Continuous monocropping can affect the physicochemical and biological characteristics of cultivated soil. Sophora flavescens is a valuable herbal medicine and sensitive to continuous monocropping. Currently, diversity patterns of soil microbial communities in soil continuous monocropping with S. flavescens have not been extensively elucidated. In this study, comparative 16S rDNA 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 monocropping, respectively. Among the microbial communities, a decreased abundance of Acidobacteria and increased abundances of Proteobacteria and Bacteroidetes were found with the increase in monocropping years of S. flavescens. As the continuous monocropping time increased, the diversity of the bacterial community decreased, but that of fungi increased. 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. Our study indicates that long-term monocropping exerted great impacts on microbial community distributions and soil physicochemical properties. The relationship between microbial community and physicochemical properties of rhizosphere soil would help clarify the side effects of continuous S. flavescens monocropping. Our study may aid in uncovering the theoretical basis underlying obstacles to continuous monocropping and provide better guidance for crop production.

中文翻译：

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苦参根际土壤微生物群落多样性模式响应连续单作。

连续单作会影响耕地土壤的理化和生物学特性。苦参是一种珍贵的草药，对连续单作敏感。目前，苦参连续单作土壤微生物群落的多样性模式尚未得到广泛阐明。在这项研究中，比较 16S rDNA 和内部转录间隔 (ITS) MiSeq 测序分析用于检查非根际土壤 (CK) 和根际土壤 (SCC、TCC 和 FCC) 中的分类群落结构和微生物多样性分别经历了两年、三年和五年的连续单作。在微生物群落中，随着 S. flavescens 单作年数的增加，发现酸杆菌的丰度减少，变形菌和拟杆菌的丰度增加。随着连续单作时间的增加，细菌群落的多样性下降，而真菌群落的多样性增加。冗余分析还表明，在根际土壤性质中，有效磷、有机质、全氮和蔗糖酶对根际微生物群落多样性的影响最大。此外，还使用土壤样品中差异最大的细菌和真菌鉴定了苦参土壤的生物标志物。我们的研究表明，长期单作对微生物群落分布和土壤理化性质有很大影响。微生物群落与根际土壤理化性质之间的关系将有助于阐明连续单作苦参的副作用。我们的研究可能有助于揭示连续单作障碍的理论基础，并为作物生产提供更好的指导。