镉胁迫对玉米生理特性的影响

Effects of Cd stress on the physiological characteristics of maize

试验研究不同浓度Cd胁迫对玉米生理特性的影响结果表明,玉米耐受性好,Cd胁迫下生长发育正常,0.2mg/L、0.5mg/L和1.0mg/L低浓度Cd处理玉米叶片叶绿素含量和过氧化物酶活性略升高,其最大应激浓度为1.0mg/LCd、毒性浓度为5.0mg/LCd;但随胁迫时间延长或胁迫浓度加大,玉米叶片叶绿素含量连续降低,根系活力降低后回复,而脯氨酸含量明显升高又回落,玉米表现出对低浓度Cd有一定抵抗能力,且Cd对玉米的毒害受时间和浓度双重因子的制约。玉米植株体内游离脯氨酸变化明显,因此脯氨酸可作为某些植物对重金属离子的同期抗逆性指标。

The effects of Cd stress on the physiological characteristics of maize were studied. The results show that when maize grows normally, the resistance of maize against Cd is strong. The indexes of chlorophyll content and peroxide enzyme increase firstly at 0.2mg/L, 0.5mg/L, 1.0mg/L of Cd. The maximum stimulating concentration of Cd is 1.0mg/L and the toxicity concentration is 5.0mg/L. With the prolong of time and accumulation of Cd, the chlorophyll content decreases gradually, the activity of root falls and resumes, and the free proline increases and drops, indicating that the resistance of maize is strong and the poisons of Cd is restricted by the factors of time and its concentration. The dissociate proline changes obviously, it may be as a guide line of some plants against heavy metal.