采用桶栽称量法,对重度干旱、中度干旱和适宜水分也分别为田间最大持水量的35%、55% 和75% (CK)页条件下达乌里胡枝子[Lespedeza daurica (Laxm.) Schindl.]和铁杆蒿(Artemisia sacrorum Ledeb.)叶片的7 个生理生化指标的动态变化进行研究。结果表明:在干旱条件下,随处理时间延长,达乌里胡枝子和铁杆蒿叶片的SOD 活性逐渐增加,总体上与对照差异不明显;二者的POD 活性呈先升高后降低的变化趋势、CAT 活性总体上呈降低-升高-降低的变化趋势、APX 活性则呈现不同的波动规律,但POD、CAT 和APX 活性峰值及出现的时间有差异,其中在重度干旱条件下POD、CAT 和APX 活性的变化幅度均最大。在干旱条件下,达乌里胡枝子和铁杆蒿叶片MDA 含量均随处理时间延长呈先升高后降低的趋势且MDA 峰值均明显低于对照,但二者的MDA 含量水平及其峰值出现的时间有一定的差异;在不同处理条件下,二者叶片的游离脯氨酸含量随处理时间延长呈现不同的波动规律,其中,在中度干旱条件下游离脯氨酸含量变化幅度均最大;在干旱条件下,二者可溶性蛋白质含量均随处理时间延长逐渐增加,但总体上与对照差异不显著。研究结果说明:达乌里胡枝子和铁杆蒿对干旱胁迫的生理响应有一定差异,但作为黄土高原乡土植物,二者具有相似的抗旱机制,表现出较强的抵御和适应干旱的能力。

The dynamic changes of seven physiological-biochemical indexes in leaves of Lespedeza daurica (Laxm.) Schindl. and Artemisia sacrorum Ledeb. under heavy and moderate drought and suitable soil moisture conditions [35%, 55% and 75% (CK) of the maximum moisture content in soil, respectively]were researched by bucket weighing method. The results show that under drought stress conditions, with prolonging of stress time, SOD activity in leaves of L. daurica and A. sacrorum all increases gradually and has no obvious difference with that of control; POD activity of two species appears the trend of firstly increasing and then decreasing, their CAT activity  appears the trend of decreasing-increasing-decreasing in general and their APX activity appears the different fluctuation patterns, but there are differences in the peak value and its appearance time of POD, CAT and APX activities, in which change range of POD, CAT and APX activities all are the largest under the heavy drought condition. Under drought stress conditions, with  prolonging of stress time, MDA content in leaves of L. daurica and A. sacrorum appears the trend of firstly increasing and then decreasing and MDA peak value all is lower than that of the control, but there is a certain difference in the content and the peak appearance time of MDA between two species. Under different stress conditions, free proline content of two species appears the different fluctuation patterns with prolonging of stress time, in which, the change range of free proline content is the largest under moderate drought stress. Under drought stress conditions, soluble protein content of two species all increases gradually with prolonging of stress time but has no obvious difference with that of the control in general. It is suggested that there is a certain difference in physiological response to drought stress between L. daurica and A. sacrorum, but as native plant in Loess plateau, two species possess the similar mechanism of drought resistance and appear the stronger ability of resisting and adapting to drought stress.