Abstract: The paper aims to explore the Physiological adaptation mechanism of wild Elymus nutans to Cu²⁺ and Zn²⁺ stress in Baqing County,Tibet. The experiment took wild Elymus nutans from Baqing County as materials,and studied the effects of different concentrations of Cu²⁺ and Zn²⁺ on seed germination and seedling growth by paper germination method. The results were as follows:300 mg·L^-1 Cu²⁺ and 500 mg·L^-1 Zn²⁺ treatment significantly inhibited seed germination and seedling growth of wild Elymus nutans in Baqing County,Tibet. Low concentration of Zn²⁺ (200 mg·L^-1) promoted seed germination;Under low concentration of Cu²⁺(20 mg·L^-1) and Zn²⁺(200 mg·L^-1) stress,the root length of seeds was slightly longer than that of the control. With the increase of Cu²⁺ and Zn²⁺ concentration,the content of chlorophyll in leaves of Elymus nutans seedlings decreased,while the relative conductivity and Malondialdehyde content increased. It can be seen that wild Elymus nutans in Baqing County,Tibet,has a low tolerance for Cu²⁺ stress,but has certain tolerance to Zn²⁺ stress,and has strong application potential in vegetation restoration of Zn²⁺ contaminated soil in central Tibet.

Key words: Elymus nutans, Domestication, Cu²⁺, Zn²⁺, Cell membrane damage

摘要： 为探索西藏巴青县野生垂穗披碱草（Elymus nutans）对Cu²⁺，Zn²⁺胁迫的生理适应机理，本试验以巴青县地区的野生垂穗披碱草为材料，采用纸上发芽法，研究了不同浓度Cu²⁺和Zn²⁺胁迫对其种子萌发和幼苗生长的影响。结果表明：300 mg·L^-1Cu²⁺和500 mg·L^-1 Zn²⁺处理下，垂穗披碱草种子萌发及幼苗生长受到显著抑制（P<0.05）；而低浓度的Zn²⁺（200 mg·L^-1）处理促进了种子萌发；20 mg·L^-1的Cu²⁺和200 mg·L^-1Zn²⁺处理下，种子根长略高长于对照；随着Cu²⁺和Zn²⁺胁迫浓度的增大，幼苗叶片叶绿素含量表现为下降趋势，相对电导率和丙二醛含量呈现上升趋势。由此可知，垂穗披碱草对Cu²⁺的耐受性较差，但具有一定的耐Zn²⁺胁迫能力，在西藏中部Zn²⁺污染土壤的植被修复中具有较强的应用潜力。

关键词: 垂穗披碱草, 驯化, Cu²⁺, Zn²⁺, 细胞膜损伤