Abstract: In order to study the mechanism of drought-resistance in Tamarix leptostachys Bunge, this paper took the seedlings of Tamarix leptostachys Bunge with 2 a panicles as materials, and measured the growth and physiological traits of Tamarix leptostachys Bunge seedlings under different drought stresses. The results showed that: the growth of Tamarix leptostachys Bunge seedlings was inhibited by drought stress, including plant height and ground diameter, and its growth rate  decreased gradually. The relative water content, water potential and chlorophyll a/b content in leaf  gradually decreased with the increase of drought stress, while the relative electrical conductivity, malondialdehyde, proline, soluble protein and soluble sugar in leaves  increased significantly. The activity of superoxide dismutase and peroxidase in leaf of Tamarix leptostachys Bunge seedlings showed an increasing trend, and the activity of catalase first increased and then decreased. To sum up, drought stress had significantly affected activities of protective enzymes and content of osmotic adjustment substances in Tamarix leptostachys Bunge seedlings. So Tamarix leptostachys Bunge could be planted and popularized in dry areas due to high drought resistance.

Key words: Tamarix leptostachys Bunge, drought stress, growth, physiological and biochemical index

摘要： 为探讨细穗柽柳耐旱机制，采用盆栽试验，以2 a生细穗柽柳幼苗为材料，分析了不同干旱胁迫程度对细穗柽柳幼苗生长和生理指标的影响。结果表明：细穗柽柳幼苗生长受干旱胁迫后，植株高度和地径生长速率降低；叶片相对含水率和叶绿素含量随着干旱胁迫程度提高逐渐降低；叶片相对电导率、丙二醛、脯氨酸、可溶性蛋白和可溶性糖含量均呈上升趋势；叶片超氧化物歧化酶和过氧化物酶活性也呈上升趋势，过氧化氢酶活性先增强后下降。综上所述，细穗柽柳幼苗在干旱胁迫下能通过调节自身的酶活性及渗透调节物质含量来缓解干旱胁迫造成的伤害，表现出较强的抗旱能力，适宜在干旱地区种植和推广。

关键词: 细穗柽柳, 干旱胁迫, 生长, 生理生化指标