A random subsample (13 g) of fine roots was washed and rinsed with water before DNA extraction using a modified CTABchloroform method. PCR was performed with ITS9mun and ITS4ngsUni primers. Amplicons were barcoded with the Native Barcoding Kit (SQK-NBD114.96, Oxford Nanopore, UK) and sequenced on a MinION (Oxford Nanopore, UK). Basecalling and demultiplexing were conducted using the super-accuracy model in Dorado (v0.5.0, Oxford Nanopore Technologies).