环境激素Pb对水稻生长发育的影响及污染修复

采用盆栽实验方法,研究环境激素Pb对水稻生长发育的影响、Pb在作物体内的积累特性及采用不同方法修复Pb污染土壤.研究结果表明,在PbCd复合污染条件下,Pb含量为300 mg/kg时,影响水稻的正常生长发育,水稻的减产幅度为13.3%.Pb在水稻不同部位的吸收表明,根系积累的Pb量占植株总积累量的98.36%,茎叶积累量占1.52%,籽实积累量仅占0.117%;复合元素PbCd投加到土壤中,导致水稻籽实中的Pb含量超过食品卫生标准,共存的Cd促进了水稻籽实对的吸收.经过石灰及石灰 CaMgP肥处理,可以降低土壤中Pb的活性;水稻根系可大量吸收土壤中的Pb,将根系从土壤中清除,即可达到污染修复的目的.

Effect and remediation of environmental hormone Pb on rice growth in polluted soil

The present paper is aimed at reporting its authors' pot grade experiments with the effect of Pb on rice plant growth and its remedial role for the Pb polluted soil. The experimental results have shown that in Pb and Cd combined treatment with Pb concentration of 300 mg/kg, the normal growth of rice plant should be affected to reduce the rice yield by 13.3%. Our experiments also suggest that the root of the rice plant is a barrier for Pb absorption by the stalk with leaves and grains. Actually, Pb content of the rice grain as a result of the Pb and Cd treatment may go beyond the generally accepted food health standard because the co-existing of Cd is likely to promote the absorption of Pb by the rice grain. In the actual Pb polluted soils, the bio-available Pb could be reduced as a result of application of lime or lime+CaMgP fertilizer. Besides, the environmental hormone Pb tends to accumulate in the rice roots, therefore, it would be better to remove rice roots from the soil so as to achieve the soil remediation. Soil remediation can also be achieved by means of biotechnical and chemical modification, which embrace the duality of a sustainable agricultural economy and a healthy environment.