title: Amplicon of poplar bulk soil
design: Two primer pairs (799F/1392R, 799F/1193R) (Zhang et al., 2019) were used for bacterial 16S rRNA V5-V7 region amplification by a nested PCR. The primer pairs ITS3F/ITS4R (Bellemain et al., 2010) were used to amplify the ITS2 region of fungal ITS gene. PCR products were checked on a 2.0% agarose gel and purified with the AxyPrep DNA Gel Extraction Kit (Axygen Biosciences, Union City, CA, USA). All products were pooled in equimolar concentration and then sequenced on the Illumina MiSeq PE355 platform (Illumina, San Diego, CA, USA) with a pair-end protocol by Majorbio Bio-Pharm Technology Co., Ltd. (Shanghai, China).