Objective   Chemical and microbial factors in field soils related to disease occurrence of continuously cropped Pesudostellaria heterophylla were investigated.

  Method  Microbial community structure and diversity of rhizosphere soil from 5 continuous cropping P. heterophylla fields in Zherong County, Fujian were analyzed on data obtained by high-throughput sequencing technology. Correlation analysis of the microbial distribution was conducted based on the chemical properties of rhizosphere soil and phenolic acids.

  Result  A clustering analysis on 744,331 fungal and 1,032,029 bacterial effective sequences resulted in 1,314 operational taxonomic units for the fungi and 10,310 for the bacteria. At each of the 5 locations, the number of common OTUs was significantly greater than that of unique ones. On the other hand, the alpha diversity analysis showed significant differences in microbial composition and abundance among the habitats as the species richness at Habitat Ⅳ, Ⅱ, and Ⅰ were higher than those at Habitat Ⅴ and Ⅲ. The canonical correspondence analysis indicated the soil chemical properties and phenolic acids in the root exudates significantly affected the microbial distribution. Fusarium and other pathogenic fungi were found at all 5 sites with the count of the pathogenic fungi inversely proportional to that of other microbial species, i.e., a possible correlation between Fusarium and the rhizosphere community.

  Conclusion  It appeared that the continuous cropping that frequent fungal diseases on the plants might be significantly associated with the evolution of rhizosphere microbial structure and diversity mediated by the root exudate from P. heterophylla itself.