Didymellaceae species associated with Convolvulaceae plants, with description of three new species

Didymellaceae is one of the largest families in the Pleosporales, encompassing main genera of Phoma-like fungi including Ascochyta, Didymella, and Stagonosporopsis and representing underestimated biodiversity. Plants in the Convolvulaceae often grow as weeds in many climates and host a wide range of fungi in the Didymellaceae. This study identified 22 Didymellaceae strains isolated from plants in the Convolvulaceae according to the consolidated species concept (CSC) using phylogenetic, micromorphological, and cultural features. Multilocus phylogenetic analysis inferred from nucleotide sequences of the internal transcribed spacer (ITS), large subunit (28S) of ribosomal DNA, partial DNA-directed RNA polymerase II subunit (rpb2), and β-tubulin (tub2) genes revealed well-supported monophyletic clades corresponding to 16 Didymellaceae species. Reported here for the first time from the Convolvulaceae hosts are Didymella americana, D. bellidis, D. glomerata, D. pomorum, D. segeticola, D. sinensis, D. tanaceti, Nothophoma brennandiae, N. gossypiicola, Phomatodes nebulosa, Stagonosporopsis caricae, S. heliopsidis, and S. inoxydabilis. Additionally, three new species were described: Didymella pseudomacrophylla, sp. nov. Epicoccum convolvulicola, sp. nov. and Epicoccum pseudoplurivorum, sp. nov. Seven species are reported for the first time from Russia: D. bellidis, D. segeticola, D. sinensis, D. tanaceti, N. brennandiae, P. nebulosa, and S. caricae, and one species, S. heliopsidis, for the first time from Kazakhstan.