水曲柳苗木不同根序对干旱胁迫的生理生化反应  

Physiological and Biochemical Responses of Different Order roots in Fraxinus mandshurica Seedlings to Drought Stress

作　　者：卫星[1] 王政权[1] 张国珍[1] 陈海波[1] 王婧[1] 

机构地区：[1]东北林业大学林学院,哈尔滨150040

出　　处：《林业科学》2009年第6期16-21,共6页Scientia Silvae Sinicae

基　　金：黑龙江省自然科学基金项目(C200627);黑龙江省青年科学技术技术基金项目(QC06C005);东北林业大学校科研项目(05001)

摘　　要：以1年生水曲柳苗木为试材,在温室土基盆栽,测定干旱胁迫后苗木1级根和2级根细根活力、膜透性、可溶性蛋白含量和抗氧化物酶系(POD、SOD、CAT)活性的变化。结果表明:在干旱胁迫过程中,1,2级根均发生活力下降、膜透性增加、可溶性蛋白含量减少的现象,且1级根变化程度大于2级根。在干旱胁迫过程中1,2级根SOD活性均先上升后下降,CAT和POD活性虽然在胁迫后期(40天)显著高于对照,但与胁迫初期相比(15,30天)也呈显著下降趋势,对照变化不显著。抗氧化酶系还原活性氧分子的能力逐渐减弱,膜质过氧化程度加重,导致细胞膜透性升高,活力下降(r2=0.45～0.58)。与2级根相比,1级根对干旱胁迫的生理生化反应更明显。The physiological and biochemical responses of fine roots of Fraxinus mandshurica seedlings under drought stress were investigated. Under drought stress, vigor of fine roots with first or second order, membrane permeability, contents of soluble proteins, and activities of antioxidant enzymes （POD, SOD, and CAT） were examined. The results showed that both root vigor and soluble protein content decreased significantly and membrane permeability increased significantly by drought exposure in first and second order roots. The first order root changed more than the second order one. During the drought exposure, the activities of SOD increased at the beginning and then decreased at the severe drought stress. CAT and POD in fine roots of seedlings exposed to drought still 40 days further decreased significantly compared with 15 days and 30 days＇ exposure, however their activities were the control higher than that in which had little variation. The results suggested that the abilities of antioxidant enzymes to scavenge the reactive oxygen species were weakened, resulting in an increase in lipid peroxidation and ion leakage, and a decrease in root vigor （r^2 = 0.45 - 0.58）. It was included that compared with the second order fine roots, the first order fine roots had more physiological and biochemical responses to drought stress.

关 键 词：水曲柳 细根 根序 干旱胁迫 

分 类 号：S718.43[农业科学—林学]