Influence of iron stress on ion absorption, metabolism and growth of rice (Oryza sativa L.) plants in nutrient solution

摘要

Three rice (Oryza sativa L.) genotypes viz. CR 683, Budumoni and Akisali were grown in sand culture in a green house with three levels of iron in nutrient solutions viz., 0.045 mM Fe (control), 5.34 and 7.12 mM Fe. Bronzing score was higher in the seedlings grown at 7.12 mM iron in the medium. Occurrence of bronzing was severe in the variety CR683 and Akisali. Shoot length, root and shoot dry weight were affected by higher levels of Fe in the growth medium. Variety Budumoni maintained higher leaf chlorophyll content, nitrate reductase activity and total soluble protein in the leaves at 5.34 and 7.12 mM Fe. Higher concentration of iron in the nutrient solution exerted an inhibiting effect on the concentrations of almost all the macro and micro nutrients in the root and shoot. Higher Fe and N concentrations and lower P, K, Mn, Cu, Zn concentrations in root and shoot were recorded in plants grown in medium with 7.12 mM Fe. Variety Budumoni perforated relatively better in comparison to other tested varieties at higher iron level.