Snow mould caused by a Pythium sp.: a potential vascular plant pathogen in the maritime Antarctic

• Published in: Plant pathology Vol. 57; no. 6; pp. 1066 - 1072
• Main Authors: Bridge, P.D, Newsham, K.K, Denton, G.J
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.12.2008; Blackwell Publishing Ltd; Blackwell
• Subjects: Biological and medical sciences; Deschampsia antarctica; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; Phytopathology. Animal pests. Plant and forest protection; Pythium; rRNA ITS sequences; Signy Island; snow mould; Antarctic Ocean; Antarctica; Antarctica, South Orkney Is; Antarctica, South Orkney Is., Signy I; Stramenopila; Vegetals; Plant pathology; Plant pathogen; Pythium; Biochemical compound; Deschampsia antarctica; Potential; Oomycota; Island; Signy Island; Plant; snow mould; Ribosomal RNA; rRNA ITS sequences; Polar region; Mould; Nucleic acid
• ISSN: 0032-0862; 1365-3059
• DOI: 10.1111/j.1365-3059.2008.01868.x

The pathogenicity of an isolate of a Pythium species from Signy Island in the South Orkney Islands was tested against the Antarctic hairgrass Deschampsia antarctica. The isolate was found to infect plants at 8[ordinal indicator, masculine]C and to cause foliar and root symptoms similar to those seen in other Pythium infections in grasses. Analysis of ribosomal RNA sequences placed it, together with another isolate from Antarctica, in a clade that included the known snow moulds caused by Pythium spp. Sporangia and oogonia were produced in culture, but the isolate differed from other Pythium spp. in producing chlamydospores in older cultures and plant tissue. This is the first report of a pathogen of an eukaryotic vascular plant in the maritime Antarctic region.