design: Sequencing libraries were prepared for the fungal ITS2 region, targeted with the 4R and 86F primers (De Beeck et al., 2014). The first PCR was performed with the above-mentioned specific primers flanking Illumina overhang adapters sequences in a 25L PCR reaction containing 2x KAPA HiFi HotStart ReadyMix (Kapa Biosystems Inc, USA), 1M of each primer and 2.5L of DNA. The first PCR was carried out under the following conditions: initial denaturation at 95C for 3min, followed by 25 cycles of 95C for 30 s, 54C for 30 s and 72C for 30 s, and a final extension step at 72C  for 5 min. The second PCR was conducted with the Nextera XT index kit (Illumina, San Diego, CA) following manufacturer's instructions. Amplicons were verified on 1% agarose gel and purified using AMPure XP magnetic beads (Beckman Coulter, USA). Concentrated samples and negative controls were pooled in equimolar ratios, diluted to 4 nM and sequenced with a 2 x 250 run on an Illumina MiSeq platform at Teagasc Next Generation DNA sequencing facility (Ireland).