Phylogeny and taxonomy of the genera of Erysiphaceae, part 4: Erysiphe (the “Uncinula lineage”)

ABSTRACT

This is the fourth contribution within an ongoing series dedicated to the phylogeny and taxonomy of powdery mildews. This particular installment undertakes a comprehensive evaluation of a group previously referred to as the “Uncinula lineage” within Erysiphe. The genus Erysiphe is too large to be assessed in a single paper; thus, the treatment of Erysiphe is split into three parts, according to phylogenetic lineages. The first paper, presented here, discusses the most basal lineage of Erysiphe and its relationship to allied basal genera within tribe Erysipheae (i.e., Brasiliomyces and Salmonomyces). ITS+28S analyses are insufficient to resolve the basal assemblage of taxa within the Erysipheae. Therefore, phylogenetic multilocus examinations have been carried out to better understand the evolution of these taxa. The results of our analyses favor maintaining Brasiliomyces, Bulbomicroidium, and Salmonomyces as separate genera, at least for the interim, until further phylogenetic multilocus data are available for additional basal taxa within the Erysipheae. The current analyses also confirmed previous results that showed that the “Uncinula lineage” is not exclusively composed of Erysiphe species of sect. Uncinula but also includes some species that morphologically align with sect. Erysiphe, as well as species that had previously been assigned to Californiomyces and Typhulochaeta. Numerous sequences of Erysiphe species from the “Uncinula lineage” have been included in the present phylogenetic analyses and were confirmed by their position in well-supported species clades. Several species have been sequenced for the first time, including Erysiphe clintonii, E. couchii, E. geniculata, E. macrospora, and E. parvula. Ex-type sequences are provided for 16 taxa including E. nothofagi, E. trinae, and E. variabilis. Epitypes are designated and ex-epitype sequences are added for 18 taxa including Erysiphe carpophila, E. densa, and U. geniculata var. carpinicola. The new species Erysiphe canariensis is described, and the new names E. hosagoudarii and E. pseudoprunastri and the new combination E. ampelopsidis are introduced.

KEYWORDS:

• Evolution
• Helotiales
• ITS-28S rDNA
• multilocus analysis
• powdery mildews
• 1 new taxa

ACKNOWLEDGMENTS

We would like to thank the curation team at BPI, FH, GAM, NCSLG, and NYS for helping with the herbarium specimens. We would like to thank Tom Potterfield and Elan Alford from the Mt. Cuba Center, Cindy Newlander from the Denver Botanic Gardens, and David Boufford at the Harvard Herbaria for help with specimen collections. Our sincere thanks are due to Susumu Takamatsu (Japan) for his support of providing numerous specimens relevant for the present examinations, and to Volker Kummer (Germany) for the collections of Erysiphe canariensis.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the author(s).

SUPPLEMENTARY MATERIAL

Supplemental data for this article can be accessed online at https://doi.org/10.1080/00275514.2023.2230853.

Additional information

Funding

We would like to thank the Daniel E. Stuntz Memorial Foundation, the Puget Sound Mycological Society, and the Sonoma County Mycological Association for funding this research.