摘要:重金属污染对作物具有明显的毒害作用,是影响农产品质量安全的重要因素。重金属污染能导致土壤肥力降低,使农作物产量降低和品质下降。现在有很多研究机构对此现象越来越重视此现象并开始着手研究重金属对农作物的胁迫作用。本项目拟通过对镉污染土壤种植的335种玉米籽粒的金属元素的含量分析入手,研究不同品种间镉,铬,铅,镍,铜积累量的差异,得到籽粒镉高积累 (335个品种前5%)玉米品种15种,籽粒镉低积累的 (335个品种后5%)玉米品种15种。综合分析表明籽粒镉高积累的玉米品种其重金属元素Cr,Pb等重金属含量也较高,营养元素Cu含量较低;籽粒镉低积累的玉米品种其重金属元素Cr,Pb等重金属含量也较低,营养元素Cu含量较高;而不论这30个玉米品种籽粒中镉积累量高低,其中的营养元素Ni无明显差异。本研究可为筛选玉米籽粒重金属差异积累的材料提供重要参考。50238
毕业论文关键词:玉米;镉;重金属;积累;测定
Analyzing the contents of heavy metals in Maize grains
Abstract:Heavy metal has obvious harmful effects on plants,it is the main influeatial factor on quality security of agriculture products. It can not only decrease soil fertility,but also decrease yield and quality of crops.Now there are a lot of research institution paying attention to this phenomenon and researching the stress effect of heavy metal towards agriculture products. This project is based on 335 kinds of corn planted in cadmium contaminated soil.The accumulation of heavy metal elements Cd, Cr, Pb, Ni and Cu in the grain in different varieties is analysed. The results showed that there are 15 kinds of maize with high cadmium accumulation in grain(335 varieties, the first 5%)and 15 kinds of maize with low cadmium accumulation in grain (335 varieties, the last 5%). Comprehensive analysis showed that the accumilation of heavy metals such as Cr and Pb in maize with high cadmium accumulation in grain is high , and the accumilation of nutrient element Cu is low.And it also shows that the accumilation of heavy metals such as Cr and Pb in maize with high cadmium accumulation in grain is low , and the accumilation of nutrient element Cu is low.Meanwhile, no matter the amount of Cd accumulation in the grain of these 30 maize varieties, there is no significant accumilation difference between the nutrient elements Ni. This study can provide important reference for screening the differential accumulation of heavy metals in maize grain.
Key words: maize; cadmium; heavy metal; accmulation;determination
目 录
摘要1
关键词1
Abstract1
Key words1
引言1
1 材料与方法4
1.1 技术路线 4
1.2.1植物材料4
1.2.2实验试剂4
1.3实验仪器4
1.4实验方案4
1.4.1获取植物材料(玉米籽粒)4
1.4.2 玉米籽粒消解测镉浓度4
2结果与分析5
2.1 确定籽粒镉积累玉米品种和高镉积累玉米品种5
2.2 玉米镉元素及其他金属元素含量分析5
3讨论9
3.1对玉米耐镉性与其对重金属富集积累转运机制的讨论9
3.1.1 玉米籽粒中镉含量的积累可能与铬、铅的积累有协同作用9
3.1.2玉米籽粒中镉含量的积累与铜的积累有拮抗作用9
3.2后续试验方向9
致谢9
参考文献10
玉米籽粒重金属含量分析
重金属污染已成为当今社会的热点话题。工业生产中“三废”(废水、废气和废渣)的排放和农业中农药化肥的大量施用是土壤重金属的主要来源。砷(As)、镉(Cd)是我国污染面积较大的两种重(类)金属,在很多地区(如湖南某地、广东韶关等)均已严重超标,这严重影响了农作物的生长和食品安全。砷(As)是最早发现的致癌化学物质之一,美国环境保护署把它排在了所有有害物质首位[1; 2],它能引起肺癌等多种癌症,早在1879年,就有大量矿工因吸入了含有砷的气体而导致肺癌的惨剧发生[2; 3]。镉(Cd)在土壤中的迁移率很高,即使在低浓度的水平下也会对植物、动物、微生物等产生危害。过量的镉毒害可能导致植物组织细胞产生活性氧,改变活性氧代谢有关酶的活性,引起膜脂过氧化,增加细胞膜的透性,从而抑制植物生长[2]。砷和镉以多种方式危害人类健康,其可通过生物富集和食物链来施展毒害效应。植物对砷和镉的吸收、运输和解毒机制以及农作物中砷和镉对人体的健康风险等问题在最近几十年引起了国内外学者的高度重视,因此研究植物对重金属的吸收和耐性极为重要。