Mn.