Phylogeny and taxonomy of the genera of Erysiphaceae, part 7: Phyllactinieae.

The seventh part of this series devoted to the phylogeny and taxonomy of powdery mildews presents the phylogeny and taxonomy of species assigned to the genera Leveillula, Phyllactinia, Pleochaeta, and Queirozia (Erysiphaceae tribe Phyllactinieae). Phylogenetic trees based on multiple loci (ITS+28S, CAM, GADPH, GS, IGS, RPB2, and TUB) are presented. All species with available sequence data are included. The present analyses aim at providing a reference for analyses of powdery mildews of tribe Phyllactinieae. A special focus is on the generic distinction at the base of tribe Phyllactinieae and between Leveillula and Phyllactinia. The inclusion of a larger number of phylogenetically basal Phyllactinia spp. and multiple loci allowed a better insight into the phylogeny of tribe Phyllactinieae and confirmed that Leveillula spp. are nested within the Phyllactinia clade. As a consequence, Leveillula is reduced to synonymy with Phyllactinia. Additionally, Queirozia was found to be nested within the Pleochaeta clade, and as such we have reduced Queirozia to synonymy with Pleochaeta. Multiple species have been sequenced for the first time, in particular multiple North American species. Erysiphe betulae, E. orbicularis, E. polychaeta, E. saxaouli, Phyllactinia antarctica, Ph. broussonetiae-kaempferi, Ph. hamamelidis, Ph. kakicola, Ph. pyri-serotinae, Ph. salmonii, Ph. zanthoxylicola, Uncinula lynchii, and U. shiraiana are epitypified. The new species Ph. amelanchieris, sp. nov. Ph. fraxini-pennsylvanicae, sp. nov. and Ph. oemleriae, sp. nov. are described, and the new combinations Phyllactinia buddlejae, Ph. cleomes, Ph. cylindrospora, Ph. farinosa, Ph. golovinii, Ph. guilanensis, Ph. jaczewskii, Ph. lactucae-seriolae, Ph. lactucarum, Ph. lanugiosa, Ph. lappae, Ph. mindii, Ph. oxalidicola, Ph. picridis, Ph. rubiae, Ph. saxaoulii, Ph. taurica, Ph. thevenotiae, Ph. ulmi (comb. et stat. nov.), Ph. verbasci, Ph. wissadulae, and Pleochaeta erysiphoides are introduced. Furthermore, Phyllactinia sect. Basiphyllactinia, sect. nov. Phyllactinia sect. Leveillula, comb. et stat. nov. and Pleochaeta sect. Ovulariopsis, comb. et stat. nov. are presented.