Heteroverticillium phytelephatis gen. et sp. nov. intercepted from nuts of Phytelephas macrocarpa, with an updated phylogenetic assessment of Nectriaceae.

Abstract

An entry postal parcel with mature nuts of Phytelephas macrocarpa from Togo was inspected at Dalian Customs (China) in December 2021, and four strains were isolated from symptomatic tissues of the nuts. Based on morphological observations and molecular phylogenetic analyses, above strains were identified as a new species which is mainly characterised by the verticillately branching conidiophores. Based on multi-locus phylogenetic analyses, this new species forms a monophyletic clade closely related to Corallomycetella, Paracremonium and Xenoacremonium but could not be accommodated in any known genera of Nectriaceae. Thus, a new genus Heteroverticillium is established to accommodate this new species (H. phytelephatis). To our knowledge, this is the first time that Chinese customs have intercepted a new fungal genus. In addition, we provided an updated backbone tree for the generic relationships in Nectriaceae, which may largely assist future identification of nectriaceous fungi to genus level in quarantine inspections. Based on our analysis, Varicosporellopsis is likely a late synonym of Paracremonium.