水分胁迫对苹果属植物抗氧化酶活性的影响研究

试验研究水分胁迫对 3种苹果属植物湖北海棠、西府海棠和新疆海棠根系和叶片抗氧化酶活性的影响结果表明 ,随水分胁迫的加重 ,3种海棠抗氧化酶活性逐渐增强 ,当土壤绝对含水量降至 6 .5 %时 ,过氧化氢酶 (CAT)活性首先达高峰 ,而超氧化物歧化酶 (SOD)活性高峰则出现于土壤绝对含水量为 2 .8%时 ,之后 2种酶活性逐渐降低 ,复水后又均有所升高 ;过氧化物酶 (POD)活性高峰出现于土壤绝对含水量为 3.2 %时 ,之后逐渐下降 ,至复水后仍呈下降趋势 ;丙二醛 (MDA)含量随水分胁迫的加重而逐渐增加 ,当土壤绝对含水量降至 1 .8%时其含量最高 ,复水后则呈下降趋势。种间抗氧化能力耐旱型新疆海棠 >西府海棠 >干旱敏感型湖北海棠

Effects of water stress on the activities of antioxidant enzymes of Malus L.plant

The changes in activities of SOD, CAT, POD and MDA contents in leaves and roots of three different species of Malus L. were studied under the water stress. The results show that the activities of SOD, CAT and POD are gradually increased under the water stress conditions. CAT activity firstly reaches the highest point when the absolute water content of soil decreases to 6.5%, but the highest point of SOD activity is at 2.8%, then their activities are decreased with further increasing of water stress, and are partly recovered by rewatering. The highest point of POD activity appears when the absolute water content of soil declines to 3.2%, declines again with further increase of water stress and still decreases after rewatering. MDA content is gradually increased under the water stress conditions, and arrives at the highest point when the absolute water content of soil declines to 1.8% and decreases after rewatering. It is concluded that the order of antioxidization abilities of the species is M.sieverii>M micromalus>M.hupehensis.