干旱胁迫下草地早熟禾幼苗几种抗旱性指标的变化

The Change of Several Drought Resistance Indexes for Poa pratensis's Seedling under Drought Stress

测定了干旱胁迫下冷季型草坪草草地早熟禾幼苗几种抗旱性指标。结果表明:在干旱胁迫期间,早熟禾幼苗植株体内过氧化物酶活性、脯氨酸含量均先升后降,与对照相比较,差异显著(P<0.05);当土壤含水量大于17.9%时,MDA的含量均高于对照,但没有显著差异(P>0.05),当土壤含水量小于17.9%时,MDA的含量显著上升,与对照相比较,差异极显著(P<0.01),表明膜结构遭到破坏,抗逆性显著下降,为草地早熟禾幼苗抗旱的临界值。

Several drought resistance indexes of Pos pratensis's seedling are determined under drought stress.The result showed that the Peroxidase activity and the praline content are first all increased and reduced later during the drought stress.Compared with CK,the differences(P<0.05)is significant.As the water content of soil is more than 17.9%,the content of MDA is higher than CK.the differences(P<0.05)is not notable.As the water content of soil is less than 17.9%,the content of MDA is increasing obviously.Compared with CK,the differences(P<0.01)is very notable.For Pos pratensis's seedling,the increased content of MDA was showed that its membrane structures destroyed and the resistance was reduced.17.9% is a critical content of the soil water to tolerate drought stress.