| 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. |
