摘要
为了测定不同浓度PEG干旱胁迫下沙冬青幼苗的膜透性、丙二醛含量、可溶性蛋白含量、SOD、POD、CAT三种酶的酶活性及游离脯氨酸含量的变化,本试验设5种不同浓度的PEG干旱胁迫处理,测定沙冬青幼苗的相关生理指标。结果表明:随着PEG浓度的增加,(1)沙冬青幼苗的生长与胁迫程度呈负相关,随PEG浓度增加,幼苗逐渐矮小枯黄,死亡率增大;(2)沙冬青幼苗的相对电导率、丙二醛含量持续上升;(3)可溶性蛋白和脯氨酸的含量呈现先上升后下降趋势;(4)超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)的酶活性均表现出先上升后下降的趋势。幼苗在10%PEG胁迫下,POD和CAT酶活性最高,15%PEG时SOD酶活性最高。从实验结果可以看出,低浓度(5%-15%)PEG胁迫下,沙冬青幼苗表现出较强的抗旱性,可以通过自身调节维持正常生长,当PEG浓度增至20%以上时,其生长受到严重影响。
The Ammopiptanthus mongolicus seedlings, under 5 different concentrations of PEG drought stress treatments, physiological indexes such as： membrane permeability, MDA content, soluble protein content, the enzyme activity of SOD,POD,CAT and the change of free proline content were measured and analyzed. The results showed that ： with the increasing of PEG concentration, （ 1 ） there was a significant negative correlation between the Ammopiptanthus mongolicus seedlings and the stress degree, the seedlings dwarfed and scorched gradually and increased mortality with an increase in PEG concentration; （2）The relative electrical conductivity and MDA content of the seedlings kept elevating; （3）The content of soluble protein and free pro- line increased firstly and then decreased; （4） SOD.POD,CAT enzyme activity increased firstly and then decreased. The enzyme activity of POD,CAT was the highest under 10% PEG stress, while the SOD was the highest in 15% PEG. All the results show that, under the low concentration （5 % - 15% ） PEG the seedlings had more drought resistance and could maintain normal growth by auto regulation, while the growth of the seedlings was badly influenced whenthe PEG concentration increased to more than 20%.
出处
《青海农林科技》
2015年第4期25-30,共6页
Science and Technology of Qinghai Agriculture and Forestry
关键词
PEG胁迫
沙冬青幼苗
生理特性
PEG stress
Ammopiptanthus Mongolicus
Seedlings
Physiological characteristics
