中文摘要：

为了阐明铅胁迫下国槐和紫穗槐对干旱的生理响应机制,进而对比两者在铅胁迫下的抗旱性,为西北矿区耐铅型抗旱植物鉴选提供依据。通过盆栽试验,以1年生的国槐和紫穗槐幼苗为材料,以土壤相对含水量（SRW）100.00%的无铅处理为对照,其余处理外源铅浓度统一设为2 000 mg·kg^（-1）,测定不同水分胁迫强度（土壤相对含水量87.84%,70.00%,52.16%,40.00%）国槐和紫穗槐幼苗叶片中超氧化物歧化酶（SOD）、过氧化物酶（POD）以及过氧化氢酶（CAT）活性的变化。结果表明：单一铅胁迫（2 000 mg·kg^（-1））下国槐和紫穗槐抗氧化酶活性高于对照;铅和干旱复合胁迫下,SRW 87.84%、SRW 70.00%、SRW 52.16%的处理,随着干旱胁迫强度的升高,国槐幼苗叶片SOD、POD和CAT活性均呈先升高后降低趋势且高于对照,紫穗槐SOD和POD活性呈先升高后降低趋势且高于对照,而CAT活性呈先降低后升高趋势;SRW为40%的处理下,国槐的SOD和CAT活性显著低于对照,POD活性略高于对照;紫穗槐SOD、POD和CAT活性均高于对照。铅胁迫（2 000 mg·kg^（-1））对国槐和紫穗槐的抗氧化酶有激活作用;铅胁迫下,紫穗槐对干旱的抗性强于国槐。

英文摘要：

This experiment aims to clarify physiological response mechanism of Sophora japonica and Amorpha fruticosa seedlings to drought under plumbum stress,and provide the basis for selecting the plumbum-resistance and drought-resistant varieties in northwestern mining area. Annual Sophora japonica and Amorpha fruticosa seedlings were selected as test materials. A pot experiment was conducted with five soil relative water content（ SRW） levels,i. e. 100. 00%,87. 84%,70. 00%,52. 16% and 40. 00%,and plumbum concentrations（ 2 000 mg·kg~（-1））,with 100. 00% of SRW without plumbum treatment as control. The activities of superoxide dismutase（ SOD）,catalase（ CAT） and peroxides（ POD） in leaves of annual Sophora japonica and Amorpha fruticosa seedlings were determined. For the single plumbum stress,Sophora japonica and Amorpha fruticosa seedlings＇ antioxidant enzymes activity were significantly higher than those of the control. Under combined stress of drought and plumbum,for the treatments of SRW 87. 84%,SRW 70. 00%,SRW 52. 16%,with the increase in drought stress,the activities of SOD,POD and CAT in leaves of Sophora japonica seedlings initially increased and then decreased,and were higher than those of the control. The same trend was found for Amorpha fruticosa seedlings except for the CAT activity.For the treatment of SRW40%,both activities of SOD and CAT in leaves of Sophora japonica seedlings decreasedwhile the POD activity slightly increased. The activities of SOD,POD and CAT in leaves of Amorpha fruticosa seedlings were higher than those of the control. Plumbum stress（ 2 000 mg·kg~（-1）） promoted the activities of antioxidant enzymes in leaves of Sophora japonica and Amorpha fruticosa seedlings. The drought resistance of Amorpha fruticosa seedlings was stronger than that of Sophora japonica seedlings under plumbum stress.