巨菌草抗旱性能及重金属镉污染修复特性研究

发布时间：2018-04-08 11:42

本文选题：巨菌草　切入点：镉胁迫　出处：《四川农业大学》2015年硕士论文

【摘要】：植物的正常生长发育常受到自然界的诸多环境因子的影响,如低温、干旱、洪涝等此外在我国工农业的迅速发展的背景下,人类的频繁活动导致生态环境日益恶化,以土壤重金属污染为首的生态环境问题严重影响植株的生长繁殖。本研究以巨菌草(Puelia sinese Roxb)为研究对象,采用盆栽控制实验的方式,利用控水和控制重金属的实验方法,设计了对照(75%田间持水量(FC))、干旱(25% FC)、重金属镉(3 mg/kg)及其交互作用(25% FC 3mg/kg)四个处理。研究了干旱和重金属镉对巨菌草生长、气体交换、光合色素、生理生化、养分特征、Cd积累与分配的影响。主要研究结果如下：干旱、镉胁迫及其交互作用都引起了植株的膜脂过氧化,增加了植株活性氧的积累,影响植株的正常生长,从而降低其生物量。在干旱条件下,植株的气体交换速率和净光合速率显著降低,这使植株能更好利用有限的水资源,植株过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性显著升高,表明其清除活性氧的能力增强,从而阻止膜脂过氧化,达到保护细胞的目的,植株的耐性系数达到0.72,这些都表明巨菌草具有较强的抗干旱的性能；在镉胁迫下,植株改变了其生长特征,类胡萝卜素、脯氨酸以及CAT活性显著升高,以适应镉胁迫,植株的耐性系数达到0.72,表明巨菌草具有较强的耐镉能力；在交互作用下,镉和干旱交互作用打破了植株活性氧平衡,植株CAT、POD、抗坏血酸过氧化物酶(APX)活性的增加,表明植株为应对交互作用,出现活性氧的积累,各种抗氧化物酶活性增加,从而维持植株细胞内活性氧平衡,因而巨菌草营养生长和生物量的积累有一定程度的下降,但与单一的干旱、重金属胁迫相比,植株的生物量并无显著下降,说明干旱和镉的交互作用对巨菌草的生物量无显著叠加效应；植株的耐性系数达到0.74,表明巨菌草在交互胁迫下也能够正常生长。巨菌草植株对镉的抽提效果而言,无干旱胁迫下的植株对镉的抽提总量高于干旱胁迫下的植株,单一重金属处理的巨菌草地上部分镉含量为5.41 mg/kg;交互处理巨菌草地上部分镉含量为4.60 mg/kg,按巨菌草平均鲜草产量为213,900 kg/hm2,干物质产量约150,000 kg/hm2推算,巨菌草在镉胁迫下可以抽提镉0.82 kg/hm2,在交互胁迫下可以抽提镉0.69 kg/hm2,根据巨菌草较强的抗旱性能和对重金属镉的耐性和修复特性,该物种在干旱区域的生态恢复重建和镉污染土壤修复方面具有较高的应用价值可以用于干旱条件中的农业生产以及污染环境治理。
[Abstract]:Effects of many environmental factors, often by nature, the normal growth and development of plants such as low temperature, drought, floods and other in the rapid development of industry and agriculture in China under the background of frequent human activities lead to the deteriorating ecological environment, the ecological environment problems in heavy metal contaminated soil by seriously affected plant growth and reproduction in this study. Jujun grass (Puelia Sinese Roxb) as the research object, by pot experiment, using the experimental method of water control and control of heavy metals, the design of the control (75% field capacity (FC)), drought (25% FC), cadmium (3 mg/kg) and their interactions (25% FC 3mg/kg) four treatment study on the drought and heavy metal cadmium. The growth of giant JUNCAO gas exchange, photosynthetic pigment, physiological and biochemical characteristics, nutrient accumulation and distribution, effect of Cd. The main results are as follows: drought, and their interactions are caused by cadmium stress The membrane lipid peroxidation of plant, plant increased the accumulation of ROS, affecting the normal growth of the plant, thereby reducing the biomass. Under drought conditions, the plant gas exchange rate and net photosynthetic rate decreased significantly, the plant can make better use of limited water resources, plant peroxidase (POD), superoxide dismutase (SOD), catalase (CAT) activity increased significantly, that enhance the ability of scavenging active oxygen, thereby preventing lipid peroxidation, protect cells, plant tolerance coefficient reached 0.72, which shows that the performance of giant JUNCAO has strong resistance to drought stress in cadmium; next, the plant changed its growth characteristics, carotenoids, proline and CAT activity increased significantly, to cadmium stress, plant tolerance coefficient reached 0.72, showed that Jujun grass has strong resistance to cadmium stress; the interaction of cadmium, and drought over The interaction has broken the balance of active oxygen plant, CAT plant, POD, ascorbate peroxidase (APX) activity increased, showed that in response to the interaction, appear the accumulation of active oxygen and increase the activity of antioxidant enzymes, so as to maintain the balance of active oxygen in plant cells, thus Jujun grass vegetative growth and biomass accumulation a certain degree of decline, but with a single drought, heavy metal stress, no plant biomass decreased significantly, indicating the biomass of drought and cadmium interaction on giant JUNCAO no significant additive effect; plant tolerance coefficient reached 0.74, also showed that Jujun grass can grow normally in the interaction under the stress of cadmium extraction effect. Jujun grass plants, no amount of extraction of cadmium under drought stress was higher than that of plants under drought stress, the giant bacteria on the grassland of single heavy metal cadmium content was 5.41 mg/kg Interactive processing; giant grass bacteria cadmium content was 4.60 mg/kg, according to the average Jujun grass grass yield of 213900 kg/hm2, the dry matter yield of about 150000 kg/hm2 projections, Jujun grass under cadmium stress can extract 0.82 kg/hm2 CD, under the stress of cadmium in interaction can extract 0.69 kg/hm2, according to the drought resistance and the strong Jujun grass cadmium tolerance and repair characteristics, this species has higher application value and cadmium pollution remediation of soil ecological restoration in arid region can be used in drought conditions in agricultural production and environmental pollution control.

【学位授予单位】：四川农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X173;X53

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