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 <i>Leveillula, Phyllactinia, Pleochaeta</i>, and <i>Queirozia</i> (Erysiphaceae tribe Phyllactinieae). Phylogenetic trees based on multiple loci (ITS+28S, <i>CAM, GADPH, GS</i>, IGS, <i>RPB2</i>, and <i>TUB</i>) 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 <i>Leveillula</i> and <i>Phyllactinia</i>. The inclusion of a larger number of phylogenetically basal <i>Phyllactinia</i> spp. and multiple loci allowed a better insight into the phylogeny of tribe Phyllactinieae and confirmed that <i>Leveillula</i> spp. are nested within the <i>Phyllactinia</i> clade. As a consequence, <i>Leveillula</i> is reduced to synonymy with <i>Phyllactinia</i>. Additionally, <i>Queirozia</i> was found to be nested within the <i>Pleochaeta</i> clade, and as such we have reduced <i>Queirozia</i> to synonymy with <i>Pleochaeta</i>. Multiple species have been sequenced for the first time, in particular multiple North American species. <i>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</i>, and <i>U. shiraiana</i> are epitypified. The new species <i>Ph. amelanchieris</i>, sp. nov. <i>Ph. fraxini-pennsylvanicae</i>, sp. nov. and <i>Ph. oemleriae</i>, sp. nov. are described, and the new combinations <i>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</i> (comb. et stat. nov.), <i>Ph. verbasci, Ph. wissadulae</i>, and <i>Pleochaeta erysiphoides</i> are introduced. Furthermore, <i>Phyllactinia</i> sect. <i>Basiphyllactinia</i>, sect. nov. <i>Phyllactinia</i> sect. <i>Leveillula</i>, comb. et stat. nov. and <i>Pleochaeta</i> sect. <i>Ovulariopsis</i>, comb. et stat. nov. are presented.