Fungal communities associated with Yucatan tropical forest soil chronosequence at Kaxil Kiuic Biocultural Reserve
Genomic DNA from each sample was extracted using DNeasy PowerLyzer PowerSoil PowerSoil Kit (Qiagen, Valencia CA, USA) according to the manufacturer's instructions with the following modifications: 0.5 g of sample instead of 0.25 g was used and incubation periods at 4C were increased from 5 to 20 min. The ITS2 rRNA gene region of the DNA extracts was amplified with a polymerase chain reaction, using the KAPA HiFi Hotstart polymerase (Roche, Indianapolis, IN, USA) with the 5.8S and ITS4 primers (Taylor et al., 2016) already tagged with Illumina sequencing adaptors. Each PCR ran for 30 cycles, with an annealing temperature of 55C. Samples went through a second round of PCR to add barcodes for HTS. Amplicons were cleaned, normalized using SequalPrep kits, and pooled.  In addition to all samples, we included 2 negative extraction controls, and a positive control consisting of a synthetic ITS mock community of 9 fungal species (Palmer et al., 2018).