重金属胁迫下毛竹幼苗生理响应及其吸收规律研究

发布时间：2018-06-05 12:49

本文选题：重金属 + 植物修复　；参考：《浙江农林大学》2015年硕士论文

【摘要】：现在许多国家的土壤和水资源受到了重金属的污染,而这一问题严重影响环境和人类的健康。本文以毛竹为供试材料,采用水培和土培的方法,系统地对毛竹重金属吸收类型、重金属胁迫下的生理及形态响应、修复的机理和应用等方面,进行了初步的探讨,取得的主要研究结果如下:1.以毛竹种子为供试材料,研究四种重金属(Pb2+、Zn2+、Cu2+、Cd2+)胁迫对毛竹种子萌发的影响。结果表明:(1)Pb2+和Cd2+对毛竹种子的发芽率、发芽势、发芽指数及活力指数有抑制作用,低浓度下Cu2+和Zn2+对毛竹种子的发芽势、发芽率、发芽指数等指标有促进作用,高浓度则显著抑制;当浓度达到1600μmol L-1时Cd2+对种子萌发的抑制效果明显强于其他三种元素;(2)选取根尖数、根表面积、根体积、根系总长四个根系形态指标发现,低浓度处理下Pb2+、Zn2+对根系生长有促进作用,而Cu2+和Cd2+起到明显的抑制作用;(3)处理10d后,种子萌发幼苗地上部对Pb2+、Zn2+、Cu2+、Cd2+的含量最高可达6810.51、1387.77、951.77、429.33 mg kg-1,转移系数Zn2+Cd2+Pb2+Cu2+。2.通过水培实验研究了毛竹对重金属铅、锌、铜、镉的生理反应、吸收特点和细胞内部结构的变化。铜和镉处理下,毛竹的生物量都出现了随着重金属处理浓度的增大生物量依次降低的大致趋势。铅和锌处理下,毛竹的生物量在低浓度处理下并未出现显著性差异,随后生物量才出现降低的趋势。不同的重金属对毛竹的细胞组织尤其是细胞器的损害程度是不一致的。毛竹在叶片细胞组织尤其是细胞器膜等方面受损,导致其在光合作用、新陈代谢减缓,抑制毛竹的生长。3.通过土培实验研究了重金属铅、锌、铜、镉对毛竹生长的影响、吸收转移重金属的能力和修复土壤重金属的潜力。毛竹对铅和锌比对铜和镉具有更高的耐性,生长更为繁盛,具有更茁壮的茎和肥厚深绿的叶片。在铅、锌和铜处理的污染土壤上,毛竹的生物量都是先增加后减小的;在镉的污染土壤上则是生物量持续下降的。毛竹对于重金属的吸收转运,锌和镉大于铅和铜。同时,毛竹虽然不是超积累植物,但是毛竹具备独特的生物性能、繁殖能力、以及适应性强,使其在重金属污染土壤的修复上具有巨大的潜力。
[Abstract]:Nowadays, soil and water resources in many countries are polluted by heavy metals, which seriously affects the environment and human health. In this paper, using Phyllostachys pubescens as the test material, the methods of water culture and soil culture were used to systematically discuss the types of heavy metal absorption, physiological and morphological responses under heavy metal stress, repair mechanism and application of Phyllostachys pubescens. The main findings are as follows: 1. The effects of four heavy metals (Pb _ 2 ~ (2 +) Zn _ (2) O _ (2) Cu _ (2) O _ (2) CD _ (2) on the germination of Phyllostachys pubescens seeds were studied. The results showed that Pb2 and Cd2 could inhibit germination rate, germination potential, germination index and vigor index of Phyllostachys pubescens seeds, and Cu2 and Zn2 could promote germination potential, germination rate and germination index of Phyllostachys pubescens seeds at low concentration. When the concentration reached 1600 渭 mol L-1, the inhibitory effect of Cd2 on seed germination was significantly stronger than that of the other three elements, such as root tip number, root surface area, root volume and total root length. Under low concentration, Pb2 Zn 2 could promote root growth, while Cu2 and Cd2 had obvious inhibitory effect on root growth for 10 days. After 10 days treatment, the highest content of Pb2 Zn 2 Cu 2 O 2 CD 2 in shoot of seed germinating seedlings could reach 6810.51C 1387.7795 1.7N 429.33 mg kg-1, and the transfer coefficient Zn2 Cd2 Pb2 Cu2 路2 was up to 6 810.51mg / kg ~ (-1), and the transfer coefficient of Zn ~ (2 +) was 429.33 mg / kg ~ (-1). The physiological responses of Phyllostachys pubescens to heavy metal lead, zinc, copper and cadmium were studied by hydroponics. Under Cu and CD treatments, the biomass of Phyllostachys pubescens decreased with the increase of heavy metal concentration. There was no significant difference in biomass of Phyllostachys pubescens under lead and zinc treatments under low concentration treatment, but then the biomass of Phyllostachys pubescens decreased. The degree of damage of different heavy metals to cell tissues, especially organelles, of Phyllostachys pubescens was different. Phyllostachys pubescens were damaged in cell tissue, especially organelle membrane, which resulted in the decrease of photosynthesis and metabolism, and the inhibition of growth of Phyllostachys pubescens. The effects of lead, zinc, copper and cadmium on the growth of Phyllostachys pubescens were studied through soil culture experiments. Phyllostachys pubescens have higher tolerance to lead and zinc than copper and cadmium, more prosperous growth, stronger stems and thicker dark green leaves. The biomass of Phyllostachys pubescens increased first and then decreased in the polluted soils treated with Pb, Zn and Cu, but decreased continuously in the polluted soils of cadmium. The absorption and transport of heavy metals in Phyllostachys pubescens were higher in Zn and CD than in Pb and Cu. At the same time, Phyllostachys pubescens is not a super accumulative plant, but it has unique biological properties, reproductive ability and strong adaptability, which makes it have great potential in remediation of heavy metal contaminated soil.
【学位授予单位】：浙江农林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S795.7;X53;X173

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