【作者】 张春荣；

【导师】 夏立江；

【作者基本信息】 中国农业大学 ， 环境工程， 2004， 硕士

【摘要】 本论文是在我国水资源危机日趋严重，土壤重金属镉污染面积不断扩大的情况下，针对抗旱、抗寒能力强，生物量大、经济实用价值高的紫花苜蓿，进行的重金属镉、锌的抗性试验研究。结果表明：在试验浓度范围内，镉、锌对紫花苜蓿的种子萌发的影响呈剂量关系。通过种子的发芽指数和活力指数的计算数据可知，低浓度的镉、锌可促进种子萌发和幼苗生长，高浓度时则有抑制效应。盆栽试验中镉对紫花苜蓿的出苗率、根、茎的生物量的影响与种子的萌发呈现同一规律；镉在紫花苜蓿体内的含量也与土壤中镉浓度有关：低浓度0—6mg／kg时，紫花苜蓿根部的镉含量低于茎、叶中的镉含量，但己超出我国饲料卫生标准2倍，浓度大于10mg/kg时，根部的镉含量比饲料卫生标准高出20倍，而土壤中镉含量大大降低，所以此时的紫花苜蓿是修复镉污染土壤的较好的植物；当加200mg／kg锌后，镉的毒害作用明显减小，随着生长时间的增长，生物量受镉的影响也在减小，同时紫花苜蓿体内的镉含量大幅度降低，有些己降到饲料标准以下。镉对紫花苜蓿叶中的叶绿素、类胡萝卜素含量的影响则是随着镉浓度的增加而减小。 由于环境条件的不同，镉对微区中紫花苜蓿的影响远小于对盆栽的影响。更多还原

【Abstract】 In our country, water crisis is increasingly serious and the pollution eara of soil heavy metal Cadmium expands continuously. Under this situation, my dissertation studys alfalfa which has good economic value and strong drought and cold resistance. In the study, resistance experiments of heavy metal- Cadmium arid Znic are carried out. It proved that in the scope of experimental concentration the effect which Znic and Cadmium has on alfalfa presents dosage relation. It is known that low concentration of Cadmium and Znic can promote seeds to sprout and seedling to grow; high concentration has restrain effect. In the potted plant experiment, Cadmium has the same effect on sprout rate, root and leave of seedling and seed of alfalfa. The content of Cadmium in the body of alfalfa has relation with the concentration of Cadmium. When the concentration is low, 0-6 mg/kg , the content of Cadmium in the root of alfalfa is lower than in the stern and leaf, but two times higher than the forage hugiene standard of our country. When the concentration is higher than 10mg/kg, the content of Cadmium in the root is 20 times higher than the standard, but the content of Cadmium in the soil decreased obviously, so alfalfa of this condition is the best alternative for renovating polluted soil. When 200mg/kg Znic is added, the poison of Cadmium is decreased dramatically with the grow time increasing, the Cadmium effect on living number decreased. At the same time, the content of Cadmium in the body of alfalfa has decreased, some of them has decreased under standard. The content of chlorophyll and carotenoid in alfalfa decrease when the concentration of Cadmium increased.The effect which Cadmium has on alfalfa of mini-eara is smaller than potted plant because condition is difference.更多还原