镉胁迫对玉米光合特性的影响

在模拟光条件下，通过盆栽试验研究了外源镉胁迫对盆栽玉米光合特性的影响。结果表明，高浓度镉（100 mg·kg^-1）胁迫下玉米叶片叶绿素a、b及总叶绿素c含量明显减少，分别比对照CK下降了65.32%、54.95%、62.57%。镉浓度1、5、15、50 mg·kg^-1处理下叶片的叶绿素含量下降得少，Cha/Chb的比值降低较少。镉浓度15、50、100 mg·kg^-1胁迫下导致玉米叶片光合速率下降，光补偿点提高，光饱和点和表观量子效率降低，暗呼吸速率升高，较低浓度镉胁迫（1、5 mg·kg^-1）则提高光补偿点、光饱和点和表观量子效率，降低暗呼吸速率。

Influence of Cadmium Stress on Photosynthetic Characteristics of Maize

The pot experiment was conducted to study the effects of added cadmium （Cd）on photosynthetic characteristics of maize under simulated photosynthetic radiation（PAR ）. The results showed that in the high concentration of Cd（ 100 mg·kg^-1 ）stress, corn leaf blade chlorophyll a, b and the total chlorophyll c content obvious reduction, the distinction ratio compared CK to drop 65.32%, 54.95%, 62.57%. The concentration Cd（ 1, 5, 15, 50 mg·kg^-1） under processing leaf blade＇s chlorophyll content dropped little, the Cha/Chb ratio reduced few. The concentration Cd（ 15, 50, 100 mg·kg^-1） forces caused the corn leaf blade photosynthesis speed to drop, the light compensation point enhanced, the light saturation point and the apparent quantum efficiency reduced, the dark respiratory rate elevated, the low concentration cadmium coercion（ 1, 5 mg·kg^-1） enhanced the light compensation point, the light saturation point and the apparent quantum efficiency, cut the dark respiratory rate.