Abstract
In this study, we investigated two unidentified lineages of root-colonizing fungi belonging to the order Pleosporales (Dothideomycetes), which were isolated from Festuca vaginata ( Poaceae ), a dominant grass species in the semiarid sandy grasslands of Hungary. For molecular phylogenetic studies, seven loci (internal transcribed spacer, partial large subunit and small subunit region of nrRNA, partial transcription elongation factor 1-α, RNA polymerase II largest subunit, RNA polymerase II second largest subunit, and ß-tubulin genes) were amplified and sequenced. Based on morphology and multilocus phylogenetic analyses, we found that one lineage belonged to Delitschia chaetomioides P. Karst. ( Delitschiaceae ), and the isolates of the other lineage represented a novel monotypic genus in the family Trematosphaeriaceae (suborder Massarineae). For this lineage, we proposed a new genus, Fuscosphaeria, represented by a single species, F. hungarica . In both lineages, only immature and degenerated sporocarps could be induced. These were sterile, black, globose, or depressed globose structures with numerous mycelioid appendages submerged in culture media or on the surface of autoclaved plant materials. Both species are first reported here as root-colonizing fungi.