Study On Accumulation Characteristics And Tolerance Of Lobelia Sequinii Lévl. Et Vant To Lead

Phytoremediation technology is the focus of domestic and international environmental improvement and front field in recent years,it's a technology to reduce heavy metal content in soil which utilizes some patience or hyperaccumulator plants to ultra absorb the heavy metal from soil.By our laboratory's survey on plant vegetation in mine area of Chipugou in Ganluo County,Liangshan State,Sichuan Province,it was found that Lobelia sequinii Levl.et Vant distributed broadly in this area,the biomass is big,Pb content was high,and it had greatly tolerance to the Pb pollution.Therefore,Lobelia sequinii was cultivated in soil pot.The study on this plant's tolerance to lead could provide the basis for phytoremediation technology,and it had great significance.The main contents of this study were,the effects of lead on the growth,physiological and biochemical characteristics in adverse circumstance of Lobelia sequinii,lead content in different positions of the plant,the variety forms of soil lead content after the pot cultivation,the correlation analysis on the relationship between these characteristics and lead treatments on Lobelia sequinii.The results were as follows:(1)Lobelia sequinii's weight,height,root length and root weight had the same change regulation.The all decreased at first,under the 1000mg/kg lead treatment they all increased,then decreased.With the density of lead treatments becoming higher the florescence of Lobelia sequinii became earlier.(2)The lead content of underground and above ground positions of Lobelia sequinii increased with the increasing of lead treatments.Under the 4000mg/kg lead treatment,lead content in every positions of plant was the higtest:lead content in root was 5401.56mg/kg;lead content in shoot was 243.65mg/kg;lead content in leaf was 837.68mg/kg;lead content in sead was 79.82mg/kg;above ground parts content of lead was 338.65mg/kg.The largest absorption rate(the percentage of the lead content in plant by lead content in soil)was in the root,Generally,the lead content in above ground parts was low. There was no obvious rule between different positions absorption rate and the density of lead treatments.Between 300mg/kg and 1000mg/kg lead treatment,the absorption rate was root＞shoots＞leaf＞sead;When the density of lead treatments were 3000 mg/kg and 4000 mg/kg,the absorption rate was root＞leaf＞shoots＞sead.The TF of Lobelia sequinii for lead is＜1,the most lead is accumulated in root was found.When the density of lead treatment was 1000 mg/kg,the TMT was highest—2.378mg/plant.The total accumulation of plant was large,When the density of lead treatments was 1000 mg/kg,the total accumulation of plant was highest:9.956mg/plant.Lobelia sequinii didn't have the characteristics of Phytoremediater,but Lobelia sequinii could accumulate considerable lead content by its biomass,it had great tolerance to lead,and could be considered a material of Phytoremediation technology of lead pollution.(3)Lead treatments effected the antioxidant system in adverse circumstance of Lobelia sequinii,POD,SOD and CAT increased with the increasing of lead treatments in generally, they all increased at first then decreased.With the increasing of lead treatments,MDA content increased.The chlorophyll content under lead treatments was higher than CK.With the increasing of lead treatments Chla,Chlb,total Chl content had generally tendency,under the low lead treatments,the chlorophyll content increased at first then decreased.Under the high lead treatments,the chlorophyll content increased.(4)After soil pot cultivation,the accumulation of Lobelia sequinii changed the lead forms content in soil,the content of lead forms was variable with lead treatments.The total lead,the content of variety forms lead were proportional to different positions accumulation of lead in Lobelia sequinii.