Ca^(2+)浸种对酸雨伤害玉米幼苗的影响

Effect of Ca^(2+) pretreatment on the harm of maize seedlings by acid rain

通过砂培实验,研究了钙浸种对酸雨伤害玉米幼苗的防护效应.结果表明,酸雨胁迫下,玉米幼苗叶绿素含量减少,叶绿素a/b比值下降,叶片汁液的pH值降低,SOD-超氧化物歧化酶-活性先升高,而在pH值2.5的酸雨胁迫下转而下降, CAT-过氧化氢酶-活性水平下降,POD-过氧化物酶-活性明显增加,脂质过氧化加剧；而在同一强度酸雨胁迫下,经CaCl2浸种预处理的玉米幼苗叶片细胞汁液pH值较稳定,CAT、SOD的活性水平相对较高,POD活性水平相对较低,叶绿素、蛋白质含量及净光合速率增加,脂质过氧化作用减弱.因此Ca2+浸种对酸雨伤害玉米幼苗有一定的防护作用.

：The protective effect of calcium pretreatment on the harm of maize seedlings by acid rain was studied through sand cultivation experiment.The results showed that under acid rain, the chloraphyll content, the chlorophyll a/b ratio and the pH value of leave cell juice reduced; the activity of superoxide dismutase -SOD- increased first and decreased under the acid rain of pH2.5,that of catalase -CAT- decreased,while that of peroxidase -POD- increased obviously with membrane lipid peroxidation enhanced. However, under the same acid rain coercion, in the maize seedlings pretreated with CaCl2, the chlorophyll content and chlorophyll a/b ratio increased, the pH value of leave cell juice was stable; the activity levels of SOD and CAT increased, and that of POD decreased relatively; the membrane lipid peroxidation decreased, but the contents of chlorophyll and protein and net photosynthesis rate increased. Therefore,the Ca2+ pretreatment could reduce the harmful effect of acid rain on maize seedlings .