| The potential harm of soil lead pollution to ecological environment and human health has been Increasingly and widely concerned.Pytoremediation,as a kind of new and effective technology,has become an important method for cleanup lead in contaminated sites Current documented lead hyperaccumulators were not widely used because of their low biomass region-specific characters,or environment dependence.Thus,screening lead hyperaccumulators that suits local ecological environment conditions has the research focus.Buddleja officinalis Maxim is widely distributed in Yunnan,its rapid growth and large biomass can severed as a candidate for lead hyperaccumulators for phytoremediation.This paper based on pot experiment,observing the character of absorb for lead,and examining the effect of nutrient elements(N,P,K)on the lead uptake,ecophysiological response of the hyperaccumulators,include chlorophyll content and soluble sugar content, the plant length and biomass.The major results are as follows:Buddleja officinalis Maxim can grow in lead polluted soil;which had tolerant to lead, and had excellent absorb ability to lead:the concentration of lead in plants increases linearly with the increase of lead concentration in soil.the maximum content of lead in leaf of plant was 471mg·kg-1,525mg·kg-1in stem,root was 617mg·kg-1,distribut rule of lead in plant is root＞stem＞leaf,Concentration of mirgration in plant was3.82mg/individual, which attaint the maxmum concentration when the disposal concentration is 1400mg·kg-1, as the time the uptaking ability grow.Fetilization of nitrogen,phosphorus,potassium,and can enhance Phyoremediation efficiency of Buddleja officinalis Maxim in lead contaminated soil.The concentration of lead in plant were different in plant parts,with increasing nitrogen supply level and the value reached maximum were 420mg·kg-1in leaf,408mg·kg-1in stem,600mg·kg-1in shoot,the maximum observed at P treatment of 0.06mg·kg-1,the accumulation of lead were decline at last.The change trend of lead content on the potassium fertilizer is same to P,the fluctuate range increased more narrow with the K fertilizer than the P fertilizer.The drops of pH value result in the rise of the lead concentration,which decline at the mixmum pH value relativly.Physiological change include:Chlorophyll content fall with the increase of lead concentration,indicate that the Pb has inhibited effect on the photosynthesis,in soluble sugar content respects,the value is decline,the phenomenon illustrate that metabolism of plant was disturbed by lead,the change of chlorophyll is cros to the lead concentration of plant in the case of add N,P and K fertilize to soil.Soluble sugar content changes with the emergence of a minimum in the case of N,K fertilizer added,soluble sugar content arise subsequently.With the P fertilizer added soluble Sugar changed slowly.have an effect on the metabolism of plants.The change of plant height and biomass is two intuitionistic inspections of plant's physiological and ecological effects.Poisoning effect of lead on the plants in these two facts are more obvious.Although The value was reduced compare with blank samples, content of lead absorbed by one individual rising;Impose a single fertilizer,comparing the amount of lead in plants,the data show that K fertilizer is good to repair of lead-contaminated soil,the change of pH value of soil have great impact on plant. |
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