title: Phytopythium: molecular phylogeny and systematics.
abstract: The genus Phytopythium (Peronosporales) has been described, but a complete circumscription has not yet been presented. In the present paper we provide molecular-based evidence that members of Pythium clade K as described by Lévesque & de Cock (2004) belong to Phytopythium. Maximum likelihood and Bayesian phylogenetic analysis of the nuclear ribosomal DNA (LSU and SSU) and mitochondrial DNA cytochrome oxidase subunit 1 (COI) as well as statistical analyses of pairwise distances strongly support the status of Phytopythium as a separate phylogenetic entity. Phytopythium is morphologically intermediate between the genera Phytophthora and Pythium. It is unique in having papillate, internally proliferating sporangia and cylindrical or lobate antheridia. The formal transfer of clade K species to Phytopythium and a comparison with morphologically similar species of the genera Pythium and Phytophthora is presented. A new species is described, Phytopythium mirpurense.
authors.affiliation: CBS-KNAW Fungal Biodiversity Centre, P.O. Box 85167, 3508 AD Utrecht, The Netherlands.
authors.forename: A W A M
authors.initials: AW
authors.lastname: de Cock
authors.affiliation: Department of Plant Pathology, Sindh Agriculture University, Tandojam, Pakistan.
authors.forename: A M
authors.initials: AM
authors.lastname: Lodhi
authors.affiliation: Agriculture and Agri-Food Canada, 960 Carling Ave, Ottawa, ON K1A 0C6, Canada;
authors.forename: T L
authors.initials: TL
authors.lastname: Rintoul
authors.affiliation: Agriculture and Agri-Food Canada, 960 Carling Ave, Ottawa, ON K1A 0C6, Canada;
authors.forename: K
authors.initials: K
authors.lastname: Bala
authors.affiliation: Agriculture and Agri-Food Canada, 960 Carling Ave, Ottawa, ON K1A 0C6, Canada;
authors.forename: G P
authors.initials: GP
authors.lastname: Robideau
authors.affiliation: USDA-APHIS-PPQ-Center of Plant Health Science and Technology, Bldg 580, BARC-e, Powder Mill Road, Beltsville, MD 20705, USA.
authors.forename: Z Gloria
authors.initials: ZG
authors.lastname: Abad
authors.affiliation: Department of Plant Pathology and Microbiology, University of California, Riverside, CA 92521, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Coffey
authors.affiliation: Department of Agriculture, University of Karachi, Karachi, Pakistan.
authors.forename: S
authors.initials: S
authors.lastname: Shahzad
authors.affiliation: Agriculture and Agri-Food Canada, 960 Carling Ave, Ottawa, ON K1A 0C6, Canada;
authors.forename: C A
authors.initials: CA
authors.lastname: Lévesque
keywords: COI; LSU; Oomycetes; Oomycota; Peronosporales; Phytopythium; Pythiales; SSU