Abstract: This study firstly researched germination characteristics of Halogeton glomeratus under different concentrations of heavy metals Cu²⁺,Zn²⁺,Ni²⁺,Cd²⁺ and Pb²⁺ supplemented with 100 mmol·L^-1 NaCl. The results showed that germination rate and germination potential increased at first and then decreased with the increase of the heavy metals concentrations. It indicated that the low concentration of heavy metal ions promoted the germination of plants. Fresh weight,dry weight and seedlings height decreased gradually. The results of ion contents showed that Cd²⁺ and Pb²⁺ contents increased at first and then decreased,and Cu²⁺,Zn²⁺ and Ni²⁺ contents increased with increasing heavy metals concentrations. The root activity of Cu²⁺ and Zn²⁺ increased first and then decreased,and it decreased with the increase of Ni²⁺,Cd²⁺ and Pb²⁺ concentrations. The comprehensive clustering and principal component analysis were carried out to obtain the critical concentrations of Cu²⁺,Zn²⁺,Ni²⁺,Cd²⁺ and Pb²⁺ in Halogeton glomeratus,which were 1.00 mmol·L^-1,10.00 mmol·L^-1,0.30 mmol·L^-1,0.20 mmol·L^-1 and 0.50 mmol·L^-1,respectively. The most important indexes were germination index,dry weight,germination energy,dry weight and germination energy when the stress concentration reached the critical value for Halogeton glomeratus.

Key words: Heavymetals, Stress, Halogeton glomeratus, Germination

摘要： 本研究首次以盐生草（Halogeton glomeratus）为材料，模拟盐胁迫（100 mmol·L^-1 NaCl）环境，探讨不同浓度重金属Cu²⁺，Zn²⁺，Ni²⁺，Cd²⁺，Pb²⁺处理对其萌发特性的影响。结果表明：随处理浓度的升高，发芽率和发芽势均表现为先升高后下降趋势，表明低浓度重金属离子可促进植物的萌发，幼苗鲜重、干重、株高均呈现逐渐下降趋势。测定离子含量得出，Cd²⁺和Pb²⁺离子含量随着胁迫加重呈先升高后下降的趋势，Cu²⁺，Zn²⁺和Ni²⁺离子含量逐渐增加。测定根系活力发现，Cu²⁺，Zn²⁺根系活力随浓度的升高呈先上升后下降趋势，Ni²⁺，Cd²⁺，Pb²⁺根系活力逐渐降低。综合聚类及主成分分析得出：盐生草耐Cu²⁺，Zn²⁺，Ni²⁺，Cd²⁺，Pb²⁺的临界浓度分别为：1.00 mmol·L^-1，10.00 mmol·L^-1，0.30 mmol·L^-1，0.20 mmol·L^-1和0.50 mmol·L^-1，在胁迫浓度达临界值时贡献率最大的指标分别为：萌发指标、干重、发芽势、干重和发芽势。

关键词: 重金属, 胁迫, 盐生草, 萌发