草坪植物—微生物联合修复钴污染土壤

发布时间：2018-07-29 17:53

【摘要】：近几年,植物-微生物联合修复重金属污染土壤,这种方法成为了一种新兴的修复方法。这种修复方法利用土壤-微生物-植物的互利共生的关系,充分发挥了重金属超富集植物修复技术和微生物修复技术的各自优势,提高土壤的修复效率,不断改进以达到彻底修复污染土壤的目的。本研究在土壤高浓度Co2+胁迫条件下对32种草坪植物进行筛选,筛选出具有相对优良生长性状和钴抗性的4种草坪植物,利用高级生物统计学方法对其钴耐受能力进行了综合评价,研究了钴富集特性,并探讨了植物收割的最佳方法。利用已筛选得到的具有植物促生作用的钴抗性专性菌株,与植物构建微生物-植物联合修复土壤钴污染的技术。主要结果如下:(1)在高浓度Co2+(100mg/L)胁迫土壤条件下从32种草坪植物中筛选出了4种草坪植物,其在土壤Co2+胁迫作用下具有明显的生长优势和优良抗性,它们分别是高羊茅(Festucaelata Keng ex E.Alexeev);一年生黑麦草(Loliummultiflorum Lam.);提摩西草(Uraria crinita(L.)Desv.ex DC.);鸭茅(Da ct ylis glo m erat a L.)。低浓度(5m g/L)的Co2+处理下,种草坪植物的相对发芽率,相对发芽势,相对发芽指数,相对活力指数均表现出了增大的趋势,表明低浓度的Co2+对植物萌发具有一定的促进作用。与此不同的是,高浓度(50mg/L、100mg/L)的Co2+处理对植物发芽具有抑制作用。高羊茅种子在高浓度Co2+处理下其相对发芽率,相对发芽势,相对发芽指数,相对活力指数较其他3种植物,表现出了较好的Co2+耐受能力。研究利用权重赋值法考察了四种草坪植物种子萌发Co2+耐受能力,并作出Co2+耐受性综合评价值。四种草坪植物种子萌发期钴耐受能力为高羊茅鸭茅一年生黑麦草提摩西草。(2)随着钴处理浓度的增加,四种草坪植物的相对电导率,脯氨酸,丙二醛,超氧自由基均表现出了增大的趋势,这说明随着Co2+处理浓度的提高,植物所受到的损害也相应的越来越大。高羊茅和提摩西草的叶绿素含量呈现先增后降的趋势,当Co2+处理浓度在50 mg?kg-1以下时,叶绿素含量随着Co2+处理浓度的提高而逐渐增大,当达到50 mg?kg-1以上时,叶绿素含量下降显著。说明低浓度的Co2+处理浓度对高羊茅和一年生黑麦草的叶绿素合成有一定的促进作用,反之,当Co2+浓度过高时会抑制叶绿素的合成。黑麦草和鸭茅其叶绿素含量随着钴浓度的增加而下降,低浓度时下降并不明显,高浓度时下降显著,说明这两种植物钴的耐受性较其他两种弱。对于可溶性蛋白,可溶性糖来说,黑麦草和提摩西草的含量随着钴处理浓度的提高,出现了逐步下降的趋势,说明这两种植物钴的耐受性较弱。高羊茅出现了先增加再下降的趋势,说明随着钴处理浓度的增加高羊茅为了应对所受到的胁迫,可溶性糖可溶性蛋白含量增加,当处理浓度达到高浓度时,高羊茅受到的损害严重,可溶性糖可溶性蛋白含量减少。对4种草坪植物生理生化及其表观生长指标进行主成分分析和权重分析,得到了四种草坪植物苗期的Co2+耐受性综合评判值,四种草坪植物成苗期钴耐受能力为高羊茅提摩西草鸭茅一年生黑麦草。(3)实验条件下对植物Co2+富集量进行估算,研究发现地上多次割茬的采收方法,与其他方法比较可以有效降低土壤中Co2+含量,又可以较少种植次数,减少人工成本。土壤Co2+含量为100mg/kg时,高羊茅地上部分每年每公顷Co2+离子去除量约为2.36kg,土壤Co2+去除率为1.56%;一年生黑麦草地上部分每年每公顷Co2+去除量约为3.11kg,土壤Co2+去除率为1.85%。(4)高羊茅,一年生黑麦草与蜡样芽孢杆菌,枯草芽孢杆菌和苏云金杆菌三个菌种组成的配伍组合是植物微生物联合修复体系里相对最佳的修复组合。在土壤Co2+含量为50mg/kg和100mg/kg时,钴离子土壤去除能力分别会再提升14.01%,8.46%和16.48%,12.91%。综上所述,高羊茅,一年生黑麦草与蜡样芽孢杆菌,枯草芽孢杆菌和苏云金杆菌三个菌种组成的配伍组合是植物微生物联合修复体系里相对最佳的修复组合,土壤钴离子去除率可以提升15%左右。
[Abstract]:In recent years, plant microbes have combined to repair heavy metals contaminated soil. This method has become a new method of remediation. This method has made full use of the advantages of heavy metal hyperconcentration plant repair and microbial remediation by using the mutualism of soil microbial plants to improve the efficiency of soil remediation. In this study, 32 turf plants were screened under the condition of high soil concentration Co2+ stress, and 4 kinds of lawn plants with relatively good growth traits and cobalt resistance were screened. The cobalt tolerance ability of the 4 turf plants was evaluated by the advanced biometric method, and the cobalt rich was studied. The best method of plant harvesting was discussed. Using the selected co resistant specific strains with plant growth promoting effect, the technology of CO remediation of soil cobalt with plant construction microorganism plants was used. The main results were as follows: (1) 4 species of turf plants were screened from 32 turf plants under high concentration of Co2+ (100mg/L) coerced soil. Turf plants have obvious growth advantages and excellent resistance under the stress of soil Co2+ stress. They are tall fescue (Festucaelata Keng ex E.Alexeev), annual ryegrass (Loliummultiflorum Lam.), and Timothy grass (Uraria crinita (L.) Desv.ex DC.). The relative germination rate, relative germination potential, relative germination index and relative vigor index of turf plants showed an increasing trend, indicating that low concentration of Co2+ had a certain promotion effect on plant germination. Different from this, the Co2+ treatment of high concentration (50mg/L, 100mg/L) could inhibit the germination of plants. The seeds of tall fescue were in high concentration. The relative germination rate, relative germination potential, relative germination index and relative vigor index were better than the other 3 plants, and the tolerance ability of the seed germination of Four Turf plants was investigated by weight assignment method. The Co2+ tolerance of the seed germination of Four Turf plants was evaluated, and the seed germination of four kinds of turf plants was given by the weight assignment method. (2) the relative conductivity of four kinds of turf plants, proline, malondialdehyde and superoxide free radicals all showed an increasing trend with the increase of cobalt concentration, which showed that the damage of plants was also higher and higher as the concentration of Co2+ treatment increased. The chlorophyll content of Fescue and Timothy grass increased first and then decreased. When the concentration of Co2+ treatment was below 50 mg? Kg-1, chlorophyll content gradually increased with the increase of Co2+ treatment concentration. When it reached 50 mg? Kg-1, the chlorophyll content decreased significantly. The low concentration of Co2+ treatment concentration for Tall Fescue and annual ryegrass Chlorophyll synthesis has a certain promotion effect. On the contrary, when the concentration of Co2+ is too high, the chlorophyll content will be inhibited. The chlorophyll content of ryegrass and duck grass decreases with the increase of cobalt concentration, and the decrease is not obvious when the low concentration is low, which indicates that the tolerance of the two plants is weaker than the other two kinds of soluble proteins. As for soluble sugar, the content of ryegrass and Timothy grass increased gradually with the increase of cobalt concentration, which showed that the tolerance of the two plants was weak. The high fescue appeared to increase first and then decline, indicating that with the increase of cobalt treatment concentration, the tall fescue was soluble in soluble sugar soluble sugar. When the content of sex protein increased, the damage of tall fescue was seriously damaged and soluble sugar soluble protein content decreased when the concentration reached high concentration. The principal component analysis and weight analysis of the physiological and biochemical and apparent growth indexes of 4 lawn plants were carried out, and the comprehensive evaluation value of Co2+ tolerance for four lawn plants and four kinds of turf planting were obtained. The tolerance ability of cobalt at seedling stage was the annual ryegrass of fescue Timothy grass. (3) under the experimental condition, the enrichment of plant Co2+ was estimated. The study found that the harvest method of multiple stubble harvesting on the ground can effectively reduce the content of Co2+ in the soil, and can reduce the planting times, reduce the artificial cost and the soil Co2+ content. For 100mg/kg, the removal of Co2+ ion per hectare per hectare per hectare is about 2.36kg per hectare per hectare, and the Co2+ removal rate of soil is 1.56% per hectare per hectare. The annual Co2+ removal rate per hectare per hectare on the annual rye grassland is 3.11kg, the soil Co2+ removal rate is 1.85%. (4) tall fescue, annual ryegrass and Bacillus cereus, Bacillus subtilis and Bacillus thuringiensis The combination of three strains of bacteria is the best combination in the plant microbial combined repair system. When soil Co2+ content is 50mg/kg and 100mg/kg, the removal capacity of cobalt ion soil will be increased by 14.01%, 8.46% and 16.48% respectively. Tall fescue, one year old Ryegrass with Bacillus cereus, Bacillus subtilis The combination of three strains of Bacillus thuringiensis is the best combination in the plant microbial combined repair system, and the removal rate of soil cobalt ion can be increased by about 15%.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X53;S688.4

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