Two new Neohelicomyces species (Tubeufiaceae, Tubeufiales) associated with Coffea arabica L. in Yunnan Province, China

Abstract

Neohelicomyces species comprise a group of helicosporous hyphomycetes, with over 90 % of the currently accepted taxa reported from China, occurring in both freshwater and terrestrial habitats. Although the genus has been increasingly documented in recent years, its presence in crop-related ecosystems remains poorly understood, as most species have been reported from unknown hosts. In this study, a survey of fungi associated with Coffea arabica in Yunnan Province, China, was conducted, and fruiting bodies of helicosporous hyphomycetes were found on dead branches of coffee plants.

Based on the morphological characteristics of conidiophores, conidiogenous cells, and conidia, in combination with multigene phylogenetic analyses (ITS, LSU, rpb 2, and tef 1 - α), two novel species of Neohelicomyces (N. coffeae and N. puerensis) were identified. Morphologically, N. coffeae differs from closely related species N. edgeworthiae by having shorter conidiophores, longer conidiogenous cells, and smaller, multi-septate conidia (vs. aseptate in N. edgeworthiae), while N. puerensis differs from its close relative N. dehongensis by having narrower and distinctly multi-septate conidia, more tightly coiled conidial filaments, and unbranched conidiophores.

These results expand the known diversity of Neohelicomyces and contribute to a better understanding of fungal assemblages associated with coffee plants in subtropical China. In addition, detailed descriptions, illustrations, and phylogenetic trees are provided.