Ramularia is a species-rich genus that harbours plant pathogens responsible for yield losses to many important crops, including barley, sugar beet and strawberry. Species of Ramularia are hyphomycetes with hyaline conidiophores and conidia with distinct, thickened, darkened, refractive conidiogenous loci and conidial hila, and Mycosphaerella sexual morphs. Because of its simple morphology and general lack of DNA data in public databases, several allied genera are frequently confused with Ramularia. In order to improve the delimitation of Ramularia from allied genera and the circumscription of species within the genus Ramularia, a polyphasic approach based on multilocus DNA sequences, morphological and cultural data were used in this study. A total of 420 isolates belonging to Ramularia and allied genera were targeted for the amplification and sequencing of six partial genes. Although Ramularia and Ramulariopsis proved to be monophyletic, Cercosporella and Pseudocercosporella were polyphyletic. Phacellium isolates clustered within the Ramularia clade and the genus is thus tentatively reduced to synonymy under Ramularia. Cercosporella and Pseudocercosporella isolates that were not congeneric with the ex-type strains of the type species of those genera were assigned to existing genera or to the newly introduced genera Teratoramularia and Xenoramularia, respectively. Teratoramularia is a genus with ramularia-like morphology belonging to the Teratosphaeriaceae, and Xenoramularia was introduced to accommodate hyphomycetous species closely related to Zymoseptoria. The genera Apseudocercosporella, Epicoleosporium, Filiella, Fusidiella, Neopseudocercosporella, and Mycosphaerelloides were also newly introduced to accommodate species non-congeneric with their purported types. A total of nine new combinations and 24 new species were introduced in this study.
Keywords: Acrodontium fagicola Videira & Crous; Acrodontium luzulae Videira & Crous; Acrodontium pigmentosum Videira & Crous; Apseudocercosporella Videira & Crous; Apseudocercosporella trigonotidis Videira, H.D. Shin & Crous; Barcoding; Cercosporella catenulata Videira & Crous; Cercosporella gossypii Speg.; Cercosporoid; Crocysporium rubellum Bonord.; Cylindrosporium heraclei Oudem.; Epicoleosporium Videira & Crous; Epicoleosporium ramularioides Videira, H.D. Shin & Crous; Filiella Videira & Crous; Filiella pastinacae (P. Karst.) Videira & Crous; Fusoidiella Videira & Crous; Fusoidiella depressa (Berk. & Broome) Videira & Crous; Fusoma inaequale Preuss; Multilocus phylogeny; Mycosphaerella; Mycosphaerelloides Videira & Crous; Mycosphaerelloides madeirae (Crous & Denman) Videira & Crous; Neopseudocercosporella Videira & Crous; Neopseudocercosporella brassicae (Chevall.) Videira & Crous; Neopseudocercosporella capsellae (Ellis & Everh.) Videira & Crous; Ovularia tovarae Sawada; Plant pathogen; Ramularia acroptili Bremer; Ramularia alangiicola Videira, H.D. Shin & Crous; Ramularia aplospora Speg.; Ramularia armoraciae Fuckel; Ramularia beticola Fautrey & Lambotte; Ramularia cerastiicola (Crous) Videira & Crous; Ramularia collo-cygni B. Sutton & J.M. Waller; Ramularia euonymicola Videira, H.D. Shin, U. Braun & Crous; Ramularia gaultheriae Videira & Crous; Ramularia geranii Fuckel; Ramularia geraniicola Videira & Crous; Ramularia kriegeriana Bres; Ramularia lamii Fuckel var. lamii; Ramularia malicola Videira & Crous; Ramularia neodeusta Videira & Crous; Ramularia osterici Videira, H.D. Shin & Crous; Ramularia pusilla Unger; Ramularia rumicicola Videira, H.D. Shin & Crous; Ramularia stellariicola (M.J. Park et al.) Videira, H.D. Shin & Crous; Ramularia trigonotidis Videira, H.D. Shin & Crous; Ramularia vallisumbrosae Cavara; Ramularia variabilis Fuckel; Ramularia veronicicola Videira & Crous; Ramularia weberiana Videira & Crous; Ramulariopsis pseudoglycines Videira, Crous & Braun; Sphaerulina chaenomelis (Y. Suto) Videira, U. Braun, H.D. Shin & Crous; Sphaerulina koreana (Crous et al.) Videira, H.D. Shin & Crous; Teratoramularia Videira, H.D. Shin & Crous; Teratoramularia infinita Videira & Crous; Teratoramularia kirschneriana Videira & Crous; Teratoramularia persicariae Videira, H.D. Shin & Crous; Teratoramularia rumicicola Videira, H.D. Shin & Crous; Xenoramularia Videira, H.D. Shin & Crous; Xenoramularia arxii Videira & Crous; Xenoramularia neerlandica Videira & Crous; Xenoramularia polygonicola Videira, H.D. Shin & Crous.