Effect On Growth And Heavy Metal Accumulation Of Moso Bamboo (Phyllostachys Pubescens) Under Different Control Meatures

Based on Phyllostachys pubescens(moso bamboo) seedlings as experimental material and multi-metal contaminated soil as research object, pot experiment is conducted to investigate the effect on plant growth condition and the ability of absorption, transport and enrichment of heavy metals under three different assistant measures. The main conclusions are as follows:(1) Add four biochars to the soil contaminated with heavy metals, a better growth promotion has been showed to the root, stem and leaf of moso bamboo, including the biggest increase for biomass by rice straw biochar. All the biochars reduce the solubility of Cu, Zn, Cd and Pb in the soils. At the same time significantly reduce the heavy metal content in plants with the maximum reduction of 77% Cd. In this experiment, add 5% rice straw biochar have the best effect in four biochars in the promotion of plant growth and decrease of heavy metal content in the plants. Therefore, a proper addition of biochars to the soil will be helpful to the heavy metal removal in the light levels pollution of the soil.(2)Comparison of synthetic chelators and low molecular weight organic acids in enhancing phytoextraction of heavy metals, the results are as follows: both EDTA and citric acid reduce the growth of roots and shoots of moso bamboo, but it has no significant growth inhibit in the plant. When add in middle and high level of EDTA can greatly promote the Cu absorption of roots and shoots of moso bamboo. It reach the maximum of 271.5 和 18.6mg?kg-1 Cu under 10 mmol·kg-1of EDTA and increase56%和 85% of Cu and 52%与 211% of Pb compared to the control, respectively. Synthetic chelators have the better activate to heavy metals than organic acids. In conclusion, synthetic chelators have showed more effective to enhance heavy metal removal in phytoremediation and also did not cause significant toxicity to plants.(3)Through the low, medium and high concentration of IAA, GA3, 6-BA applied to soil contaminated with heavy metals, the result shows: three kinds of plant growth regulators can increase the growth of roots and shoots of moso bamboo in some extent. IAA, GA3, 6-BA were increased by2.4%~2.4%, 10.0~57.3% and 0.6%~73.0% of shoots of plants, respectively. For the heavy metal absorption of moso bamboo, three plant growth regulators did not significantly increase the Cu, Cd, Pb content in the plants. From the numerical of view, three plant growth regulators have no significant effect in the accumulation of heavy metals, but increase the biomass of moso bamboo. Therefore, it issuggested that the collaboration of plant growth regulators and synthetic chelators may together to promote the absorption, transport and accumulation of heavy metals of moso bamboo and significantly increase the phyremediation efficiency in the future studies.