目录
摘要Ⅱ
关键词Ⅱ
AbstractⅢ
引言
引言（或绪论）1
1(材料与方法1
1.1(实验材料 1
1.1.1(实验菌株1
1.1.2(培养基选用2
1.2□实验方法 2
1.2.1□外生菌根真菌As(V)耐性菌株的筛选2
1.2.1.1 (菌种活化2
1.2.1.2□耐As(V)菌株的筛选2
1.2.1.3□As(V)耐性菌株生长曲线的绘制及同源性分析2
1.2.1.4□As(V)耐性菌株形态观察2
1.2.1.5□数据处理2
1.2.2□外生菌根真菌对As(V)耐性的生理机制研究2
1.2.2.1(菌种活化2
1.2.2.2(As(V)处理下菌株生物量的测定2
1.2.2.3(As(V)处理下培养基中pH、Eh及As形态的测定3
1.2.2.4(As(V)、As(Ⅲ)处理下培养基中As形态的连续变化测定3
1.2.2.5(数据处理3
2□结果与分析3
2.1□As(V)耐性菌株的筛选4
2.1.1□As(V)耐性菌株的固体培养基筛选4
2.1.2□As(V)耐性菌株生长曲线和系统发育树4
2.1.3□菌丝透射电镜观察5
2.2□外生菌根真菌对As(V)耐性机理研究6
2.2.1□As(V)对Hv菌株生物量的影响6
2.2.2□As(V)对培养基pH、Eh的影响7
2.2.3□As(V)对培养基中As形态的影响7
3□讨论 8
3.1□As(V)耐性菌株的筛选8
3.2□外生菌根真菌对As(V)耐性机理研究8
3．3□ 外生共生真菌应用前景9
致谢9
参考文献9

外生菌根真菌对砷的耐性及其机理研究
摘 要
外生菌根(Ectomycorrhiza，ECM)是由外生菌根真菌(Ec *51今日免费论文网|www.51jrft.com +Q: &351916072& 
tomycorrhizal fungi，EMF)与高等植物根系之间形成的一种互惠共生体，它可以增强植物根系对水分及矿质营养的吸收，提高植物的抗逆性。外生菌根真菌与植物联合修复可能是未来极具发展潜力的重金属污染处理方法。本文选用了实验室保存的外生菌根真菌菌种，Hebeloma vinosophyllum (Hv)、Hebeloma crustuliniforme (He)、Tylopilus felleus (Tf)等作为研究材料，通过比较它们在不同浓度的As(V)胁迫下的生长情况，筛选出As(V)耐性菌株，并进一步通过真菌生长曲线以及同源性分析，筛选出Hv这一外生菌根真菌为As(V)耐性菌株。为了探究Hv对As(V)耐性及其耐性机理，采用液体培养基培养实验探究了处于不同砷浓度胁迫下的生物量和液体培养基的pH和Eh变化，发现高浓度As胁迫下，Hv生长受到抑制或延迟；培养基的pH的变化没有受到砷浓度的明显影响，无论高浓度或低浓度，基本都随着培养时间的增长而增大，而Eh则随之变小。测定培养基中砷不同形态含量发现，Hv的液体培养基中发现了显著的As(V)的还原过程——As(V)含量减少以及As(Ⅲ)含量增加。因此我们可以认为Hebeloma vinosophyllum (Hv)是砷的耐性菌并且Hv对As(V)的还原是使其具有砷耐性的主要机理。
STUDY ON THE TOLERANCE OF EXOGENOUS MYCORRHIZAL FUNGI TO ARSENIC AND ITS MECHANISM
ABSTRACT
Ectomycorrhiza (ECM) is a reciprocal symbiosis formed between Ectomycorrhizal fungi (Ectomycorrhizal fungi, EMF) and the roots of higher plants. It can enhance the absorption of water and mineral nutrients by plant roots and improve plant stress resistance.The combined remediation of ectomycorrhizal fungi and plants may be a promising method for the treatment of heavy metal pollution in the future.This article chooses the ectotrophic mycorrhiza fungi strains preserved in our laboratory, Hebeloma vinosophyllum (Hv), Hebeloma crustuliniforme (He), Tylopilus felleus (Tf) and so on As the research material, by comparing them under the stress of different concentration of As (V), the growth situation, selected the As (V) patience strains, and further through the fungal growth curve and homology analysis, selecting and Hv a ectotrophic mycorrhiza fungi for the As (V) patience strains.In order to explore the tolerance of Hv to As(V) and its mechanism, the changes of biomass and pH and Eh of the liquid medium under the stress of different arsenic concentrations were investigated by the liquid medium culture experiment. It was found that under the stress of high concentration of As, the growth of Hv was inhibited or delayed.The pH of the medium was not significantly affected by the concentration of arsenic. No matter the concentration of arsenic was high or low, it basically increased with the growth of culture time, while Eh decreased accordingly.Determination of arsenic content of different form found in culture medium, Hv liquid medium found significant reduction process of As (V), the As (V) content reduced and As(Ⅲ)content increased.Therefore, we can think that Hebeloma vinosophyllum (Hv) is a bacterium with arsenic tolerance and the reduction of As(V) by Hv is the main mechanism to make it have arsenic tolerance.

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