锌对玉米幼苗生长和细胞保护酶活性的影响

用不同浓度的锌(Zn^2 )处理玉米种子，研究对幼苗生长和细胞保护酶活性的影响．结果表明，当Zn^2 浓度高于50mg／L时，幼苗的生长受到明显抑制．根系长度、根体积和株高随Zn^2 浓度的增加而降低；根系和土地上部生物量在Zn^2 浓度为5mg／L时达到峰值，而后随Zn^2 浓度的增加，植株干重减少．随Zn^2 浓度的增加，幼苗根系活力和叶片硝酸还原酶活性下降，叶绿素含量减少，根内丙二醛(MDA)含量增加；抗坏血酸氧化酶(ACO)和多酚氧化酶(POL)活性下降，过氧化物酶(POD)活性增大,过氧化氢酶(CAT)活性在Zn^2 浓度为5mg／L时显著高于对照，随Zn^2 浓度的增加，活性降低。

The Effects of Zn Pollution on Seedling Growth and Cell Protective Enzyme Activity of the Maize

The maize was cultured in the solution with different concentrations of zinc (Zn~(2+)) to investigate the effects of zinc on seedling growth and cell protective enzyme activity of the maize. The result showed that when the concentration of Zn~(2+)solution was above 50 mg/L, the seedling growth of the maize was checked. With the increased concentration of Zn~(2+) solution, the root length, root volume and seedling height would be reduced. The dry matter weight of would rise up to the highest at 5 mg/L of Zn~(2+) culture concentration and then decrease afterwards. The vigor of roots, the activity of nitrate reductase in leaves and the content of chlorophylls of the maize seedling would be reduced. As the content of MDA in roots was increased, the activity of ACO and POL would be decreased. As the activity of POD was increased, the activity of CAT would be higher than the contrast at 5 mg/L of Zn~(2+)concentration and then decreased afterwards.