Changes of microbial community in the rhizosphere soil of Atractylodes macrocephala when encountering replant disease

Abstract

Consecutive replanting significantly affects the yield and quality of Atractylodes macrocephala due to replant disease. To explore the changes in the rhizosphere soil when atractylodes get replant disease, we detect soil physicochemical properties and the microbial community. The results show higher level of pH and phosphatase activity in the rhizo-soil of diseased plants than that of healthy ones. Moreover, 42 species of bacteria in the phylum of Acidobacteria, Gemmatimonadetes, Nitrospirae, Elusimicrobia, and Chlorobi show higher diversity, while 8 species in the phylum of Actinobacteria, Bacteroidetes, Firmicutes, and Fibrobacteres demonstrate lower diversity in that of diseased ones. In particular, decreased numbers of some beneficial bacteria including Sphingobium and Hyphomicrobium while increased numbers of pathogens such as Asticcacaulis, Rhizomicrobium in diseased ones may lead to replant disease. For fungi, there are 10 species with lower diversity in diseased ones, which belong to Ascomycota and Glomeromycota. In conclusion, microecological imbalance in Atractylodes rhizosphere caused by variation of the soil microbial community is considered the primary cause of replant disease. Some bacteria such as Sphingobium and some fungi including Alternaria alternate are closely related to the replant disease.