柳树水培扦插对水体重金属污染修复作用研究
发布时间：2020-11-04 08:22
重金属可在土壤或水体中富集,并通过植物吸收在生物体中积累,随着食物链从低营养级向高营养级逐步累积,对环境和人类的健康造成极大的危害。在诸多土壤和水体重金属污染修复技术中,植物修复成本低,对环境零危害,是非常有效的修复技术。木本植物柳树因其具有巨大的生物量,快速的生长速率和较强的适应性,被广泛应用于土壤重金属污染修复中。柳树以水培的方式进行扦插繁殖有一定优势。本文主要以柳树对重金属的富集为基础,从实际应用的角度出发,通过比较三种柳树对不同浓度的复合重金属污染水体的耐受性和富集性差异,研究重金属的交互作用对柳树富集转运重金属能力的影响,分析四种重金属等量单独胁迫对柳树逆境生理指标的影响,探讨柳树插条对重金属和磷复合污染水体的修复能力以及用于水体重金属污染修复的柳树插条移栽到铅锌矿区用于土壤重金属修复的可行性。主要研究结果如下:(1)三种柳树在水体中均能短时间内生根发芽。与旱柳和垂柳相比,竹柳在非污染水体中生长最好,在污染水体中生长最差,地上及地下部位对复合重金属的耐受性指数分别为43和40;旱柳尽管在非污染水体中生长不是最好,但在重金属混合的污染水体中生长最好,地上及地下部位对复合重金属耐受性指数分别为75和90。随着复合重金属处理浓度增大,品种之间的耐受性差异也增大。旱柳对复合重金属污染具有较强的耐受性,其木质茎插条能够富集重金属,阻止重金属向新生枝条部位的转移。此结果表明,柳树不同品种的生长状况并不能反映出其对重金属的富集能力。(2)三种柳树在生根前,原始木质茎插条具有富集重金属的能力,其能力的大小与插条直径和插条来自于母本的位置有关。在单一重金属Cd处理下,直径大于1cm的插条,其地上和地下生物量分别为0.21g和0.04g,耐受性指数分别为74和82,对重金属Cd的富集系数为0.12;而直径小于1cm的插条,其地上和地下生物量分别为0.05g和0.02g,耐受性指数分别为40和50,对重金属Cd的富集系数为0.01。由此可说明,旱柳原始木质茎插条直径越大,其在重金属污染环境中生长越好,具有更高的重金属耐受性和重金属富集能力。三个品种的柳树中,与来自于原始木质茎底部的插条相比,来自于顶部的插条在复合重金属处理前后都表现出较差的生长参数,但其新生枝条富集重金属的含量却较高。同样时间内,来自顶部的旱柳插条对Cd、Cu、Pb和Zn的富集含量分别为5.7,20.8,20.2和101.8 μg/plant;而来自基部的旱柳插条对四种重金属的富集含量分别为2.9,10.5,10.4和53.3μg/plant。以上结果表明,同种柳树,不同的插条会呈现出不同的生长状况及重金属富集能力,其中,后两者的相关性也存在差异。(3)与未生根的插条相比,旱柳根系的存在会改变重金属Cd和Cu在各部位的分布及二者的相互作用,同时也会提高旱柳对重金属的耐受性和富集能力。无根系的旱柳对Cu的耐受性为38,富集系数为0.15;具根系的旱柳对Cu的耐受性为67,富集系数为0.45。重金属Cu会抑制旱柳对重金属Cd的富集,却会促进Cd向新生枝条的转移,添加重金属Cu后,Cd由木质茎到新生枝条的转移系数由13.5增加为22.5。插条未生根时,重金属Cd抑制Cu向新生枝条的转运,却促进插条对Cu的富集;而在插条生根后,重金属Cd仅抑制根系对重金属Cu的吸收。添加重金属Cd后,无根系的插条对Cu的富集系数增加为0.2,有根系的插条对Cu的富集系数减少为0.36。(4)单一及混合重金属Cd和Zn处理两周后,旱柳根茎的相对伸长量及生物量并未受到显著影响,但其生理功能却受到伤害。叶绿素a和叶绿素b的含量在所有处理中均降低,而植物根系活力仅在Cd-Zn50和Cd-Zn100处理中降低,根茎SOD和POD活性仅在单一 Cd和Cd-Zn50处理中增强。重金属Cd和Zn在地上部位的积累总量由植物部位和重金属处理共同决定,Cd-Zn50处理下,Cd和Zn在叶片中的积累量为64mg/kg和97mg/kg,而在韧皮部中分别为161mg/kg和371mg/kg;在单一 Cd、Cd-Zn50和Cd-Zn200处理下,重金属Cd在地上部位的积累量分别为93mg/kg、84mg/kg和68 mg/kg。无论哪种重金属处理,重金属Cd和Zn均在韧皮部富集最多,在木质部最少。另外,重金属Cd和Zn在植物的吸收转运中存在交互作用,具体表现为Zn抑制Cd在旱柳地上部位的富集,Cd促进Zn在旱柳地上部的积累。(5)在相对较短的生长时期,同种浓度的四种重金属处理对旱柳新生茎和根的相对伸长量、鲜重和干重的影响不大,但却激发了植物根茎生理的响应。四种重金属处理均增大了根茎的POD活性和可溶性蛋白含量,降低了叶绿素含量,其中Cu对叶绿素的影响最大;重金属Zn降低了根系活力,而Pb却增大了根系活力;重金属Cu和Pb增大了游离脯氨酸的含量;四种重金属处理均在不同程度上增大了旱柳体内的SOD活性,且均尚未影响植物体的MDA含量。旱柳对同种浓度的四种重金属具有不同的向上转运能力,叶片中Zn含量为98mg/kg,远大于叶片中Pb的含量(0.15mg/kg),大部分重金属转运至地上部位后,被储存在植物的韧皮部。这些生理性变化的差异性一定程度上揭示了旱柳对逆境过程的生理响应和适应机制。(6)为了提高柳树对重金属的富集能力,研究了叶面施加磷肥对柳树富集重金属的作用。结果表明,叶面喷施磷肥会促进旱柳地上部位的生长和Cd从根系向地上部位的转运,增强旱柳地下及地上部位对Cd的富集总量。此结果提示,旱柳作为水体重金属修复植物时,在根系和叶面同时施加磷,不但能够增强旱柳对重金属的耐受性,而且能够提高旱柳对重金属Cd的富集效率。(7)水培的柳树随着培养时间的增加,水体环境不能满足柳树的继续生长,因此可考虑将这些插条移植到土壤中,研究其对土壤重金属的富集作用。结果表明,将旱柳插条水培三周,其地上及地下生物量分别为0.159g和0.056g;采用土培方式培养三周,其地上及地下生物量则为0.104g和0.035g。采用水培与土培结合的方式培养旱柳,能大大提高旱柳的生物量,并且移栽至土壤后的成活率可达75%以上。水培1周,旱柳地上生物量为0.066g,转移到污染土壤中生长3周,其地上生物量增长率为342%(1W;1W-3S);水培2周旱柳地上生物量为0.123g,转移到污染土壤中生长2周,其地上生物量增长率为454%(2W;2W-2S)。不同的前期预胁迫方式和预胁迫的时间会导致植物转移到污染土壤后的总叶绿素含量,POD活性和根系活力呈现差异,这种差异是植物适应环境的正常响应。预水培处理的插条均比直接种植在污染土壤中的插条生物量增长更大,对污染环境的适应性更强。由此可见,将水培一段时间之后的旱柳插条移栽到污染土壤的方法可行的。综上所述,采用工厂化水培扦插技术进行柳树繁殖,柳树插条能够吸收水体中的重金属,并且修复效果良好。柳树富集水体重金属的能力因柳树品种、插条特性及重金属种类的不同而呈现差异,其中旱柳和垂柳插条对重金属Cd、Cu和Zn富集能力较强;在柳树插条生根之前,其木质茎插条具有富集水体中重金属Cd和Cu的能力,水体中各重金属的相互作用会因根系的产生而发生变化;为减轻重金属对旱柳的伤害,旱柳根茎中与抗逆性有关的酶活性增大,可溶性蛋白含量提高,叶绿素含量降低,其中Cu对叶绿素的伤害最大,Cd、Cu、Zn和Pb四种重金属转运至地上部位后,大部分被储存在植物的韧皮部;柳树的水培扦插繁殖技术可用于修复重金属污染的水体,叶面磷肥的添加能够增强旱柳对重金属Cd的富集能力,并且用于水体重金属污染修复的柳树在一段时间后可以移植到矿区用于矿区土壤修复。
【学位单位】：南京大学
【学位级别】：博士
【学位年份】：2017
【中图分类】：X52;S792.12
【文章目录】：
摘要
Abstract
Chapter 1 Introduction
1.1 Heavy metal pollution and remediation
1.1.1 Sources and harmful effects of heavy metals pollution
1.1.2 Remediation of heavy metals pollution
1.2 Phytoremediation
1.2.1 Define of phytoremediation
1.2.2 Plants selection for phytoremediation
1.3 Application and research of Salix in phytoremediation
1.3.1 Application of Salix in phytoremediation
1.3.2 Factors in accumulation and transportation of heavy metals by Salix
1.3.3 Heavy metals accumulation in plant tissues
1.4 Research objectives
Chapter 2 Effect of heavy metals combined stress on growth and metalsaccumulation of three Salix species with different cutting position
2.1 Introduction
2.2 Materials and methods
2.2.1 Plant materials and treatments
2.2.2 Growth parameters and Tolerance index （Ti） measurement
2.2.3 Heavy metal and Translocation factor （TF） analyses
2.2.4 Statistical analysis
2.3 Results and discussion
2.3.1 Growth parameters, biomass production, and Tolerance index ofSalix species
2.3.2 HM accumulation and above-ground TF-aerial of the Salix species
2.3.3 Growth parameters of different cutting position
2.3.4 HM content in different cutting positions
2.4 Conclusion
Chapter 3 Phytoextraction of initial cutting of S. matsudana for Cd and Cu
3.1 Introduction
3.2 Materials and methods
3.2.1 Plant materials and treatments
3.2.2 Growth parameters and Relative growth rate （RGR） determination
3.2.3 Biomass and Tolerance index （Ti） measurement
3.2.4 Heavy metal and Translocation factor （TF） analyses
3.2.5 Phytoextraction capacity （PC） analysis
3.2.6 Statistical analysis
3.3 Results and Discussion
3.3.1 Effect of cutting diameter on willow growth and its HMabsorptivity
3.3.2 Root system function in vegetation filters
3.3.3 Phytoextraction intensity of initial cuttings without rhizofiltration
3.3.4 Interactions between Cd and Cu in phytoremediation
3.4 Conclusion
Chapter 4 Effects of single and compound Cd and Zn treatment on the growth andphysiology of S. matsudana
4.1 Introduction
4.2 Materials and methods
4.2.1 Plant materials and treatments
4.2.2 Biomass production and Relative growth rate （RGR） determination
4.2.3 Heavy metal analyses
4.2.4 Enzyme activity measurement
4.2.5 Chlorophyll measurement
4.2.6 Root activity
4.2.7 Statistical analysis
4.3 Result and Discussion
4.3.1 RGR and biomass of S. matsudana with single and compoundstress of Cd and Zn
4.3.2 Chlorophyll content and Root activity of S. matsudana with singleand compound stress of Cd and Zn
4.3.3 Antioxidant enzymes activity of S. matsudana with single andcompound stress of Cd and Zn
4.3.4 Heavy metals concentration in different tissues of S. matsudanawith single and compound stress of Cd and Zn
4.4 Conclusion
Chapter 5 Effects of single heavy metal stress on the growth and physiology of S.matsudana under unity concentration of lead, cadmium, zinc and copper
5.1 Introduction
5.2 Materials and methods
5.2.1 Plant materials and treatments
5.2.2 Biomass production and Relative growth rate （RGR） determination
5.2.3 Heavy metal analyses
5.2.4 Enzyme activity measurement
5.2.5 Chlorophyll measurement and root activity
5.2.6 Estimation of lipid peroxidation
5.2.7 Soluble protein measurement
5.2.8 Free proline measurement
5.2.9 Statistical analysis
5.3 Result and Discussion
5.3.1 RGR and biomass of S. matsudana with different heavy metaltreatments
5.3.2 Total chlorophyll content of S. matsudana with different heavymetal treatments
5.3.3 Free proline content and root activity of S. matsudana withdifferent heavy metal treatments
5.3.4 Antioxidant enzymes activity of S. matsudana with different heavymetal treatments
5.3.5 MDA and soluble protein content of S. matsudana with differentheavy metal treatments
5.3.6 Heavy metals concentration in different tissues of S. matsudanawith different heavy metal treatments
5.4 Conclusion
Chapter 6 Effect of P fertilization on the growth and heavy metal accumulation of S.matsudana
6.1 Introduction
6.2 Materials and methods
6.2.1 Plant materials and treatments
6.2.2 Growth parameters and Relative growth rate （RGR） determination
6.2.3 Biomass and Tolerance index （Ti） measurement
6.2.4 Heavy metal and Translocation factor （TF） analyses
6.2.5 Statistical analysis
6.3 Results and discussion
6.3.1 Growth and biomass of S. matsudana
6.3.2 Weekly data of Salix matsudana with P and Cd addition treatment
6.3.3 Tolerance index （Ti） and Translocation factor （TF） of Salixmatsudana
6.3.4 Concentration and content of Cd in Salix matsudana with P and Cdaddition treatment
6.4 Conclusion
Chapter 7 Effect of hydroponic pre-treatment on growth and physiology of Smatsudana after transplant to contaminate soil
7.1 Introduction
7.2 Materials and methods
7.2.1 Plant materials and treatments
7.2.2 Biomass production and Relative growth rate （RGR） determination
7.2.3 Physiological index measurement
7.2.4 Statistical analysis
7.3 Result and Discussion
7.3.1 RGR of S. matsudana in different water culture
7.3.2 Moisture content of S. matsudana in different treatments andculture ways
7.3.3 Biomass production of S. matsudana before and after transplant tocontaminate soil
7.3.4 Total chlorophyll content in leaves of S. matsudana in differenttreatments and culture ways
7.3.5 Antioxidant enzymes activity of S. matsudana in differenttreatments and culture ways
7.3.6 Root activity of S. matsudana in different treatments and cultureways
7.4 Conclusion
Chapter 8 Summary
8.1 Conclusions
8.2 Prospects
References
List of publications （September 2013-December 2016）
Acknowledgments
本文编号：2869872
【学位单位】：南京大学
【学位级别】：博士
【学位年份】：2017
【中图分类】：X52;S792.12
【文章目录】：
摘要
Abstract
Chapter 1 Introduction
1.1 Heavy metal pollution and remediation
1.1.1 Sources and harmful effects of heavy metals pollution
1.1.2 Remediation of heavy metals pollution
1.2 Phytoremediation
1.2.1 Define of phytoremediation
1.2.2 Plants selection for phytoremediation
1.3 Application and research of Salix in phytoremediation
1.3.1 Application of Salix in phytoremediation
1.3.2 Factors in accumulation and transportation of heavy metals by Salix
1.3.3 Heavy metals accumulation in plant tissues
1.4 Research objectives
Chapter 2 Effect of heavy metals combined stress on growth and metalsaccumulation of three Salix species with different cutting position
2.1 Introduction
2.2 Materials and methods
2.2.1 Plant materials and treatments
2.2.2 Growth parameters and Tolerance index （Ti） measurement
2.2.3 Heavy metal and Translocation factor （TF） analyses
2.2.4 Statistical analysis
2.3 Results and discussion
2.3.1 Growth parameters, biomass production, and Tolerance index ofSalix species
2.3.2 HM accumulation and above-ground TF-aerial of the Salix species
2.3.3 Growth parameters of different cutting position
2.3.4 HM content in different cutting positions
2.4 Conclusion
Chapter 3 Phytoextraction of initial cutting of S. matsudana for Cd and Cu
3.1 Introduction
3.2 Materials and methods
3.2.1 Plant materials and treatments
3.2.2 Growth parameters and Relative growth rate （RGR） determination
3.2.3 Biomass and Tolerance index （Ti） measurement
3.2.4 Heavy metal and Translocation factor （TF） analyses
3.2.5 Phytoextraction capacity （PC） analysis
3.2.6 Statistical analysis
3.3 Results and Discussion
3.3.1 Effect of cutting diameter on willow growth and its HMabsorptivity
3.3.2 Root system function in vegetation filters
3.3.3 Phytoextraction intensity of initial cuttings without rhizofiltration
3.3.4 Interactions between Cd and Cu in phytoremediation
3.4 Conclusion
Chapter 4 Effects of single and compound Cd and Zn treatment on the growth andphysiology of S. matsudana
4.1 Introduction
4.2 Materials and methods
4.2.1 Plant materials and treatments
4.2.2 Biomass production and Relative growth rate （RGR） determination
4.2.3 Heavy metal analyses
4.2.4 Enzyme activity measurement
4.2.5 Chlorophyll measurement
4.2.6 Root activity
4.2.7 Statistical analysis
4.3 Result and Discussion
4.3.1 RGR and biomass of S. matsudana with single and compoundstress of Cd and Zn
4.3.2 Chlorophyll content and Root activity of S. matsudana with singleand compound stress of Cd and Zn
4.3.3 Antioxidant enzymes activity of S. matsudana with single andcompound stress of Cd and Zn
4.3.4 Heavy metals concentration in different tissues of S. matsudanawith single and compound stress of Cd and Zn
4.4 Conclusion
Chapter 5 Effects of single heavy metal stress on the growth and physiology of S.matsudana under unity concentration of lead, cadmium, zinc and copper
5.1 Introduction
5.2 Materials and methods
5.2.1 Plant materials and treatments
5.2.2 Biomass production and Relative growth rate （RGR） determination
5.2.3 Heavy metal analyses
5.2.4 Enzyme activity measurement
5.2.5 Chlorophyll measurement and root activity
5.2.6 Estimation of lipid peroxidation
5.2.7 Soluble protein measurement
5.2.8 Free proline measurement
5.2.9 Statistical analysis
5.3 Result and Discussion
5.3.1 RGR and biomass of S. matsudana with different heavy metaltreatments
5.3.2 Total chlorophyll content of S. matsudana with different heavymetal treatments
5.3.3 Free proline content and root activity of S. matsudana withdifferent heavy metal treatments
5.3.4 Antioxidant enzymes activity of S. matsudana with different heavymetal treatments
5.3.5 MDA and soluble protein content of S. matsudana with differentheavy metal treatments
5.3.6 Heavy metals concentration in different tissues of S. matsudanawith different heavy metal treatments
5.4 Conclusion
Chapter 6 Effect of P fertilization on the growth and heavy metal accumulation of S.matsudana
6.1 Introduction
6.2 Materials and methods
6.2.1 Plant materials and treatments
6.2.2 Growth parameters and Relative growth rate （RGR） determination
6.2.3 Biomass and Tolerance index （Ti） measurement
6.2.4 Heavy metal and Translocation factor （TF） analyses
6.2.5 Statistical analysis
6.3 Results and discussion
6.3.1 Growth and biomass of S. matsudana
6.3.2 Weekly data of Salix matsudana with P and Cd addition treatment
6.3.3 Tolerance index （Ti） and Translocation factor （TF） of Salixmatsudana
6.3.4 Concentration and content of Cd in Salix matsudana with P and Cdaddition treatment
6.4 Conclusion
Chapter 7 Effect of hydroponic pre-treatment on growth and physiology of Smatsudana after transplant to contaminate soil
7.1 Introduction
7.2 Materials and methods
7.2.1 Plant materials and treatments
7.2.2 Biomass production and Relative growth rate （RGR） determination
7.2.3 Physiological index measurement
7.2.4 Statistical analysis
7.3 Result and Discussion
7.3.1 RGR of S. matsudana in different water culture
7.3.2 Moisture content of S. matsudana in different treatments andculture ways
7.3.3 Biomass production of S. matsudana before and after transplant tocontaminate soil
7.3.4 Total chlorophyll content in leaves of S. matsudana in differenttreatments and culture ways
7.3.5 Antioxidant enzymes activity of S. matsudana in differenttreatments and culture ways
7.3.6 Root activity of S. matsudana in different treatments and cultureways
7.4 Conclusion
Chapter 8 Summary
8.1 Conclusions
8.2 Prospects
References
List of publications （September 2013-December 2016）
Acknowledgments
本文编号：2869872
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