Multigene Phylogeny Reveals Endophytic Xylariales Novelties from Dendrobium Species from Southwestern China and Northern Thailand.

Xylariales are common endophytes of Dendrobium . However, xylarialean species resolution remains difficult without sequence data and poor sporulation on artificial media and asexual descriptions for only several species and old type material. The surface-sterilized and morph-molecular methods were used for fungal isolation and identification. A total of forty-seven strains were identified as twenty-three species belonging to Apiosporaceae, Hypoxylaceae, Induratiaceae, and Xylariaceae. Five new species- Annulohypoxylon moniliformis , Apiospora dendrobii , Hypoxylon endophyticum , H. officinalis and Nemania dendrobii were discovered. Three tentative new species were speculated in Xylaria . Thirteen known fungal species from Hypoxylon , Nemania , Nigrospora , and Xylaria were also identified. Another two strains were only identified at the genus and family level ( Induratia sp., Hypoxylaceae sp.). This study recorded 12 new hosts for xylarialean endophytes. This is the first report of Xylariales species as endophytes from Dendrobium aurantiacum var. denneanum , D. cariniferum , D. harveyanum , D. hercoglossum , D. moniliforme , and D. moschatum . Dendrobium is associated with abundant xylarialean taxa, especially species of Hypoxylon and Xylaria . We recommend the use of oat agar with low concentrations to induce sporulation of Xylaria strains.