Citizen science project reveals high diversity in Didymellaceae (Pleosporales, Dothideomycetes)
Lingwei Hou, Margarita Hernández‐Restrepo, J.Z. Groenewald, Lei Cai, P.W. Crous
Abstract
Fungal communities play a crucial role in maintaining the health of managed and natural soil environments, which directly or indirectly affect the properties of plants and other soil inhabitants. As part of a Citizen Science Project initiated by the Westerdijk Fungal Biodiversity Institute and the Utrecht University Museum, which aimed to describe novel fungal species from Dutch garden soil, the diversity of Didymellaceae , which is one of the largest families in the Dothideomycetes was investigated. A preliminary analysis of the ITS and LSU sequences from the obtained isolates allowed the identification of 148 strains belonging to the family. Based on a multi-locus phylogeny of a combined ITS, LSU, rpb2 and tub2 alignment, and morphological characteristics, 20 different species were identified in nine genera, namely Ascochyta , Calophoma , Didymella , Juxtiphoma , Nothophoma , Paraboeremia , Phomatodes , Stagonosporopsis , and Xenodidymella . Several isolates confirmed to be ubiquitous plant pathogens or endophytes were for the first time identified from soil, such as Ascochyta syringae , Calophoma clematidis - rectae , and Paraboeremia litseae . Furthermore, one new genus and 12 novel species were described from soil: Ascochyta benningiorum sp. nov. , Didymella degraaffiae sp. nov. , D. kooimaniorum sp. nov. , Juxtiphoma kolkmaniorum sp. nov. , Nothophoma brennandiae sp. nov. , Paraboeremia rekkeri sp. nov. , P. truiniorum sp. nov. , Stagonosporopsis stuijvenbergii sp. nov. , S. weymaniae sp. nov. , Vandijckomycella joseae gen. nov. et sp. nov. , V. snoekiae sp. nov. , and Xenodidymella weymaniae sp. nov . From the results of this study, soil was revealed to be a rich substrate for members of Didymellaceae , several of which were previously known only from diseased or apparently healthy plant hosts.