腐植酸钾浸种对干旱胁迫下玉米幼苗保护酶活性及MDA含量的影响

探索腐植酸钾浸种对玉米抗旱性的影响及其在作物生长化学调控中的作用。采用不同浓度（0、300、400、500 μg/mL）的腐植酸钾浸种玉米，研究了在16%的PEG-6000模拟干旱胁迫环境下，三叶期玉米幼苗叶保护酶活性及丙二醛含量的变化。与对照相比，浸种玉米的超氧化物歧化酶活性增高，但无显著差异；浸种玉米的过氧化物酶活性增高，在500 μg/mL时达极显著水平；浸种玉米的过氧化氢酶活性增高，在400、500 μg/mL时分别达极显著水平和显著水平；浸种玉米的丙二醛含量降低，在300~400 μg/mL时达显著水平，在500 μg/mL时达极显著水平。腐植酸钾浸种玉米，可减轻玉米在干旱胁迫下的膜脂过氧化程度，提高玉米抗旱性。

Effects of Soaking with Potassium Humate on the activity of Protective Enzymes and the Level of MDA of Maize Seedlings under Drought Stress

Research on the effects of soaking maize seeds with potassium humate against drought and the effects of potassium humate in chemical regulation of crop growth.They are used to soak maize seeds with different concentrations of potassium humate （0,300,400,500 μg/mL）,and then study the change of activity of protection enzymes as well as the level of MDA of maize seedling under the imitation drought stress with 16% PEG-6000.Comparing with the contrast,the superoxide dismutase （SOD） activity of maize seedling which seeds were soaked with potassium humate increased,but the difference was no significant.The peroxidase （POD） activity increased and reached an extremely significant level in 500 μ g/mL.The catalase （CAT） activity increased and reached an extremely significant level in 400 μg/mL and a significant level in 500 μ g/mL.The level of malondialdehyde （MDA） decreased and reached a significant level in 300-400 μ g/mL and an extremely significant level in 500 μ g/mL.Soaking maize seeds with potassium humate,which might be reduced the level of membrane lipid peroxidation of maize seedling under drought stress and improve their ability against drought.