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.
Bibliographical noteFunding Information:
This study was financially supported by the “ Fonds Economische Structuurversterking (FES)”, Dutch Ministry of Education, Culture and Science grant BEK/BPR-2009/137964-U , “Making the Tree of Life Work”. We thank the CBS technical staff, Arien van Iperen, Ijda Vlug and Trix Merkx (cultures), Marjan Vermaas (photographic plates), and Mieke Starink-Willemse (partial DNA isolation, amplification and sequencing) for their assistance. We would like to thank Dr Christian Scheuer from the Karl-Franzens-University, Dr Bram Hanse from IRS-Institute of Sugar Beet Research, Dr. Agnès Champeil from the ITB-Institut Technique de la Betterave, Dr Anne Lisbet Hansen from NBR-Nordic Beet Research and our colleagues Dr Ulrike Damm and Dr William Quaedvlieg for several freshly collected specimens used in this study. A special thank you is due to our colleague Dr Gerard Verkley, who over the years collected several specimens that were preserved both in herbaria and in culture and were very important for this study. We would also like to thank all the other mycologists who deposited their specimens in the CBS and CPC collection over the years and made this work possible. We would like to thank the curators and staff of the HBG, K, LPS, M, NY and PC herbaria for all the specimens sent for study.
© 2016 CBS-KNAW Fungal Biodiversity Centre
- Multilocus phylogeny
- Plant pathogen
ASJC Scopus subject areas
- Agricultural and Biological Sciences (miscellaneous)