盐旱交叉胁迫对小麦种子萌发及幼苗保护酶活性的影响

Effects of Salt and Drought Cross Stress on Seed Germination and Protective Enzyme Activity of Wheat Seedling

以商麦5226为材料,采用不同浓度PEG-6000溶液和不同浓度Na Cl溶液模拟不同程度的干旱胁迫及盐胁迫,研究盐旱交叉胁迫下小麦胚芽鞘长度、发芽势、发芽率和小麦幼苗保护酶活性随胁迫时间的变化规律。结果表明:在不同浓度盐旱交叉处理下,随着胁迫时间的延长,胚芽鞘相对伸长速率(RER)整体呈下降趋势,超氧化物歧化酶(SOD)、过氧化物酶(POD)活性先上升再下降,过氧化氢酶(CAT)活性先下降后上升;随盐旱交叉胁迫浓度增加,胚芽鞘长度、发芽势和发芽率呈下降趋势,SOD、POD和CAT活性先上升后下降。分析认为小麦幼苗在盐旱交叉胁迫下表现出交叉适应性,适度的盐旱胁迫能增加小麦的抗逆能力。

Wheat variety Shangmai 5226 was used as experimental material,different concentrations of PEG-6000 solution and Na Cl solution were used to simulate different degrees of drought stress and salt stress respectively,and the coleoptile length,germination potential and germination rate of wheat seeds,as well as the protective enzyme activity of wheat seedlings under salt and drought cross stress were studied. The results showed that：under different degrees of salt and drought cross stress,along with the extension of stress time,the relative elongation rate of seed coleoptile was decreased in general,and the activity of superoxide dismutase（SOD） and peroxidase（POD） increased first and then decreased,while the activity of catalase（CAT） decreased first and then increased. When the concentration of PEG-6000 and Na Cl solution increased,the coleoptile length,germination potential and germination rate revealed a decreasing trend,while the activity of SOD,POD and CAT increased at first and then decreased. We think that wheat seedlings have a cross adaptation to salt and drought cross stress,and moderate salt and drought stress can increase the adversity resistance of wheat.