干旱胁迫对麻栎幼苗生长及生理生化特性的影响

Effects of water stress on growth and physiological characteristics in Quercus acutissima

为了研究水分胁迫对麻栎幼苗的生长及生理生化特性的影响,以一年生麻栎幼苗为供试材料,试验共设W1、W2、W3、W4 4种水分处理,结果表明:水分胁迫下麻栎幼苗的相对株高生长、相对地径生长、相对冠幅以及生物量增量都随着水分胁迫程度的增加而减少,但是生物量增量在W2、W3、W4处理之间变化并不明显;叶片中游离脯氨酸含量、可溶性糖含量、MDA含量、可溶性蛋白质含量、细胞质膜透性随着土壤水分含量的减少而增大,保护酶SOD、POD、CAT活性先增加,但当土壤含水量达到田间持水量25%(W4处理)时,SOD、POD、CAT活性降低。随着水分胁迫加剧,麻栎幼苗通过增加根冠比以及提高保护酶活性。

To explore the growth,physiological and biochemical characteristics of Quercus acutissima under water stress,one-year-old seedlings of Quercus acutissima were subjected to four levels of soil water stress.Results indicated that the relative growth,relative ground diameter growth,relative crown width and biomass increment of Quercus acutissima seedlings decreased with increase in water stress.However,the biomass increment did not change significantly between W2,W3 and W4 treatments.The content of free proline,soluble sugar,malondialdehyde(MDA),soluble protein and relative lipid membrane permeability in leaves increased with the decrease in soil moisture content.The activities of the protective enzymes superoxide dismutase (SOD),peroxidase (POD)and catalase (CAT) increased at first,but their activities decreased when soil moisture content reached 25% of field capacity.With increase in water stress,seedlings of Quercus acutissima can reduce the damage caused by increasing root-shoot ratio and protective enzyme activity.