干旱胁迫对黄土高原4种乡土禾草保护酶活性及膜系统的影响

摘要

The growth development, strategy of water using and drought-resistance mechanism of four native gramineous grass(Stipa bungeana , Bothriochloa ischaemum , Cleistogenes songorica and Agro-pyron cristatum) in Loess plateau were studied by pot culture experiments simulating different soil water status in Yangling of China. The different levels of soil-water-treatments were set by artificially controlling soil moisture. This paper mainly studied the time and space changes of protective enzymes activities. The result showed that the effects of protective enzymes activities were different on four species under different water contents. The mass fraction of O2 ~ and the molality of MDA increased under drought stress. With the extending of water stress, the activity of four species enzymes, such as SOD, POD, CAT, APX in the leaves of the four species were up-down fluctuating. At the early and middle water stress stages, they may boost up the protective enzymes activities to protect the en-dosmosis from damaging. As the protective enzymes activities weaker at the following stage, they may adopt the strategy of improving osmotic adjustment substances content to adapt drought. In summary, all parameters showed that A. Cristatum and B. Ischaemum had stronger drought-resistance a-bility than S. Bungeana and C. Songorica and also had stronger accommodation ability.%对黄土高原的长芒草(Stipa bungeana)、白羊草(Bothriochloa ischaemum)、无芒隐子草(Cleistogenes songorica)和冰草(Agropyron cristatum)4个乡土禾草采用盆栽模拟干旱处理,测定不同水分胁迫下保护酶活性,结果表明:4个草种在开始遭受干旱胁迫时,均造成(MDA)质量摩尔浓度增加,O2-的积累,SOD、POD、CAT和APX活性上下波动；在胁迫前期和中期,主要以增强保护酶活性来有效地清除活性氧,抑制膜脂过氧化.4个禾本科牧草都具有一定的抗旱性,随干旱时间持续延长其适应性增强,冰草和白羊草的抗旱性大于无芒隐子草和长芒草.