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First Report of Phaeobotryon cupressi Causing Canker of Calocedrus decurrens (Incense-Cedar) in Oregon

2016; American Phytopathological Society; Volume: 100; Issue: 8 Linguagem: Inglês

10.1094/pdis-03-16-0313-pdn

1943-7692

Jerry E. Weiland, Richard A. Sniezko, Michele S. Wiseman, Maryna Serdani, M. L. Putnam,

Yeasts and Rust Fungi Studies

HomePlant DiseaseVol. 100, No. 8First Report of Phaeobotryon cupressi Causing Canker of Calocedrus decurrens (Incense-Cedar) in Oregon PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Phaeobotryon cupressi Causing Canker of Calocedrus decurrens (Incense-Cedar) in OregonJ. E. Weiland, R. A. Sniezko, M. S. Wiseman, M. Serdani, and M. L. PutnamJ. E. WeilandSearch for more papers by this author, R. A. SniezkoSearch for more papers by this author, M. S. WisemanSearch for more papers by this author, M. SerdaniSearch for more papers by this author, and M. L. PutnamSearch for more papers by this authorAffiliationsAuthors and Affiliations J. E. Weiland , USDA-ARS Horticultural Crops Research Laboratory, Corvallis, OR 97330 R. A. Sniezko , USDA-Forest Service Dorena Genetic Resource Center, Cottage Grove, OR 97424 M. S. Wiseman M. Serdani M. L. Putnam , Oregon State University, Botany and Plant Pathology Department, Corvallis 97331. Published Online:8 Jun 2016https://doi.org/10.1094/PDIS-03-16-0313-PDNAboutSectionsSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Since the early 2000s, a canker disease has been noted with increasing frequency on landscape and windbreak specimens of native incense-cedar (Calocedrus decurrens) planted throughout the Willamette Valley in western Oregon. Incense-cedar is valued in low-input landscapes where the disease destroys their ornamental value. Symptoms initially appear as dead, flagging small-diameter branches (≤1 cm) that are scattered throughout the lower crown of the tree. Cankers are constricted with a clear demarcation between living and dead tissue. Over a period of several years, the number and diameter of branches affected increases as the disease progresses up the crown. Symptoms are often more extensive on younger trees and affect a larger proportion of the crown. In 2014 and 2015, Phaeobotryon cupressi was consistently isolated from branch cankers on 45 trees from 13 locations along 200 km of the Willamette Valley. Branch cankers were disinfested for 1 min in 10% bleach, 1 min in 70% ethanol, and then plated on half strength PDA amended with streptomycin at 50 mg/liter (1/2 SPDA). Isolates showed 99% identity with the rDNA ITS sequence (KU896860 to 896863) and 98% identity with the translation elongation factor 1-α (EF1-α) sequence (KU896864) of the ex-type of P. cupressi, GenBank Accession No. FJ919672 (ITS) and FJ919661 (EF1-α), respectively (Abdollahzadeh et al. 2009). Morphological characteristics were consistent with the species description. Cultures were olive brown to gray on PDA. Conidia, produced within pycnidia, were hyaline to brown, thick-walled, oval, aseptate, and measured 27.1 (20.0 to 32.5) × 14.1 (10.0 to17.5) µm from both branch cankers and cultures grown on PDA (4 isolates × 50 spores). Six isolates from several locations were used to inoculate 0.6 to 1 m tall saplings of incense-cedar grown in 11 liter pots, outdoors. Inoculum was produced by growing each isolate on 1/2 SPDA for 1 week at 22°C. For each isolate, two branches were inoculated on two saplings (four branches total) by excising a thin slice of bark (3 mm2), placing a 5-mm-diameter colonized plug on the wound, then covering with Parafilm. Negative controls were inoculated with uncolonized agar plugs. All inoculations were repeated at least 3 weeks later. Approximately 4 to 6 weeks after inoculation, branches inoculated with P. cupressi turned brown and died, while control branches remained healthy. A dark, sunken necrotic lesion extended from the inoculation point toward the base of the branch, and occasionally spread to and killed the main stem. The pathogen was reisolated from all inoculated branches using procedures described above, but was not recovered from controls. Thus, Koch’s postulates were fulfilled. Symptoms appeared more quickly during warm weather in summer (4 weeks) than on saplings inoculated during cool weather in late spring or early fall (5 to 6 weeks). This is the first report of P. cupressi occurring on incense-cedar in Oregon. The pathogen was originally described causing cankers on Cupressus sempervirens in Iran and has been isolated once from Juniperus scopulorum in Kansas (Alves et al. 2013). Similar symptoms have been observed on incense-cedar in its native range in the Cascade mountains of Oregon, but it is unknown if P. cupressi is the causal agent at those locations. Studies are underway to evaluate the extent of this disease in the native and planted range of incense-cedar in the western United States.References:Abdollahzadeh, J., et al. 2009. Persoonia 23:1. https://doi.org/10.3767/003158509X467552 Crossref, ISI, Google ScholarAlves, A., et al. 2013. Eur. J. Plant Pathol. 135:791. https://doi.org/10.1007/s10658-012-0122-2 Crossref, ISI, Google ScholarDetailsFiguresLiterature CitedRelated Vol. 100, No. 8 August 2016SubscribeISSN:0191-2917e-ISSN:1943-7692 Metrics Article History Issue Date: 22 Jul 2016Published: 8 Jun 2016First Look: 18 Apr 2016Accepted: 11 Apr 2016 Pages: 1793-1793 Information© 2016 The American Phytopathological SocietyCited byPhaeobotryon cupressiCABI Compendium, Vol. CABI CompendiumPileospora piceae gen. et sp. nov. (Septorioideaceae, Botryosphaeriales) from Picea rubens28 July 2018 | Mycological Progress, Vol. 18, No. 1-2