镉胁迫对玉米生理特性的影响

采用砂培试验．用不同浓度Cd^2 对玉米幼苗进行处理．对处理后玉米的生理特性进行了研究。结果表明：镉对玉米的毒害受到时间和浓度双重因子的控制．在低浓度镉处理下．玉米的叶绿素含量和过氧化物酶活性首先稍升高．可以认为这是植物的一种自我保护性机制在起抗胁迫作用；但随着Cd^2 处理浓度的增大，叶绿素含量和根系活力降低．脯氨酸含量增加．这表明玉米对低浓度Cd^2 有一定的抵抗能力．但在高浓度处理下则受到损害；玉米不适合作为镉污染的环境监测植物．但游离脯氨酸变化明显．因此脯氨酸可以作为植物对镉污染的监测指标。

Effects of Cd intimidation on physiological characteristics of maize

In this paper, sand-culture medium was used to investigate the physiological and ecological response of maize to cadcium pollution stress .The results show that the toxicity of Cd~(2+) on maize is controlled by time and concentration of Cd~(2+). The indexes of Chlorophyll contents and Peroxide enzyme increased firstly in lower concentration of Cd~(2+), which may be regarded as a protecting function of plants. With the cumulating of Cd~(2+), the chlorophyll valuesd and the activity of root decreased and the free proline increased.It indicates that the resistance of maize against lower concentration of Cd~(2+) is slightly higher, while the cells would have been harmed at the great amount of Cd~(2+).Maize is not suit to be the environmental supervising plant for the heavy metal Cd. While the indexes of dissociate proline is changed obviously,it can be the monitoring index of heavy metal pollution.