Queirozia turbinata (Phyllactinieae, Erysiphaceae): a powdery mildew with a dematiaceous anamorph Jose ´ R. LIBERATO a,1, *, Robert W. BARRETO a , Seiko NIINOMI b , Susumu TAKAMATSU b a Departamento de Fitopatologia, Universidade Federal de Vic ¸osa 36571-000, Vic ¸osa, MG, Brazil b Laboratory of Plant Pathology, Faculty of Bioresources, Mie University, Tsu 514-8507, Japan article info Article history: Received 15 November 2005 Accepted 16 January 2006 Published online 17 April 2006 Corresponding Editor: David L. Hawksworth Keywords: Ascomycota Hyphomycetes Molecular phylogenetics Pleochaeta Streptopodium abstract The powdery mildew monotypic genus Queirozia was reduced to a synonym of Pleochaeta in 1982. Now, a re-examination of the type material of Queirozia and of two other specimens showed that Queirozia turbinata has a very distinct combination of characters that do not allow its placement within Pleochaeta. It has forked special aerial hyphae, subclavate and predominantly lemon-shaped conidia, and both conidiophores and conidia varying from greyish to yellowish brown (a feature that appears to be unique for this fungus within the Erysiphales). This may represent the first dematiaceous anamorphic powdery mildew known to science. This fungus also has hemiendophytic mycelium, a character considered almost exclusive to the tribe Phyllactinieae. The outer wall surface pattern of wrinkled and turgid conidia of Q. turbinata as observed under the SEM is different from those presented in the literature for this tribe. Molecular analysis showed that Q. turbinata belongs to the tribe Phyllactinieae and is phylogenetic closer to Pleochaeta than to Leveillula or Phyllactinia. It is therefore acknowledged that Queirozia is closely related to Pleocheta but too distinct morphologically from this genus to be accepted as a synonym. Emended descriptions of Queirozia and Q. turbinata are presented. ª 2006 The British Mycological Society. Published by Elsevier Ltd. All rights reserved. Introduction The powdery mildews (Erysiphaceae, Ascomycota) are biotro- phic plant pathogenic fungi classified in five tribes (Braun et al. 2002). Four out of these five tribes have an exclusively ex- ternal mycelium and anamorphic states belonging to the ge- nus Oidium. Their conidia are hyaline and ellipsoid, ovoid, cylindrical or doliiform, produced either singly or in chains (Braun et al. 2002). The fifth tribe Phyllactinieae includes the genera Phyllactinia (anamorph Ovulariopsis), Leveillula (ana- morph Oidiopsis) and Pleochaeta (anamorph Streptopodium) which typically have hemiendophytic (partly external and partly internal) mycelia in common. Their conidia are hyaline and lanceolate, clavate, obclavate or cylindrical and they usu- ally are produced singly and are bigger than the conidia of Oidium (Braun 1987; Boesewinkel 1980). The three anamorphic genera in the tribe Phyllactinieae are distinguishable according to the origin of conidiophores and conidial shape (Braun 1987). Oidiopsis, as well as Streptopodium, produce dimorphic conidia. The first conidium formed on a conidiophore (primary conidium) is apically pointed or lance- olate whereas all other conidia (secondary conidia) are ellip- soid to cylindrical and rounded to truncate at the apex. However, Oidiopsis has conidiophores originating from the * Corresponding author. E-mail address: jose.liberato@dpi.qld.gov.au 1 Current address: Department of Primary Industries and Fisheries, Plant Pathology Herbarium, 80 Meiers Road, Indooroopilly, Qld 4068, Australia. available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/mycres mycological research 110 (2006) 567 – 574 0953-7562/$ – see front matter ª 2006 The British Mycological Society. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.mycres.2006.01.012