title: Pythium polare, a new heterothallic oomycete causing brown discolouration of Sanionia uncinata in the Arctic and Antarctic.
abstract: Pythium polare sp. nov. is a new heterothallic oomycete species isolated from fresh water and moss from various locations in both the Arctic and Antarctic. This water mould is able to infect stems and leaves of Sanionia moss (Sanionia uncinata). Pythium polare causes brown discolouration in in vitro inoculation tests at 5 °C after 5 weeks of inoculation. It is characterized by globose sporangia with various lengths of discharge tubes releasing zoospores and aplerotic oospores with usually one to five antheridia. The sexual structures are only produced in a dual culture of antheridial and oogonial isolates. Phylogenetic analysis, based on ITS sequencing, places all isolated strains of P. polare in a unique new clade, hence it is considered a novel species. Pythium canariense and Pythium violae are the most closely related species of P. polare based both on morphology and the phylogenetic analysis.
authors: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan. tojo@plant.osakafu-u.ac.jp
authors: Motoaki
authors: M
authors: Tojo
authors: Pieter
authors: P
authors: van West
authors: Tamotsu
authors: T
authors: Hoshino
authors: Kenichi
authors: K
authors: Kida
authors: Hirokazu
authors: H
authors: Fujii
authors: Akiho
authors: A
authors: Hakoda
authors: Yuki
authors: Y
authors: Kawaguchi
authors: Hermann A
authors: HA
authors: Mühlhauser
authors: Albert H
authors: AH
authors: Van Den Berg
authors: Frithjof C
authors: FC
authors: Küpper
authors: María L
authors: ML
authors: Herrero
authors: Sonja S
authors: SS
authors: Klemsdal
authors: Anne Marte
authors: AM
authors: Tronsmo
authors: Hiroshi
authors: H
authors: Kanda
mesh_terms: D000864:Antarctic Regions; D001110:Arctic Regions; D019068:Bryopsida / Q000382:microbiology*; D016000:Cluster Analysis; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology*; D011775:Pythium / Q000145:classification* / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification*; D017422:Sequence Analysis, DNA; D013172:Spores, Fungal / Q000166:cytology; D014871:Water Microbiology
chemical_list: D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer