Illumina MiSeq amplicon sequencing of root samples
PCR was performed using forward primers ITS3-Mix1-5 and ITS3Oo and a  reverse primer ITS4ngs. Reverse primers were tagged with one of the 93 identifiers (MIDs, 10-12 bases). Each PCR mix contained 1 l DNA, 0.5 l each of the primers (20pmol), 5 l 5xHOT FIREPol Blend Mastermix (Solis Biodyne, Tartu, Estonia) and 18 l PCR grade water (Solis Biodyne, Tartu, Estonia). Samples were run on an Eppendorf Mastercycler (Hamburg, Germany) in duplicate under following conditions: initial 15 min at 95 C; 25 cycles of 30 s at 95 C, 30 s at 55 C, 1 min at 72 C; and a final cycle of 10 min at 72 C.