I8S
Genomic DNA was extracted from 0.25 g fresh soils with a PowerSoil DNA Isolation Kit (MoBio Laboratories, Inc., Carlsbad, CA, USA) following the manufacturers instruction. An approximately 334 bp region of the 18S rDNA gene was amplified with two-step PCR. Briefly, the extracted DNA was diluted 10 times and amplified with GeoA-2 (Schwarzott and Schler 2001) / AML2 (Lee et al., 2008), and NS31 (Simon et al., 1992) / AMDGR (Lumini et al., 2010). The primer NS31 was modified with a unique 12 nt barcode at the 5end. The final PCR products from all samples were mixed and then subjected to Illumina Miseq platform at Environmental Genome Platform of Chengdu Institute of Biology, Chinese Academy of Sciences.