2.3.4. Screening of mutants
F. velutipes mycelia were treated with the mutagen at doses
with a lethality rate of 80–85% according to method in Section
2.3.3 before they were transferred into the PDA plates. The
mycelia were incubated at 30 ◦C for 24 h in darkness and then
at high tolerance temperature in darkness for the next 15 d. The
mutant strains that grew and maintained normal colony morphologies
were selected and designated as the high-temperature
strains. This procedure was repeated six times with mutants that
were previously treated with the same mutagenesis conditions.
Finally, the mycelia that maintained stable, high-temperature tolerance
were subjected to antagonistic testing to identify the true
mutants.