Effects of Mercury and Cadmium Pollution on Rice Growth and Development

Mercury(Hg) and cadmium(Cd) are pollutants in farmland soils.Their pollution has grown with the development of industry,which has threatened human health and agricultural production.Current study took rice as the object,the influence of different Hg and Cd concentrations on the rice growth,as well as the transport and the accumulation of metals in rice were studied by water culture experiment.The results showed that,the absorption amount of Hg and Cd in rice increased with the increasing Hg and Cd application rate.In different growth period of rice,positive correlation was found between Hg and Cd concentrations in nutrient solution and their contents in root,stem and leaf of rice.The inhibition of Hg and Cd to rice strengthened with the increasing Hg and Cd concentrations.Therefore,the absorption ability of rice to Hg and Cd decreased,especially for the rice species with shorter growth duration.The correlation analysis showed that,under the current experiment condition,the influence of Hg and Cd on rice increased with the increasing Hg and Cd rate,and for the rice with shorter growth duration,the influence was bigger.Based on the results of Hg and Cd in root and stem of rice and their concentrations in nutrient solution,it can be concluded as follows:The accumulation of Hg and Cd in root and stem of rice increased with the increasing Hg and Cd application amount,however,when the accumulation reached to a certain level,the increasing amplitude decreased,and the accumulation of Hg in nutrient solution was greater than that in root and stem of rice.