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论文题名(中文):

 铅低累积植物的筛选及其耐性研究

作者:

 白彦真

论文语种:

 chi

学科名称:

 土壤学

学位:

 农学硕士

学校:

 山西农业大学

院系:

 资源环境学院

专业:

 土壤学

研究方向:

 土壤与环境

第一导师姓名:

 谢英荷

论文完成日期:

 2006-06-01

论文题名(外文):

 Screening of low lead accumulation plants and

关键词(中文):

  低累积植物 耐性

关键词(外文):

 lead low accumulation plants resistance

论文文摘(中文):

本研究在不同铅浓度处理下,通过对14种植物进行盆栽试验,试图从中筛选出铅低累积植物,并结合其植物生长发育、生理性状、氮磷钾含量、土壤生物活性等各项指标对其耐性进行研究,以期为重金属铅污染土壤的植物修复提供理论依据和有效途径。试验结果表明:

1)经过初步筛选,选出6种植物分别为鸭茅(Dactylis glomerata L.)、虎尾草(Chloris virgata Swartz)、藜(Chenopodium album L.)、新麦草(Psathyrostachys Nebski)、紫苑(Aster tataricus L.f.)、反支苋(Amaranthus retroflexus L.)。这6种植物在土壤铅浓度达国家土壤环境三级标准(500mg/Kg)时,其植株铅含量小于国家饲料卫生标准中复合预混合饲料标准(≤40mg/Kg, 1%添加量计算)。

2)初筛的六种植物继续盆栽试验,结果表明:在土壤铅浓度为500 mg/Kg时,鸭茅、虎尾草、紫苑的生长发育、生理性状、氮磷钾含量等各项指标均未受到铅的抑制,在土壤铅浓度为1000 mg/Kg1500mg/Kg时,生理性状、氮磷钾含量不同程度的受到铅的抑制。藜、新麦草在各个铅处理下均未受到铅的抑制。

3)各种植物土壤细菌、真菌、放线菌数量随着铅浓度的升高呈下降的趋势。在各个铅浓度处理下,藜、新麦草土壤微生物数量下降幅度不明显,其它四种植物下降幅度较大。各种植物在各个铅浓度水平下对土壤过氧化氢酶活性均有激活作用,藜、新麦草激活作用最强,比对照高出33%92%。各种植物在各个铅浓度水平下对土壤碱性磷酸酶有抑制作用,藜、新麦草土壤碱性磷酸酶的抑制最小,其活性为对照的95%99%。各种植物土壤脲酶活性与对照相比,无明显差异。

4)藜、新麦草在各个铅处理下可交换态铅占全铅百分比在2.0%2.8%之间,低于其它四种植物;残渣态铅占全铅百分比在32.4%38.6%之间,高于其它四种植物。相对于其它植物而言,藜、新麦草有着较强的促进土壤固定铅的能力,并且随着土壤铅浓度的增加,其土壤难溶态铅比例增大。

5)在土壤铅浓度为500 mg/Kg时,鸭茅、虎尾草、藜、新麦草、紫苑植株铅含量均未超出国家饲料卫生标准中复合预混合饲料标准。藜、新麦草植株铅含量在各处理中均小于国家饲料卫生标准中复合预混合饲料标准,植株铅含量/根系铅含量(S/R)为各植物中最低,在0.090.13之间,说明铅在这两种植物体内转化运移较差。

通过盆栽试验可以看出,藜、新麦草在本试验各种铅浓度下其植株铅含量均小于国家饲料卫生标准中复合预混合饲料标准,并且生长发育、生理指标、养分状况等均未明显下降,表现出较强的耐性,是本试验筛选出的耐性较强的铅低累积植物。鸭茅、虎尾草、紫苑在土壤铅浓度为500 mg/Kg时,其耐性较强,累积铅较低。这一研究结果将为不同程度铅污染土壤的植物修复及综合利用提供了一定的理论依据和有效途径。

文摘(外文):

 In this research, under different lead concentrations treatment, lead resistance were studied combined with parameters such as plant growth development, physiological characteristics, concentration of nitrogen, phosphate and potassium, and soil biological activity by pot experiments of 14 kinds of plants, attempting to screen lead low accumulation plants to offer theoretic basis and efficient approaches for plant restoration of soil polluted by lead. The results demonstrate:

1By primary screenings,6 kinds of plants were selected and results were: Dactylis glomerata L., Chloris virgata Swartz, Chenopodium album L., Psathyrostachys Nebski ,  Aster tataricus L.f. and Amaranthus retroflexus L. .When lead concentration of the 6 kinds of plants reaches third environmental quality standard for soils500mg/Kg, lead concentration of shoot is smaller than mixed feeds standard≤40mg/Kg, count according to 1% adding amountsin hygienical standard for feeds.

2The 6 kinds of plants after primary screening continued to be in pot experiments, the results indicate that: when lead concentration in soil is 500 mg/Kg, parameters such as plant growth development, physiological characteristics and concentration of nitrogen, phosphate and potassium of Dactylis glomerata L., Chloris virgata Swartz and Aster tataricus L.f. are all not restrained by lead, when lead concentration in soil is 1000 mg/Kg and 1500mg/Kg, physiological characteristics, and concentration of nitrogen, phosphate and potassium are restrained by lead in different extent. Chenopodium album L and Psathyrostachys Nebski are all not restrained by lead in each lead concentration treatment.

3The amounts of bacteria, Fungus and Ray-fungus in soil in all plants decreases as lead concentration increasing. In each lead concentration treatment, the decrease of amounts of microbe in Chenopodium album L.and Psathyrostachys Nebski is not obvious, the decrease of the other four plants is significant. In each lead concentration level all plants have stimulation function to catalase activity in soil. Stimulation function in Chenopodium album L.and Psathyrostachys Nebski is highest, increased 33%92% compared with controls. In each lead concentration level all plants have restraint function to alkaline phosphatese activity in soil. Restraint function in Chenopodium album L.and Psathyrostachys Nebski is lowest, activity in which is 95%99% of which. Compared with controls, in all plants soil urease activity have not obvious difference.

4In each lead concentration treatment, the content of exchangeable Pb is 2.0%2.8% compared with total Pb in Chenopodium album L.and Psathyrostachys Nebski, which is lower than the other four plants. The content of residual Pb is 32.4%38.6% compared with total Pb in Chenopodium album L.and Psathyrostachys Nebski, which is higher than the other four plants. Relatively, Chenopodium album L.and Psathyrostachys Nebski have strong acceleration function in   fixing Pb of soil. Sparingly soluble Pb increases as lead concentrations increasing.

5) When lead concentration in soil is 500 mg/Kg, lead content of shoot in Dactylis glomerata L., Chloris virgata Swartz, Chenopodium album L., Psathyrostachys Nebski and Aster tataricus L.f. is smaller than mixed feeds standard in hygienical standard for feeds. In each lead concentration treatment, lead content of shoot in Chenopodium album L. and Psathyrostachys Nebski is smaller than mixed feeds standard in hygienical standard for feeds and lead content of shoot/ lead content of root is 0.090.13, lowest in 6 plants, demonstrates transformations and movements of lead in the 2 plants are poor.

Studied by pot experiments, we can see: in this research, under different lead concentrations treatment, lead content of shoot in Chenopodium album L. and Psathyrostachys Nebski is all smaller than mixed feeds standard in hygienical standard for feeds and growth development, physiological characteristics and nutrients condition are all not obvious decreased. Chenopodium album L.and Psathyrostachys Nebski display strong resistance, which are lead low accumulation plants with strong resistance screened in this research. When lead concentration in soil is 500 mg/Kg, Dactylis glomerata L., Chloris virgata Swartz and Aster tataricus L.f. display strong resistance and lead accumulation is low. This result can offer theoretic basis and efficient approach for plant restoration and comprehensive utilization of soil polluted by lead in different extent.

开放日期:

 2007-06-01

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