EFFECTS OF IRON PLAQUE ON ROOTS OF RICE ON GROWTH AND METAL CONCENTRATION OF SEEDS AND PLANT-TISSUES WHEN CULTIVATED IN EXCESS COPPER

Deposition of iron (Fe) plaque on roots of rice before exposure to exc ess of copper (Cu) was found to lessen the toxic effects of Cu. In the excess of Cu, plants with Fe plaque had significantly greater dry wei ght of roots and leaves, longer leaves, and roots, and higher concentr ation of Fe in leaves than plants without plaque. In the excess of Cu, plants without Fe plaque had more leaves showing chlorosis than plant s with plaque. Iron plaque on roots appeared to be beneficial for seed formation, since plants with plaque grown without exposure to excess Cu had highest seed weight, although differences were not significant. In the excess Cu solution, plants with plaque had significantly more Fe in seeds and more Cu in roots and in the DCB (dithionite-citrate-bi carbonate) wash than plants without plaque.