Diversity patterns of soil microbial communities in the Sophora flavescens rhizosphere in response to continuous monocropping

Abstract

Background : Deterioration in soil continuously cropped with Sophora flavescens (a traditional Chinese herb sensitive to continuous monocropping systems) has not been elucidated, especially regarding taxa present in the microbial community and soil properties. Results : In this study, comparative 16S rRNA and internal transcribed spacer (ITS) MiSeq sequencing analyses were used to examine the taxonomic community structure and microbial diversity in nonrhizosphere soil (CK) and rhizosphere soils (SCC, TCC, and FCC) sampled from fields that had undergone two, three and five years of continuous cropping, respectively. Acidobacteria and Proteobacteria were the most enriched phyla in the bacterial communities, and Ascomycota and Mortierellomycota were the dominant phyla of fungal communities in soil continuously cropped for different periods of time. As the continuous cropping time increased, the diversity of the bacterial community decreased, but that of fungi increased, indicating that long-term monocropping exerted great impacts on microbial community distributions. Redundancy analysis also showed that among the properties of the rhizosphere soil, the available phosphorus, organic matter, total nitrogen and sucrase had the greatest impacts on the diversity of the rhizosphere microbial community. Moreover, a biomarker for S. flavescens soil was also identified using the most differentially abundant bacteria and fungi in soil samples.Conclusions : Overall, investigating the microbial community and physicochemical properties of rhizosphere soil will help clarify the relationship between continuous cropping with S. flavescens and soil degradation. Our study may aid in uncovering the theoretical basis underlying obstacles to continuous cropping and provide better guidance for crop production.

The characters of root-derived fungi from Gentiana scabra Bunge and the relations with their habitats

“…The air-dried and sieved (< 2 mm) soil samples were used to determine the soil physicochemical properties, including pH, available phosphorus (AP) and alkaline hydrolysis of nitrogen (AN). In particular, the soil pH was measured using a pH meter in a soil water suspension ( 1 : 2.5 w/v) after shaking for 30 min (Lei et al 2020). The soil moisture and AN were determined using gravimetric analysis and alkali diffusion methods, respectively (Jia et al 2020;Xu, Du, et al 2021).…”