Synhelminthosporium gen. et sp. nov. and Two New Species of Helminthosporium (Massarinaceae, Pleosporales) from Sichuan Province, China.

Helminthosporium is a polyphyletic genus in Massarinaceae (Pleosporales). Species of Helminthosporium are characterized by having septate and erect conidiophores, acro-pleurogenous and distoseptate conidia with a ring-shaped scar at the base. During a survey of fungal diversity in Sichuan Province, China, six Helminthosporium -like isolates were collected from dead branches of unknown trees. Five barcodes, including ITS (ITS1-5.8S-ITS2), SSU, LSU, TEF1 , and RPB2 were amplified and sequenced. Morphological examination and multi-locus phylogenetic analyses revealed two new Helminthosporium species ( H. chengduense sp. nov., and H. chinense sp. nov.), a new genus ( Synhelminthosporium gen. nov.) with a type species Synhelminthosporium synnematoferum sp. nov., and two known species ( Helminthosporium submersum and H. velutinum ) within Massarinaceae. The new genus Synhelminthosporium differs from the phylogenetically closest genus Helminthosporium by producing synnematous conidiophores. This work expands our understanding of the diversity of Helminthosporium -like taxa in Sichuan Province, China.