水分胁迫下四翅滨藜和绵毛优若藜保护酶活性变化

Variation of protective enzyme activity of Atriplex canescens and Ceratoides lanata under water stress

在水分胁迫下,对四翅滨藜Atriplex canescens和绵毛优若藜Ceratoides lanata2个耐旱牧草叶内的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和丙二醛(MDA)含量进行测定,试验结果表明:随着水分胁迫的增强,四翅滨藜体内的SOD和CAT活性表现为上升趋势,而绵毛优若藜体内的SOD和CAT活性呈现降低趋势;MDA含量在四翅滨藜和绵毛优若藜体内随着水分胁迫的加剧都增加了,但相对而言,四翅滨藜体内的MDA含量相对低于绵毛优若藜。由于四翅滨藜体内的SOD和CAT活性随着时间的推移而升高,使MDA含量远少于绵毛优若藜,从而能更好免遭O2-的伤害,提高了植物体的抗旱机制。在研究期间,四翅滨藜的成活率为98.35%,而绵毛优若藜的成活率仅为61.20%,表明前者的抗旱能力远高于后者。因此,研究结果可为筛选适合西北干旱荒漠地区牧草的引种和繁育工作提供基础依据。

SOD, CAT and MDA of Atriplex canescens and Ceratoides lanata were measured under water stress. The results indicated that the activity of SOD and CAT of A. canescens increased under wa- ter-stress, but decreased in C. lanata. MDA contents of both species increased with the increasing stress, but A. canescens had higher MDA than C. lanata. The increase of SOD and CAT activity＇with prolonged stress in A. canescens reduced its MDA content, which prevented the plant from O2^- harm and increased its drought resistance and gave 98.35% survival rate, while C. lanata only had 61.20% viability. The result could be used as reference to selecting adapted forage species to dry desert region in northwest.