干旱条件下锌对玉米根系生长及叶片保护酶活性的影响

Effect of zinc on the growth of maize roots and activity of the protective enzyme of maize leaves under the drought conditions

【目的】探讨锌与作物抗氧化防御系统及抗旱性的关系,揭示锌的抗旱作用机制。【方法】以'陕单308'为供试材料,采用盆栽试验,研究不同水分条件(正常供水、轻度水分胁迫、严重水分胁迫)下,施用锌肥对不同生长期玉米根系生长参数、叶片保护酶活性和丙二醛含量的影响。【结果】严重水分胁迫处理对玉米根系伤害较大,施锌肥可减轻其伤害作用,但难以恢复到作物正常生长状态。在正常供水条件下,施锌可显著提高POD活性,并表现出一定的营养功能;在玉米花期,施锌可提高玉米叶片保护酶POD、SOD和CAT活性,降低丙二醛(MDA)含量,有利于提高水分胁迫下玉米的抗旱性。【结论】除了具有营养功能外,锌还具有提高植物抗旱性的作用,但是该作用是较有限的。

[Objective] The antioxidant defenses and crop stress-resistance by applying zinc （Zn） under drought conditions were investigated to reveal the drought resistance mechanism of zinc. [Method] A pot experiment was conducted to study the effect of zinc on the growth of maiz roots,the protective enzyme activity and the concentration of MDA of maize leaves of different growth stages under the various water supply,the water supply was designed in three rates,namely,adequate water supply,mild water stress,and severe water stress. [Result] The results indicated that, the damage of maize roots was more obviously caused by the severe water stress. Applying Zn fertilizer could decrease the damage, but the crop could not return to the normal. Zn application increased significantly the activity of POD under adequate water supply,and showed nutritional functions. In the key period of blooming,Zn application could increase the enzyme activities of POD, SOD, CAT, and decrease the concentration of MAD, so it is propitious to the drought resistance of maize. [Conclusion] Zn application can not only show nutritional functions, but also play a certain role in drought resistance,but the effect is limited.