2.5 Microbial community structure analysis
Total soil microbial DNA was extracted from 0.5 g fresh soil. DNA SPIN extraction kit (Felix Bio-Tech, USA). The fungal ITS1 region was amplified using the following primers: ITS1F: (5’-TCCGTAGTGAACCTG-3’), ITS2-Rev: (5’-GCTGCGTTCTTCATCGATGC-3’). In the present study, soil samples were sent to Shanghai Personal Biotechnology Co., Ltd. for high-throughput sequencing.