Multigene phylogeny, taxonomy, and potential biological properties of Pseudoroussoella and Neoroussoella species (Roussoellaceae, Dothideomycetes) from Asteraceae weeds in northern Thailand

In our study, dead stems of two Asteraceae species (weeds) were collected from northern Thailand. Both morphology and multigene phylogeny were used to determine the identity of the taxa. Maximum likelihood and Bayesian inference analyses of combined LSU, SSU, ITS, tef1-α and rpb2 data revealed two new species Pseudoroussoella bidenticola, and Neoroussoella chromolaenae with one new host record of N. entadae. Preliminary investigation into antibacterial properties revealed that our three isolates inhibited the growth of Bacillus subtilis, Escherichia coli, and Staphylococcus aureus. Additionally, we present updated phylogenetic trees for Roussoellaceae, accompanied by detailed descriptions and illustrations of the three identified species.