Regulation Of The Amount And The Time Of Silicon Application On The Cadmiun Accumulation And Translocation In The Rice (Oryza Sativa. L) Grown Under The Cadmium-polluted Soil

Cadmium is one kind of toxic elements,it is not only harmful to plant, but also threaten human health through food.Rice(Oryza sativa L),as China's important crop,plays an irreplaceable role in agricultural production, and the quality of rice is directly related to the national economy level and the human body health.Silicon is one kind of environmentally friendly additives.it canalleviate heavy metal cadmium poisoning on the rice,but most of the present studies about this are focused onthe rice seedlings horizons,not, littleon rice maturity.The aim of these research is to explore the Regulation of Silicon Application on the growthdevelopment,production and the Cadmiun Accumulation and Translocation in the Rice(Oryza Sativa. L) Grown Under the Concentration Cadmium-polluted Soil.The main results of these research as follows:1) Effects of the different concentration of silicon add on rice were observed. silicon can alleviate the poisoning of cadmium pollution, promote rice growth,andincrease the rice production.The plant height,,the per panicle rice and the seed setting rate increased after silicon application and there is have a significant increase when add 2mmol/kg silicon.Also there is a increase tendency,on the dry matter of different organs?the effective panicles and the grain weight.2) Silicon can adjust the content and cumulant of cadmium in vegetative organs of rice depend on the cadmium content of soils,the amount of silicon, the rice organsand the rice varieties. After silicon application,the cadmium enrichment coefficient and transfer coefficient of each organ are declined., part of the treatment showed significantly reduced.3) Each period to add silicon can significantly increased rice spike rate, seed rate,up respectively 89.8%?88.2%.And there is an increase tendency on the effective panicles and the grain weight. It indicate that different periods to add silicon can reduce the toxic cadmium on rice,and promote the growth and the production of rice.4) The different periods to add silicon have some differences on the Cadmium in rice plants. All periods to add silicon can increase the contentration and accumulation of cadmium in rice root, and reduce the content and accumulation of cadmium in the above-groundorgan,also it can reduce t the cadmium enrichment coefficient and transfer coefficient in each rice organs,to make the majority of cadmium retention in the roots. the elongation stage in rice to add silicon is the best, the concentration of cadmium in white rice were only 0.534mg/kg, the enrichment factor and transfer coefficient of cadmium were only 0.012,0.00315) After silicon application, the soil p H value is increased significantly and the cadmium activity is reduced greatly,make decreased the concentration of available Cd significantly.The correlation coefficient of soil p H value witht he concentration of available Cd.Then after add silicon, the concentration of Cd in stem bleeding sap decreased 42.96%,the concentration of Cd in phloem flow was significantly reduced, indicating that silicon can be suppressed cadmium plexus roots shift to rice shoot, so that cadmium retention in the roots, reducing the accumulation of cadmium on other organs.