W B.a 1-3 A
Environmental DNA was extracted from soil and root samples using the DNeasy PowerSoil Pro Kit (QIAGEN, Hilden, Germany) following the manufacturers protocol. The fungal 18S rRNA (AMF) region was amplified using primers AML1/AML2, and PCR products were purified, quantified, and pooled in equimolar concentrations. Libraries were prepared according to the Illumina 16S Metagenomic Sequencing Library Preparation protocol and sequenced on an Illumina MiSeq platform (2  250 bp paired-end).