Forest soils: A species-rich habitat for Cylindrocladiella.

Species of Cylindrocladiella are soil-borne fungi that are distributed in temperate, sub-tropical and tropical regions of the world. Very little is known regarding the biology of these fungi that are mostly considered as saprobes, but there have also been reports of pathogenicity in some cases. Prior to this study, 46 species of Cylindrocladiella were known based on DNA sequence comparisons and phylogenetic analyses. Only seven of those species have been reported from China, some of which were associated with diseases of woody plants. In this study, soil samples were collected from natural forests and plantations in eight provinces (autonomous regions) of northeastern, central, southeastern, southwestern, and southern regions of China. A total of 914 soil samples were analysed, resulting in 407 Cylindrocladiella isolates. They were identified based on morphological characteristics and phylogenetic analyses of DNA sequence data for the tef1, tub2, his3, and ITS regions. This resulted in the identification of eight known, and 22 novel species. Cylindrocladiella spp. tended to be widely distributed in forest soils across a wide range of climatic zones. The species diversity in warm areas was higher than in cooler areas. Of the 68 species now recognised and verified based on DNA data, these fungi are known from more than 25 countries, of which 57 species were isolated from soils, 18 from plant tissues, and nine from both soils and plant tissues. Species with wide geographic distributions including putative pathogens such as, Cy. peruviana and Cy. parva that have been found on multiple plant species, while others are confined to more limited niches. The exceptionally large number of new species found in this study suggests that Cylindrocladiella species have been poorly sampled and that many more are likely to be found in warm and humid environments. Overall, this study provides a foundation for future investigations aimed at clarifying the evolutionary relationships, ecology, and pathology of this interesting and little understood genus. Citation: Zhou WW, Dong HB, Zhou HX, Crous PW, Wingfield MJ, Chen SF (2026). Forest soils: A species-rich habitat for Cylindrocladiella. Persoonia 56: 548-605. doi: 10.3114/persoonia.2026.56.09.