First report of Gnomoniopsis smithogilvyi in the United Kingdom
The NPPO of the United Kingdom recently informed the EPPO Secretariat of the first record of Gnomoniopsis smithogilvyi on its territory in association with a shoot canker disease of sweet chestnut (Castanea sativa). In August 2016, symptoms resembling those of Cryphonectria parasitica (EPPO A2 List) were reported on a single plant of C. sativa in a rural area. This small tree was part of a 2 year-old amenity planting in Southern England. Samples were collected and tested by Forest Research (Tree Health Diagnostic and Advisory Service). As the initial tests gave negative results for the presence of C. parasitica, further studies were carried out (isolation, morphological and molecular methods) and confirmed the presence of G. smithogilvyi in October 2016. Investigations could not trace the origin of this finding but discussion is on-going with the land manager. The need for further action will be evaluated through the UK Plant Health Risk Register process.
The pest status of Gnomoniopsis smithogilvyi in the United Kingdom is officially declared as: Transient, under eradication.
EPPO note: G. smithogilvyi was first described in 2012 as the causal agent of nut rot on sweet chestnut (Castanea sativa and C. crenata x C. sativa hybrids) in Australia. The same year, G. castanea was described in Italy as the causal of a nut rot (‘mummificazione bianca delle castagne’), a disease which has been observed in Italy since the second half of the 19th century but whose incidence has increased since 2005 in the north-west (EPPO RS 2013/063). In addition to Italy, G. castanea has also been isolated from rotten nuts from Southeastern France, Southern Switzerland, and a very closely related species (informally called Gnomonia pascoe) has been recorded in New Zealand. Recent studies (morphology, phylogeny) have concluded that all three names referred to a single species and that the name G. smithogilvyi had priority. G. smithogilvyi is associated with nut rot and is also able to cause cankers on twigs and scions that are very similar to the ones caused by Cryphonectria parasitica. On affected nuts, the endosperm becomes chalky, white and sponge-like, resulting in an alteration of flavour. The fungus has also been isolated as an endophyte on chestnut from asymptomatic flowers, leaves and stems. Nut rot is raising increasing concerns in countries where chestnut is grown for fruit production. As a consequence, studies are being carried out to better understand its biology and find possible control methods, in particular in the field of biological control.
According to the literature, G. smithogilvyi occurs in the following countries:
EPPO region: France (Southeast), Italy (Mainland and Sardegna), Switzerland (cantons of Glarus, Graubünden, Ticino), United Kingdom (single tree, under eradication).
Asia: India (Jammu and Kashmir).
Oceania: Australia (New South Wales, Victoria), New Zealand.
Sources
NPPO of the United Kingdom (2016-10).
Additional sources:
Dar MA, Rai M (2015) Gnomoniopsis smithogilvyi, a canker causing pathogen on Castanea sativa: First report. Mycosphere 6(3), 327-336.
Dennert GF, Broggini AL, Gessler C, Storari M (2015) Gnomoniopsis castanea is the main agent of chestnut nut rot in Switzerland. Phytopathologia Mediterranea 54(2), 199−211.
INTERNET
- Vernol D (2014) Principaux problèmes sanitaires de la castanéiculture française. Presentation made at the European Chestnut Meeting (2014-09-11/13). http://www.chestnut-meetings.org/uploads/1/7/0/4/17040934/france_cynips_vernol.pdf
Linaldeddu BT, Deidda A, Scanu B, Franceschini A, Alves A, Abdollahzadeh J, Phillips AJL (2016) Phylogeny, morphology and pathogenicity of Botryosphaeriaceae, Diatrypaceae and Gnomoniaceae associated with branch diseases of hazelnut in Sardinia (Italy). European Journal of Plant Pathology 146(2), 259-279.
Pasche S, Calmin G, Auderset G, Crovadore J, Pelleteret P, Mauch-Mani B, Barja F, Paul B, Jermini M, Lefort F (2016) Gnomoniopsis smithogilvyi causes chestnut canker symptoms in Castanea sativa shoots in Switzerland. Fungal Genetics and Biology 87, 9–21 (abst.).
Pasche S, Crovadore J, Pelleteret P, Jermini M, Mauch-Mani B, Oszako T, Lefort, F (2016) Biological control of the latent pathogen Gnomoniopsis smithogylvyi in European chestnut grafting scions using Bacillus amyloliquefaciens and Trichoderma atroviride. Dendrobiology 75, 113-122.
Shuttleworth LA, Guest DI (2012) In: Crous PW et al. (eds). Fungal Planet description sheets. Gnomoniopsis smithogilvyi. Sheet no. 108, 142-143. http://edepot.wur.nl/240835
Shuttleworth LA, Liew EC, Guest DI (2013) Survey of the incidence of chestnut rot in south-eastern Australia. Australasian Plant Pathology 42, 63-72.
Shuttleworth LA, Walker DM, Guest DI (2015) The chestnut pathogen Gnomoniopsis smithogilvyi (Gnomoniaceae, Diaporthales) and its synonyms. Mycotaxon 130 (4), 929-940.
Visentin I, Gentile S, Valentino D, Gonthier P, Tamietti G, Cardinale F (2012) Gnomoniopsis castanea sp. nov. (Gnomoniaceae, Diapothales) as the causal agent of nut rot in sweet chestnut. Journal of Plant Pathology 94, 411-419.