【作者】 刘发来；

【导师】 王瑞刚； 冯福应；

【作者基本信息】 内蒙古农业大学 ， 生物化学与分子生物学， 2010， 硕士

【摘要】 根际微生物作为土壤生态系统的生物组成部分,是陆地生态系统中重要的生命体,对所生存的微环境十分敏感。现在,土壤微生物指标已被公认是土壤生态系统变化的预警及敏感指标。本文以内蒙古浑善达克沙地和毛乌素沙地主要植物根际土壤为研究对象,通过直接法提取沙蒿,锦鸡,黄柳等植物根际土壤的微生物总DNA,采用建立土壤细菌16S rDNA克隆文库的方法,对不同季节,不同沙地的不同植物根际微生物菌群进行比对研究,分析微生物群落结构的时空尺度变化,获取变化的作用因子,为研究和利用细菌与土壤环境间的相互作用提供理论依据,最终为治理土壤荒漠化提供理论依据。研究结果表明:在植物生命活动不旺盛的11月,在植物根际土壤中,一般都是Pseudomonas为优势菌;到了4月和8月植物生命活动旺盛的时期,Rhizobiales和Sphingomonadales这两类与植物生长关系密切的菌得到了大量聚集,成为这两个时期的优势菌;研究还发现,同一地点不同植物的根际土壤中主要优势菌相同,非优势菌存在较大变化;不同地点的相同植物的根际土壤微生物主要优势菌基本相同,只是一些非优势菌存在变化。总之,植物根际的主要细菌类群与随季节而变化的植物的代谢活动有密切关系。更多还原

【Abstract】 As biological components of ecosystems, rhizosphere soil bacteria are important organisms in terrestrial ecosystems, and they are very sensitive to micro-environment, their populations may be greatly affected by changes in environmental conditions. Now, soil bacteria has been recognized as an sensitive early warning indicator of soil ecosystem change.This paper selected the rhizosphere soil of main plants in Hunshandake and Mu Us Sandland of Inner Mongolia as studying object, by direct extracted the total microorganism DNA of artemisia, caragana, yellow willow and other plants rhizosphere soil. Throμgh establishing the clone library of 16S rDNA of bacteria in soil, compared different seasons and different Desert’s different plants rhizosphere microflora, analyze bacterial community structural changes in spatial and temporal scales, to obtain the factors leading to the changes, for the study and use of The interaction between bacteria and the soil environment provide a theoretical basis, ultimately, for control of soil desertification, provide a theoretical basis.The results showed that: In the plant life activities are not strong in November, in the rhizosphere soil, generally Pseudomonas is the dominant bacteria; to April and August, at this time plants have strong life activities, Rhizobiales and Sphingomonadales these two groups of bacteria to which the plant growth are chosely related gathered in these two periods became the most dominant of bacteria; the study also found that different species of plants rhizosphere soil bacteria of the same location, whose dominant bacteria are same, but there is a big changement in the non-dominant bacteria; the same plant rhizosphere bacteria at different locations, whose main advantaged bacteria is basically the same, but some non-dominant bacteria have some changements. In short, the main rhizosphere bacterial populations is closely related to metabolic activity of the plant which is changed with the seasons.更多还原