Effects of Zinc and Chromium Stresses on Heavy Metal Accumulation of Rice Roots at Different Growth Stages of Rice Plants

Pot experiments were conducted to reveal the discipline of the heavy metal accumulation of rice (Oryza sativa L.) roots at different growth stages of rice plants under zinc and chromium stresses, and provided the basis for safe production of rice grains. The results showed as follows: with increasing concentration of zinc in soil, the zinc content in rice roots increased at first and then decreased at different growth stages of rice plants. With increasing concentration of chromium in soil, the chromium content in rice roots increased at different stages of rice plants. The order of zinc content in rice roots was: tillering stage > filling stage > booting stage, and the order of chromium content was: booting stage > filling stage > tillering stage. Partial correlation analysis showed that: the correlation was achieved at a significant or very significant level between the zinc content in rice roots and zinc concentration in soil at different growth stages, and the correlation was achieved at a significant level about the chromium. The concentration of zinc and chromium in soil did not have compound effects to zinc content or chromium content in rice roots.