【作者】 孙琴；

【导师】 倪吾钟； 罗安程；

【作者基本信息】 浙江大学 ， 植物营养学， 2002， 硕士

【摘要】 植物修复已被视为重金属污染土壤治理的有效技术之一，超积累植物是重金属污染土壤植物修复技术的基础，合理施肥则是提高植物修复效率的主要技术措施之一。本文以原产于我国的Zn超积累植物—东南景天(Sedum alfredii Hance)为试材，综合运用溶液培养、差速离心技术以及盆栽试验等方法研究了磷对超积累植物东南景天生长、吸收和积累锌的影响，初步结果如下： 1．溶液培养条件下，在本试验所设置的锌处理水平范围内，提高营养液中的磷浓度(0-2.0 mmol／L)，东南景天趋于明显的旺盛生长、生物量(以干物计)显著增加，并在1200μmol／L高锌处理下更为显著。东南景天地上部叶片和茎中磷-锌正交互作用也达到显著水平。 2．在一定的磷浓度范围内(0-1.0mmol／L)增磷，东南景天叶片、茎的含锌量和锌吸收量均随溶液中磷浓度的提高而显著增加，并随锌水平的提高效果越明显，高磷(≧2.0 mmol／L)则有所降低，但仍高与对照；东南景天根系的含锌量和锌吸收量均随磷锌水平的提高而显著增加；显著地提高S／R比值(地上部锌的吸收量／根部锌的吸收量)，且无论在何种磷锌处理下，东南景天地上部的锌吸收量均高于根部。 3．东南景天体内锌的分布特征为：器官水平上—地上部(75-95％)＞根(5-23％)，叶片和茎中锌的分配比例相当，约占30-50％左右；细胞水平上—细胞壁为叶片细胞内锌的主要分布位点，约占40-60％，细胞器及质膜和细胞壁为茎细胞内锌的主要分布位点约占75-85％，叶片和茎细胞内可溶性成分锌维持在稳定的水平，前者约占20-30％，后者占20％左右，根细胞内锌大多数以可溶性成分(以液泡液为主)和细胞壁为主，约占60-95％。 4．不同磷水平对东南景天体内锌的分布影响：器官水平上—增磷显著地提高了茎中锌的分配比例，并随锌水平的提高效果越显著；增磷对叶片中锌的分配比例影响不大，在高锌下(1200μmol／L)有所降低；增磷显著地降低了根系中锌的分配比例。红胞水平上—增磷提高了东南景天地上部叶片和茎组织细胞壁上锌的分配比例，降低细胞器及质膜上锌的分配比例，细胞内可溶性成分锌的分配比例变化不大或稍有降低；增磷显著地提高了根系细胞壁上锌的分配比例，细胞内可溶性锌和细胞器及质膜上锌的分配比例有所降低。 5．盆栽条件下，适当增施磷肥（31－124 mg P八g土）极显著地增加超积累植物东 南景天地上部的生物量（以干物计）、锌的吸收量、积累量及Zn生物富集系数， 并以 31。s P上s上水平为最佳，但施磷过量（248 mz Phs土）则产生抑制 作用，表明适量施用磷肥能有效地提高东南景天对锌污染土壤的修复能力。更多还原

【Abstract】 Phytoremediation is becoming an established technology for environmental clean-upand protection. Hyperaccumulator plants are potential tools to remove excessive metals in contaminated soils by continuous phytoextraction. Fertilization is one of the main measurements to enhance their ability to extract and accumulate metals from the metal-contaminated soils. Sedum alfredii Hance was identified as a Zn- hyperaccumulator in China (Long et al 2002), which was used as the test plant in this research. As an efficient operational routine technology, phytoextraction requires a better knowledge of the behaviors, such as P-Zn interaction, Zn absorption, accumulation, distribution, and biomass of Sedum alfredii Hance ?<= affected hv P ?J Zn addition. To identify the effects of P and Zn addition on Sedum alfredii Hance, a hydroponic experiment was carried out. And the responses of growth and Zn absorption or accumulation of Sedum alfredii Hance to P fertilization was also investigated using a pot experiment with a polluted soil. The results obtained are summarized as follows:1. In hydroponic experiment, biomass (dry matter) of leaves, stems and roots of Sedum alfredii Hance increased significantly with P supplies from 0.5 to 2.0 mmol/L at all Zn levels, especially at the Zn level of 1200 umol/L. It was also found that the P-Zn interaction on the weight of dry matter in shoots of Sedum alfredii Hance existed significantly.2. Zn contents and absorption in leaves, stems and roots of Sedum alfredii Hance increased significantly with increasing P concentrations in nutrient solution (<1.0 mmol/L for leaves and stems, <2.0 mmol/L for roots) at all Zn levels. Higher P supply (2.0 mmol/L) reduced Zn contents and absorption in leaves and stems of Sedum alfredii Hance. Appropriate P supplies enhanced Zn absorption, translocation from root to shoot and accumulation in shoots as the ratios of shoot Zn absorbed /root Zn absorbed (S/R>1) in Sedum alfredii Hance was significantly increased. Both of "phosphorus-induced Zn requirement" and "antagonistic effect of excessive phosphorus" were found in Sedum alfredii Hance.3. The distribution of Zn absorbed in Sediim alfredii Hance was shoots (75-95%, 30-50% in leaves and 30-50% in stems) > roots (5-23%) in the hydroponic experiment. Subcellar distribution of Zn was also studied with the differential speed centrifigation technique. The results indicated that 40-60% of Zn was in the cell wall for leaf, 75-85% of Zn was in the cell wall and organelle and membrane for stem, and 60-95% of Zn was in the soluble fraction and cell wall for root, implying that the major storage sites of Zn in plant cells are different for the different organs (leaf, stem and root) in Sedum alfredii Hance.4. Zn distribution in hyperaccumulators Sedum alfredii Hance was markedly affected with P addition. P supplies increased the proportion of Zn in shoots through increasing the proportion of Zn in stems, and reduced the proportion of Zn in roots. In cell levels, P supplies increased the proportion of Zn in the cell wall and lowered the proportion of Zn in organelle and membrane for leaves, stems and roots, as well as lowered the proportion of Zn in the soluble fraction for roots. The proportion of Zn in the soluble fraction for leaves and stems were slightly affected by P addition.5. In the pot experiment with a Pb/Zn-comtaminated soil from the vicity of the old Pb/Zn base-metal mine waste in Quzhou City, Zhejiang Province, P. R. China, the effects of P fertilization on the growth, Zn absorption and accumulation in Sedum alfredii Hance were investigated. The results showed that P application ranging 31-124 mgP /kg soil could significantly increase the shoot biomass (dry matter), Zn amounts absorbed and accumulated in shoots of Sedum alfredii Hance and bioaccumulation coefficient (plant/soil Zn concentration ratio). It was also observed that excessive P (248 mgP /kg soil) inhibited growth of Sedum alfredii Hance, as its shoot biomass was lower than that of the control (no P supply). It i更多还原