title: Multiple Phytophthora species associated with a single riparian ecosystem in South Africa.
abstract: The diversity of Phytophthora spp. in rivers and riparian ecosystems has received considerable international attention, although little such research has been conducted in South Africa. This study determined the diversity of Phytophthora spp. within a single river in Gauteng province of South Africa. Samples were collected over 1 y including biweekly river baiting with Rhododendron indicum leaves. Phytophthora isolates were identified with phylogenetic analyses of sequences for the internal transcribed spacer (ITS) region of the ribosomal DNA and the mitochondrial cytochrome oxidase c subunit I (coxI) gene. Eight Phytophthora spp. were identified, including a new taxon, P. taxon Sisulu-river, and two hybrid species from Cooke's ITS clade 6. Of these, species from Clade 6 were the most abundant, including P. chlamydospora and P. lacustris. Species residing in Clade 2 also were encountered, including P. multivora, P. plurivora and P. citrophthora. The detection of eight species in this investigation of Phytophthora diversity in a single riparian river ecosystem in northern South Africa adds to the known diversity of this genus in South Africa and globally.
authors.affiliation: Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0001, South Africa jan.nagel@fabi.up.ac.z.
authors.forename: Jan H
authors.initials: JH
authors.lastname: Nagel
authors.affiliation: Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0001, South Africa.
authors.forename: Bernard
authors.initials: B
authors.lastname: Slippers
authors.affiliation: Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0001, South Africa.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Wingfield
authors.affiliation: Department of Plant Sciences, University of the Free State, Bloemfontein 9300, South Africa.
authors.forename: Marieka
authors.initials: M
authors.lastname: Gryzenhout
mesh_terms: D004271:DNA, Fungal / Q000235:genetics; D021901:DNA, Intergenic / Q000235:genetics; D017753:Ecosystem; D010802:Phylogeny; D010838:Phytophthora / Q000145:classification* / Q000235:genetics; D045483:Rivers; D013019:South Africa
chemical_list: D004271:DNA, Fungal; D021901:DNA, Intergenic
keywords: Clade 6; P. citrophthora; P. lacustris; P. multivora; P. plurivora; P. taxon Sisulu-river; Phytophthora chlamydospora; South Africa