Abstract: The flora structure of soil bacteria is an important part of soil ecological environment quality. In order to find out the changes of bacterial flora structure in the rhizosphere soil after continuous cropping of soybean,soybean rhizosphere soil samples of zero- and 2-year of continuous cropping were selected,and their bacterial flora structures were studied using Illumina high-throughput sequencing technique. The results showed that the bacterial abundances and diversity indexes in the rhizosphere soil of zero-year continuous cropping were higher than those of the rhizosphere soil of 2-year continuous cropping. The abundances of these beneficial bacteria Cytophagaceae,Sphingomonas,Bradyrhizobium,and Streptomyces varied insignificantly. Soybean continuous cropping reduced the bacterial diversity of the soil and changed the bacterial flora structure. However,during the short-term continuous cropping process,the variation pattern of rhizosphere microbes in different crops differed,thus it was difficult to infer a common phenomenon resulted from continuous cropping. The results are aimed to provide a theoretical basis for alleviating the short-term soybean continuous cropping obstacle and increasing the yield of soybean.

Key words: continuous cropping, soybean, rhizosphere soil, bacterial flora, Ilumina high-throughput sequencing