Pythium polare, a new heterothallic oomycete causing brown discolouration of Sanionia uncinata in the Arctic and Antarctic

Surviving freezing in plant tissues by oomycetous snow molds

“…Oomyceteous snow molds, Pythium species, were reported to be less tolerant to chilling [3] and freezing temperatures than other snow mold taxa [1,2,5,10]. However, Pythium species have often caused snow mold disease on mosses in Polar Regions [11,12].…”

“…Oomyceteous snow molds, Pythium species, were reported to be less tolerant to chilling [3] and freezing temperatures than other snow mold taxa [1,2,5,10]. However, Pythium species have often caused snow mold disease on mosses in Polar Regions [11,12].Snow mold Pythium species were collected from Temperate (Hokkaido, Japan) and Subantarctic Regions (Supplemental Table 1). Mycelial discs (confirmed to be free of sexual and non-sexual organs) were prepared according to Supplemental file and were frozen at À20°C in a programmed freezer (MPF-100, EYELA, Tokyo, Japan) at a rate of 10°C/h in a test tube.…”

Pythium cederbergensesp. nov. and related taxa fromPythiumclade G associated with the South African indigenous plantAspalathus linearis(rooibos)

“…Pythium nagaii have been reported to cause root rot of rice (Oryza sativa L.) seedlings (van der Plaats-Niterink 1981). Pythium polare is a weak pathogen of the Sanionia moss (Sanionia uncinata) and causes brown discoloration of stem leaves (Tojo et al 2012). The pathogenicity of P. canariense has not been investigated.…”

“…Paul (Paul 2002), P. iwayamai S. Ito, P. nagaii S. Ito & Tokunaga, P. okanoganense Lipps, P. paddicum Hirane, P. polare Toja, van West & Hoshino (Tojo et al 2012) and P. violae Chesters & Hickman (Lévesque and de Cock 2004). Representative GenBank sequences and isolates of these species and other related putative new taxa are limited.…”

Typhulacf.subvariabilis, new snow mould in Antarctica

“…The snow moulds Pythium polare and related species occur frequently as pathogens of moss and vascular plants species in the Arctic and Antarctic, chiefly in maritime area (Petrov 1983; Tojo and Newsham 2012; Tojo et al 2012). Two psychrophilic snow moulds Spirorbis borealis and Typhula ishikariensis are also widely distributed not only in the cool temperate zone and frigid zone but also in Arctic regions such as Alaska and the Yukon (Lebeau and Longston 1958; McBeath 2002), Greenland (Hoshino et al 2006), Finnmark (northern Norway: Årsvoll 1975; Matsumoto and Tronsmo 1995; Matsumoto et al 1996), Iceland ( S. borealis not found: Kristinsson and Guðleifsson 1976; Hoshino et al 2004), Lapland (northern Finland and Sweden: Jamalainen 1949, 1957; Ekstrand 1955), Svalbard (Hoshino et al 2003), Russian Arctic (Tkachenko 2013).…”