【作者】 严密；

【导师】 刘登义；

【作者基本信息】 安徽师范大学 ， 生态学， 2007， 硕士

【摘要】 随着工业化、城市化、农业现代化的发展,向土壤中排放的重金属逐年增加,重金属污染已日益成为威胁人类健康和影响人类生活质量的严重的环境问题和社会问题,而铅是其中一种污染性较强的重金属元素。由于工业的活动如铅锌矿的开采和冶炼,使铅锌等重金属排入环境,污染环境。蔬菜区也常常受到铅等重金属污染的影响,蔬菜受到污染后,严重影响其产量和质量,更为严重的是铅等重金属经食物链进入人体,在人体内富集,严重危害人体健康。植物修复技术可以部分地解决这一问题,已在全球范围内成为人们的研究热点,亦是目前仅见的土壤污染治理的环境友好技术。主要包括植物吸取、植物挥发和植物稳定三种方式。超富集植物是重金属胁迫环境对生长于其中的植物长期自然选择的结果,以其具有对重金属的耐性、富集性等展示了它在重金属污染土壤修复方面的巨大潜力。杂草是农业生态系统中的重要生物组成部分,也是影响农林作物生长和导致产量下降的重要因素之一,但保持适量和适宜的杂草多样性,对改善农业生态环境及消除和控制环境污染有重要作用。保持适宜的杂草多样性不仅有保护天敌、控制农业害虫、保持土壤和促进养分循环等生态学功能,而且对消除环境污染也有重要作用。所以本文以常见农田杂草为载体,研究了它们对铅的耐性和富集能力,探讨了对铅污染土壤进行植物修复的可行性,首先对常见24种农田杂草进行初步筛选,通过水培的方法研究铅污染对这24种杂草的基本生理指标的影响,得到3种耐性较强的品种,分别为马唐(Digitaria sanguinalis)、牛筋草(Eleusine indica)和狗尾草(Setaria viridis);接着通过盆栽试验,深入研究了铅对这3种杂草幼苗生长及其抗性生理的影响,筛选出较为优良的耐铅品种马唐和狗尾草,进一步试验分析了土壤重金属铅浓度与土壤基本理化性质、土壤酶活性的关系,以及经这两种杂草修复后土壤理化性质和酶活性的恢复情况。结果表明土壤过氧化氢酶和脲酶活性与土壤铅浓度极显著相关,可表示出土壤受铅污染程度;铅污染土壤经过马唐修复后,过氧化氢酶和脲酶活性均得到恢复,根据它们的活性恢复状况判断出马唐修复效果较好。农田杂草对铅毒害的响应及其耐性机理的研究,为利用其有效地改良铅污染土壤及矿业废弃地的植物修复提供了科学理论依据。更多还原

【Abstract】 With the development of modern industry and agriculture, the release of heavy metals into the environment has been accelerating year by year. Heavy metal contamination poses a threat to human health and life quality, which becomes a serious problem in environment and society, and Pb is one of heavy metal elements with stronger contamination traits. As a result of artificial activities like lead-zinc mine mining and smelting, some heavy metals such as lead and zine are dispersed into the environment, which leads to the environment populated. Vegetables area also frequently is polluted by lead. After this, the output and the quality of vegetable are affected seriously. More serious is that lead enters the human body along the food chain, and concentrates in the human body, which can severely impair human health. This problem may be partially solved by the phytoremediation which offers a cost-effective“green”method for soil remediation. There are now three subsets of this technology applicable to soil remediation :(1) phytoextraction, using hyperaccumulator plants or high biomass metal accumulating plants to remove toxic metals from soil; (2) phytovolatilization, using plants to stimulate volatilization of metals from soil or plant surface; and (3) phytostabilization, using plants to transform soil metals from toxic forms to less toxic forms. Hyperaccumulators are the plants which have been selected by the heavy metals-contaminated environment. It is the tolerance and concentration of heavy metals that demonstrate hyperaccumulators have the ability to remediate soils contaminated by heavy metals. Hyperaccumulators are able to accumulate over 1000mg·kg-1Cu (Pb, Ni etc) or over 100mg·kg-1Cd etc(Dry-Weight).Weeds are important biological constituents in the agriculture ecosystem, and also affect the farming and forestry crops to grow and to cause one of important attributes which the output drops, but maintains right amount and the suitable weed multiplicity, to improves the agriculture ecological environment and the elimination and the control environmental pollution has the vital role. Not only the maintenance being suitable weed multiplicity has the protection natural enemy, control pest, maintenance and promotion nutrient cycle in soil, moreover cancels eliminates the environmental pollution also to have the vital role. Therefore this paper take the common farmland weed as experimental materials, has studied them and concentrates ability to the lead patience, and discussed repair feasibility. First we carried on preliminary screening to the common 24 kinds of farmland weeds. The effect of Lead pollution on the seedling growth, eco-physiological index was studied by means of water cultivation experiments. And then we obtained 3 kinds of patient strong varieties: Digitaria sanguinalis、Setaria viridis and Eleusine indica.Then through the pot experiment, thoroughly has studied the lead to these 3 kinds of weeds seedling growth and the resistant physiological influence, screens finer bears the lead variety Digitaria sanguinalis and Setaria viridis, further experimented has analyzed the soil lead concentration and the soil basic physics and chemistry nature, the soil enzyme activity relations, as well as after these two kind of weeds repair soil physics and chemistry nature and enzyme activity restoration situation. The result indicated the soil catalase and urease activities and the soil lead concentration is extremely remarkable is connected, may express the lead pollution degree; The lead pollution soil after the Digitaria sanguinalis repair, the catalase and urease activities obtains the restoration, is good according to theirs revivification estimate of the situation Digitaria sanguinalis repair effect.Our studies of the responses and mechanism of tolerance of farmland weeds to Pb stress and the achievement in this paper hopefully provide a theoretically scientific basis for utilizing to restore the soil polluted by Pb and phytoremediation in tail-mining wasteland.更多还原