Study On The Resistance Of Ornamental Plants And The Influence Factor To Mn Stress

In order to achieve the purpose of successful phytoremediation of heavy metal polluted soil,the ornamental plants of Hunan province are chosen as the test materials. The tolerant species selecting test and the accumulation test are carried out under the hydroponic and sand-planting condition,and the soil-planting test is carried out to check whether the selected tolerant plant can be able to hyper accumulate heavy metal, and studied the effects of physiological resistance to Mn stress.Also,the accumulating test induced by EDTA obtains satisfying answer.The main results were as follows:1.The selected of tolerance ornamental plantsIn the test selecting tolerance plants from ornamental plants,By comparing the seeds burgeoning coefficient of twenty kinds of ornamental plants,it is found that the tolerance of Mirabilis jalapa L.,Calendula officinalis L.,Tagetes erecta L.,Althaea rosea Cav,Impatiens Balsamina L.,Astragalussinicus L.to Mn is the best.In the following seedling growing test,by comparing the elongation of radicels,it is found that the tolerance of Mirabilis jalapa L,Calendula officinalis L.,getes erecta L.to Mn is better.So the study of soil-planting test of the three ornamental plants is carried out in order to check it accumulating capacity to Mn.2.The impact of Physiological biochemistry characteristic in three kinds of ornamental plants to Mn stressIn order to explanat the impact of physiological biochemistry characteristic in three kinds of ornamental plants to Mn stress,determination of six closes related targets: chlorophyll,MDA,proline,three kinds of Protection enzyme(SOD,POD,CAT).The test result indicated that the chlorophyll content increased first and decreased afterwards with the increasing of the concentration of Mn.The content of MDA and proline increased,but the increases speed is different by the type.The response of three defensive enzymes of was different according to the concentration of heavy metal.It presented that three defensive enzymes have strong automatic regulation ability to protect cell membrane from destroy within lower concentration scale of Environmental Quality Standard for Soil.But in higher concentration scale,the three kind of enzymes presented different verity trend.3.The impact of growth condition of three kinds of ornamental plants to Mn stressThe height of three kinds of ornamental plants is roused with the growth,but the speed is slow down.The change of the D.W.in the shoot and root is similar with the hight,but in the mturity,the D.W.of shoot and root is bellower the previous growth period,the CK is bigger.The Mn²⁺ is started inhibited the growth of irabilis jalapa L and Calendula officinalis L in the 0.6g·kg^-1,and Tagetes erecta L.is 0.4g·kg^-1Mn²⁺.This proofed that the Tagetes erecta L is sensived.4.The characteristics of three kinds of ornamental plants Mn enrichmentThe study shows that root Mn concentrate on dropped and shoot Mn concentration roused with the extension of the growth period of three kinds of ornamental plants. Root and shoot Mn concentration was higher in the Mirabilis jalapa L than the other plants of the same level,which revealed that the moving ability of Mirahilis jalapa L was greater than Tagetes erecta L and Calendula officinalis L..The sequence of the amount of Mn distribution in the three kinds of ornamental plants was that the root preceded the shoot.The amount of the plants Mn enrichment gradually rose with the extension of the growth period of the plants before maturity and,however,it dropped at maturity because of the gradual drop of the plants Mn concentration and biomass.This change is a wise choice due to its high ecological and economic efficiency.5.The characteristics of Mirabilis jalapa L.Mn enrichments in the addition of EDTAThe addition of 0.125mmol·kg^-1～2mmol·kg^-1 EDTA to Mn mine tailings contaminated soil can increase the biomass above ground of Mirabilis jalapa L. greatly.The effect is most obvious in the EDTA treatment of 1mmol·kg^-1 respectly.The obvious ground is bigger than the upside.EDTA addition can greatly enhance the ability of heavy metal accumulation of Mirabilis jalapa L..Synthesis the change of each growth targets of Mirabilis jalapa L,consideration of the heavy metal accumulation and economical and ecological benefit,the best increased density is 1mmol·kg^-1.A good economical and ecological benefit can be obtained in the removal of heavy metal from Mn mine tailings contaminated soil by using the combined technological mode of 1 mmol·kg^-1 EDTA+Mirabilis jalapa L.