Variations of rhizosphere bacterial communities in tea (Camellia sinensis L.) continuous cropping soil by high-throughput pyrosequencing approach

The goal was to investigate the dynamics of soil bacterial community in the chronosequence tea orchards. In this study, soils from tea orchards with continuously cropping histories for 1, 10 and 20 years were collected for investigating rhizosphere bacterial communities using 454 pyrosequencing. The results indicated that Gammaproteobacteria, Alphaproteobacteria, Acidobacteria and Actinobacteria were the main phyla in the tea orchard soils and accounted for more than 60% of the bacterial sequences. At the genus level, the relative abundance of beneficial bacteria, such as Pseudomonas, Rhodanobacter, Bradyrhizobium, Mycobacterium and Sphingomonas, significantly decreased in the 20‐year tea orchard soils. Similar patterns of bacterial community structure were observed between 1‐year and 10‐year tea orchards, which significantly differed from those of 20‐year tea orchards. Redundancy analysis indicated that soil organic carbon and pH showed high correlations (positive or negative) with the majority of the taxa. Long‐term tea cultivation altered the composition and structure of soil bacterial community, which led to the reduction in the beneficial bacteria. The results can provide clues on how to regulate the soil microbial community and maintain the health of soils in tea orchard systems.