Effects of interaction between manganese and cadmium on plant growth and contents of cadmium and manganese in rice.

The effects of Mn treatment on rice growth,and Cd,Mn,Fe and Zn contents and their distribution in shoots and roots under Cd stress were investigated under hydroponics.The results showed that Cd toxicity to rice plants was markedly alleviated at normal Mn level (about 0.50 mg/L) with higher plant height,root length,and contents of chlorophyll a and chlorophyll b than at low Mn level.With the rising Cd concentration in culture solution,the Cd contents in shoots and roots increased.Under the same Cd level,the Cd content increased in rice shoots,while decreased in rice roots with the increase of Mn concentration in culture solution.The contents of Fe and Zn in rice plants significantly decreased under high level treatments of Mn and Cd.Moreover,Cd accumulation mechanism in rice plants and the application value of Mn fertilizer in alleviating Cd stress were also discussed.