Iron stress induces primary and secondary micronutrient stresses in high yielding tropical rice

Abstract

Two indica rice (Oryza sativa L.) cultivars, viz. ‘Swarna’ and ‘Kalinga III’ were compared for their response to iron (Fe) stress. The cultivars were raised with four Fe levels viz. 0.05, 1, 5, 10 mg L−1 in hydroponic culture. Plant growth, soluble protein, chlorophyll content and phytoferritin of leaves increased significantly with increase in Fe concentration up to 5 mg L−1, but decreased at 10 mg L−1. In contrast, lipid peroxidation, decreased up to 5 mg L−1 then increased at 10 mg L−1. However, at 10 mg L−1 of Fe these parameters were more adversely affected in ‘Swarna’ than ‘Kalinga III’. The later also accumulated relatively more Fe, zinc (Zn), manganese (Mn), and copper (Cu) from the growing medium. Zinc concentrations of the tissue, on the other hand, exhibited the opposite trend. Iron stress may, thus lead to secondary metallic ion stresses and under such situations cultivars like ‘Kalinga III’ will perform better than ‘Swarna’.