供锌水平对寒地春玉米幼苗抗氧化酶活性等生理特性的影响

本试验选用不同耐锌玉米品种，采用营养液水培，研究不同锌浓度对玉米株高、地上部干重、根干重及SOD、POD、TTC、硝酸还原酶活性、细胞膜透性的影响。结果表明：耐锌品种‘牡单九’的适宜锌浓度为0．1μmol．L-1，锌敏感品种‘四单十九’的适宜锌浓度为1μmol．L-1。不同锌浓度对玉米生长的影响主要表现在地上部，而对地下部生长影响较小。随着锌浓度的升高，SOD和POD的活性增大。当锌浓度为0．1μmol．L-1时根系活力最高，在锌浓度大于1μmol．L-1时，根系活力下降较明显。硝酸还原酶活性在锌浓度大于0．01μmol．L-1时，随着锌浓度升高而降低。在锌浓度为1μmol．L-1时，细胞膜透性最小，低锌和高锌胁迫下细胞膜透性都有不同程度的增加。

Effects of Zn on the Antioxidant Enzymes Activities and Physiological Charac- teristics in Spring Maize

In order to investigate the effects of different zinc concentrations on physiological characteristics in maize, different Zn-tolerant maize cultivars were used as materials. Plant height, dry weights of root and shoot, root activity, cell membrane permeability, and activities of SOD, POD, TTC and NR were measured. The results showed that the optimal concentration of Zn in maize cultivar ＇Mudan 9＇ and ＇Sidan 19＇ were 0.1μmol.L-1 and 1 1μmol.L-1, respectively. Different Zn concentrations had more effects on aerial part than under- ground part. The activities of SOD and POD increased with the increasing of Zn concentration. The Zn concen- tration of the highest root activity was 0.1 μmol.L-1, and root activity decreased obviously when Zn concentra- tion was more than 1 μmol.L-1. When Zn concentration was more than 0.01 μmol.L-1, NR activity decreased with the increasing of Zn concentration. When Zn concentration was 1 μmol.L-1, cell membrane permeability was lowest. Cell membrane permeability increased under low or high Zn stress.