It meaned that simulated acid rain made the toxic effects of zn or cd on growth of the plants more serious . the fresh weights and chlorophyll contents of phaseolus vulgaris l were the highest when ph value of acid rain was 4 . 5 , zn concentration was 60 mg / kg , and or cd concentration was 0 . 5 mg / kg . this showed that lower acidity of simulated acid rain and lower concentrations of zn or cd could promote growth of the plants 本试验中，酸雨加zn或者酸雨加cd使小白菜鲜重小于单一污染处理，说明酸雨增加了zn 、 cd对小白菜的毒害作用；而当酸雨ph值为4 . 5 、 zn浓度为20mg / kg或cd浓度为0 . 5mg / kg时，四季豆鲜重达到最大值，这表明低强度的酸雨和低浓度的zn 、 cd促进四季豆的生长。
In this dissertation , effects of different acidities of simulated acid rain and different concentrations of zn or cd on the fresh weights , contents of chlorophyll , activities of sod , pod , cat , and contents of mda in brassica chinensis l and phaseolus vulgaris l were studied with a pot experiment . the main results were as follows : the contents of chlorophyll of brassica chinensis l and phaseolus vulgaris l had the same tendency as the biomass of these two plants treated with simulated acid rain , zn and cd . the fresh weights and contents of chlorophyll of brassica chinensis l decreased with increasing in concentrations of zn , cd and acidity of simulated acid rain 本文通过盆栽试验，研究了不同强度的模拟酸雨和不同浓度的zn 、 cd对小白菜、四季豆生长量、叶绿素含量、根和叶保护酶活性以及mda含量的影响，主要研究结果如下：在模拟酸雨和zn 、 cd的胁迫下，小白菜、四季豆叶绿素含量与其生长量有着相同的变化趋势，其中小白菜鲜重和叶绿素含量随着zn 、 cd浓度以及酸雨强度的增加而减小，四季豆鲜重和叶绿素含量随着zn 、 cd浓度以及酸雨强度的增加先升高后下降。
Toxic effects of high acidity of acid rain and high concentrations of zn or cd on growth of brassica chinensis l and phaseolus vulgaris l were obvious , which was showed in the fact that the leaves were smaller and narrower than the contrast , and the growth of the plants were inhibited 强酸性降雨和土壤高浓度的zn 、 cd污染对小白菜和四季豆生长产生毒害作用，主要表现在叶片变窄变薄，失绿现象明显，植株矮化，生长发育受阻。小白菜、四季豆根、叶中mda含量与zn 、 cd浓度呈正相关。
