nothing special, simply use any fungus isolation kit reagent or cTAB protocol mentioned in Sambrook Molecular cloning manual. Thanks.

DNA isolation should be straightforward, as mentioned above (e.g. we use Zymo or Omega bio-tek kits). For PCR, I've successfully amplified barcode genes by directly adding a small weft of mycelia from the aerial hyphae growing on a fresh culture plate, to the PCR reagents (working Taq master mix + primers) in a tube, with an added initial 5-10 min 95C lysis program step. ITS PCRs are good PCR-positive controls and TEF1a is considered the quickest barcode sequence for most species (https://www.fusarium.org/; Article Internet-Accessible DNA Sequence Database for Identifying Fu...

https://pubs.acs.org/doi/10.1021/acs.jnatprod.6b01085