- Lead scientist
- Geoff Denton
- Partners
- Professor Paul Bridge, British Antarctica Survey
- Start date
- 2006
- End date
- 2007
- Keywords
Pythiums, Pythium, snow mould, Antarctica, grasses, pathogenicity
- Benefits to gardeners
Ongoing RHS research is identifying Pythium species as potentially a major garden pathogen.
New Pythium species are increasingly being detected and identified through surveys of Pythium species habitats, such as woodlands and waterways. Climate change is forecasted to drastically alter UK weather. Studying pathogens in areas of extreme weather conditions will give an insight and advantage into understanding their biology.
These pathogens could have additional potential for development of biopesticides.
- The problem
A new Pythium species has been identified from Antarctica. In collaboration with BAS, studies have shown this to be within ‘Clade G’ through phylogeny of the Pythium genus. ‘Clade G’ includes the snow moulds, which cause dieback and eventually death of monocotyledenous plants.
In Antarctica there are only two naturally occurring vascular plants Deschampsia antarctica (Antarctic hairgrass) and Colobanthus quitensis (Antarctic pearlwort). Of these Deschampsia antarctica is the only monocot and therefore a possible natural host.
Summer dead patches of D. antarctica have been anecdotally recorded for at least 20 years. This will investigate whether this new Pythium species is pathogenic to plants.
- Approach
Initial studies compared morphology and genetic sequences from the Antarctic fungus to other known fungi. This enabled the Antarctic fungus to be classified as a Pythium species and specifically within ‘Clade G’.
Pythium ‘Clade G’ contains important pathogens of monocotyledonous plants. Deschampsia antarctica is the only naturally occurring monocotyledonous plant in the Antarctic region and therefore chosen to undertake the pathogenicity trial.
Deschampsia antarctica seeds were vernalised and grown to produce small plants. Half of these were inoculated at the roots with the Pythium species, which was grown on a nutrient rich media. The remaining plants were used as controls. Assessment of the D. antarctica plants found sporangia within the plants material. The Pythium species was re-isolated from root and leaf samples and found to be present within the inoculated plants and not the control plants. Root measurements showed inoculated plants having increased root length, but marked absence of root hairs and less total root mass.
This is the first report of a pathogen of an eukaryotic vascular plant in the Antarctica region.
- Further information
Read more about slime moulds on lawns
Advice about damping off
News from CABI
Read about Pythium: A garden pathogen
- References
Bridge P D and Denton G J (2007). Isolation of diverse viable fungi from the larvae of the introduced chironomid Eretmoptera murphyi on Signy Island. Polar Biol 30 (7): 935-937 (PDF)
Bridge P D, Newsham K K, Denton G J (2008). Snow mould caused by a Pythium sp.: a potential vascular plant pathogen in the maritime Antarctic. Plant Pathology, 57, 1066-1072.