Taxonomic revision of Neodidymelliopsiswith N. cynanchisp. nov., associated with Cynanchum sibiricumleaf spot in Xinjiang, China

ABSTRACTDuring surveys of plant pathogens in the desert regions of Xinjiang Province, China, a leaf spot was observed on Cynanchum sibiricum. The suspected fungus was isolated and identified using morphology and molecular phylogeny. Morphologically, the fungus was similar to Neodidymelliopsisspecies. Phylogenetic analyzes of combined internal transcribed spacer (ITS); the large subunit of the ribosomal rDNA (LSU); RNA polymerase II the second largest subunit (rpb2), and β-tubulin gene (tub2) sequences showed that our isolates formed a distinct monophyletic lineage in Neodidymelliopsis. This new clade is identified as Neodidymelliopsis cynanchisp. nov. based on the phylogenetic and morphological evidence. In addition, N. urticaeis synonymized with N. cannabisbased on morphology and phylogeny. Furthermore, we emphasize that in-depth revisions are required to assure the taxonomic status of N. sambuci, N. tinkyukukuand N. salvia.This is the first report of Neodidymelliopsisspecies associated with C. sibiricumleaf spot. The results expand our knowledge of Didymellaceae taxa and microfungi associated with desert environments in China.