【毕业论文】铅与酸雨复合污染对大豆植株不同生育期生物量影响论文.doc

PAGE 26 PAGE II 编号 本科生毕业设计(论文) 题目：铅与酸雨对大豆植株 生物量的复合影响 环境与土木工程 学院 环境工程 专业 学 号 1003080114 学生姓名 指导教师 副教授 二〇一二年六月 摘要 摘 要 本文采用水培法研究铅(Pb)与酸雨(AR)对大豆(Glycine max)不同生育期生物量的复合影响。实验结果表明： (1) 单一AR或Pb处理后，幼苗期大豆各生物量指标(叶片面积、单位叶鲜干重、茎鲜干重、根鲜干重)均下降，伤害随pH值降低或Pb浓度增加而增大，具有明显的剂量-效应关系。不同器官对AR或Pb的响应不同，呈现如下规律：根茎叶。AR或Pb对其它生育期(开花结荚期和鼓粒期)大豆的规律与幼苗期相似，降低程度呈现如下规律：幼苗期开花结荚期鼓粒期。90 mg?L-1 Pb对开花结荚期大豆伤害最小。 (2) pH 3.0 AR与Pb复合处理后，幼苗期大豆植株生物量最低，随着生育阶段向后推移，生长减缓，复合污染对大豆生物量的影响逐渐减小，尤其是AR与35mg?L-1Pb复合处理组。pH 3.5与Pb处理后，幼苗期大豆植株，茎、根生物量减少程度低于其它处理组，且其长势较好，而这种优势在其它生育期不明显。pH 4.5与150 mg?L-1 Pb复合处理下，幼苗期大豆自我保护机制失效。与对照相比，鼓粒期大豆植株结荚数明显下降。复合处理组大豆根生物量指标降低程度茎叶。复合处理组大豆生物量降低程度高于单一AR和Pb处理组，鼓粒期差异相对较小。 上述结果可为科学评价突发性AR与Pb污染对不同生育期植物的影响提供理论依据。 关键词：酸雨；铅；生物量；产量；鲜(干)重 Abstract Abstract Abstract ABSTRACT This paper is engaged in an experiment to explore the compound effects of the Lead (Pb) and acid rain (AR) on biomass of water cultured soybean (Glycine max) plants in different growing periods. The results showed that: (1) With the AR or Pb treatment, biomass indexes (leaf area, fresh and dry weight of leaf, stem and root) of soybean seedlings were all decreased, and the lower the pH of AR was or the higher the Pb concentration was, the more serious the damage was. Besides, the response of different organs to the AR or Pb treatment varied, the decrease degree order of biomass was: root stem leaf. It was similar that the damage orders of other growth stages (the beginning pod stage and the beginning seed stage) compared with that of the seedling stage, but the damage degree order was the seedling stagethe beginning pod stagethe beginning seed stage. In addition, during the beginning pod stage, the damage of 90 mg·L-1 Pb treatment was the lowest. (2) In the pH3.0 + Pb groups, the biomass of soybean seedlings was lowest; as the soybean plants grew up, the growth rate of the soybean became slower, leading to the less effects of the