Astragalus-cultivated soil was a suitable bed soil for nurturing Angelica sinensis seedlings from the rhizosphere...

Angelica sinensis (Oliv.) Diels is an important Chinese medicinal plant. A. sinensis seedlings are grown on an undisturbed alpine meadow soil to ensure the high-quality seedlings, but these soils are disappearing year after year. Thus, selecting a suitable bed soil for A. sinensis seedlings could ensure their long-term sustainability. Using HiSeq sequencing of 16S and 18S marker genes, we investigated the rhizosphere bacterial and fungal microbiotas of the seedlings grown in wheat, astragalus, potato, and angelica-cultivated soils at a geo-authentic habitat. Co-occurrence network analysis, canonical correspondence analysis, Mantel test, and Envfit test were used to examine the relationship between the microbiotas and the surrounding factors. Astragalus-cultivated soils exhibited the following properties: the highest plant weight, the highest neighborhood connectivity in the bacterial network, the highest ratio of positive/negative relationship in both bacterial and fungal networks, the highest relative abundance of the arbuscular mycorrhizal fungi and the ectomycorrhizal fungi, the lowest relative abundance of Rhizoctonia solani, the suitable soil pH, and the close relationship between the rhizosphere microbiotas and the ecological factors. Moreover, each growth stage has its own major drivers in all crop-cultivated soils. Climate temperature and soil pH at 56 days after planting, precipitation at 98 days, and plant weight as well as microbial biomass C and N at 129 days were the major drivers of the bacterial and fungal microbiotas. Overall, the astragalus-cultivated soil was a suitable bed soil for nurturing A. sinensis seedlings to replace the undisturbed alpine meadow soils.