• 关键词：Cu  旱柳  SEM-EDAX  转移  富集

• 基金项目：国土资源部公益性科研项目(No.201011006-1); 国家重点基础研究发展计划(973)项目(No.2007CB407302)

• 朱宇恩
• 1. 北京师范大学环境学院水环境模拟国家重点实验室, 北京 100875;
  2. 山西大学环境与资源学院, 太原 030006

• 赵烨
• 北京师范大学环境学院水环境模拟国家重点实验室, 北京 100875

• 徐东昱
• 北京师范大学环境学院水环境模拟国家重点实验室, 北京 100875

• 闫冬
• 北京师范大学环境学院水环境模拟国家重点实验室, 北京 100875

• 呼红霞
• 北京师范大学环境学院水环境模拟国家重点实验室, 北京 100875

• 李永良
• 北京师范大学分析测试中心, 北京 100875

• 摘要：为探讨重金属元素Cu在旱柳(Salix matsudana Koidz)植物体内的迁移及形态特征,研究通过水培模拟实验,运用ICP-AES测定了旱柳不同组织中Cu含量,并采用SEM-EDAX技术分析了旱柳不同组织显微结构和Cu存在形态.结果表明:在Cu胁迫下,根、茎、叶中Cu含量随培养液Cu浓度的增加而增加,在450 μmol·L^-1浓度下根部Cu含量可达2794 mg·kg^-1,不同组织富集能力顺序为根>叶>茎;旱柳叶中叶绿素含量随培养液Cu浓度增加先小幅上升后大幅下降;SEM-EDAX分析发现,根内Cu主要存在于表皮、中柱及维管束部分,茎内Cu则主要分布在皮层、韧皮部和木质部;Cu含量的增加会抑制旱柳根、茎、叶对Ca、Mg的吸收,使叶绿素含量下降,间接影响了光合作用的正常进行,导致旱柳生物量增长幅度显著降低.

• Abstract：Willows have been shown to be promising for heavy metal phytoextraction. However, the characteristics of migration and distribution of copper in salix matsudana Koidz are still not clearly known. In order to better identify these characteristics, based on hydroponic experiment, the concentrations of Cu in different tissues of Salix matsudana Koidz were measured using ICP-AES, and the microscopic structures of Cu in different tissues were investigated using SEM-EDAX. The results showed that Cu concentrations in roots, stems and leaves increased with the increase of Cu concentrations in culture solutions, and Cu concentration in roots could reach 2794 mg·kg^-1 with Cu concentration of 450 μmol·L^-1 in the solution. The accumulation ability of Cu for different plant tissues followed the sequence of roots > leaves > stems. The chlorophyll concentration in leaves dropped significantly after a slight increase with the increase of Cu concentration in solutions. In addition, the results by SEM-EDAX analysis revealed that Cu mainly distributed in the epidermis, stele and vascular bundle of roots and in the cortex, phloem and xylem of stems. The increase of Cu concentration in culture solution would restrain the accumulation and uptake of Ca²⁺ and Mg²⁺ in roots, stems and leaves, and decrease the concentration of chlorophyll, indirectly influencing the normal photosynthesis process and resulting in obvious decrease of the increase rate of biomass.

• Key words：copper  Salix matsudana Koidz  SEM-EDAX  migration  accumulation

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