Replanting disease alters the faunal community composition and diversity in the rhizosphere soil of Radix pseudostellariae

Abstract Replanting disease is a complex system of stressors affecting multiple biological processes, consequently shaping the soil microbial community structure. However, only a few studies have focused on the fauna of the rhizosphere soil. In addition, the effects of replanting disease on the diversity of the faunal community are poorly understood. We collected samples of Radix pseudostellariae rhizosphere soils in different consecutive monoculture fields from three geo-authentic production zones. The microbial abundance and soil faunal community diversity were analyzed using qRT-PCR and 18S rRNA gene sequencing, respectively. Continuous monoculture significantly increased the diversity of the soil nematodes. A total of 14 faunal phyla were detected among all samples, which predominantly included Nematoda, Chordata, Annelida, Arthropoda, Platyhelminthes, Gastrotricha, and Apicomplexa. Compared to the 1-year monoculture, continuous monoculture significantly increased the relative abundances of plant parasites, plant pathogens, phototrophs, and parasites, while significantly reducing the relative abundance of omnivores. Co-occurrence network analysis indicated that continuous monoculture increased the connections and positive correlations of the nematode community. Spearman correlation analysis showed that the soil faunal taxa were significantly associated with various soil factors (pH, sucrase, NO3−-N, NH4+-N, total bacterial, and fungal abundance). Our findings have extended our knowledge regarding the effect of replanting disease on the functional composition of rhizosphere fauna, and the results highlight the role of continuous monoculture in shaping faunal community diversity.