Artigo Acesso aberto Revisado por pares

Occurrence of Phacidiopycnis washingtonensis Causing Speck Rot on Stored Pink Lady Apple Fruit in Chile

2015; American Phytopathological Society; Volume: 100; Issue: 1 Linguagem: Inglês

10.1094/pdis-02-15-0167-pdn

ISSN

1943-7692

Autores

Gonzalo A. Díaz, Juan Pablo Zóffoli, Mauricio Lolas, Antonio Blanco, B. A. Latorre, Enrique Ferrada, Karina Elfar, Paulina Naranjo,

Tópico(s)

Fungal Plant Pathogen Control

Resumo

HomePlant DiseaseVol. 100, No. 1Occurrence of Phacidiopycnis washingtonensis Causing Speck Rot on Stored Pink Lady Apple Fruit in Chile PreviousNext DISEASE NOTES OPENOpen Access licenseOccurrence of Phacidiopycnis washingtonensis Causing Speck Rot on Stored Pink Lady Apple Fruit in ChileG. A. Díaz, J. P. Zoffoli, M. Lolas, A. Blanco, B. A. Latorre, E. E. Ferrada, K. Elfar, and P. NaranjoG. A. DíazSearch for more papers by this author, J. P. ZoffoliSearch for more papers by this author, M. LolasSearch for more papers by this author, A. BlancoSearch for more papers by this author, B. A. LatorreSearch for more papers by this author, E. E. FerradaSearch for more papers by this author, K. ElfarSearch for more papers by this author, and P. NaranjoSearch for more papers by this authorAffiliationsAuthors and Affiliations G. A. Díaz , Laboratorio de Patología Frutal, Facultad de Ciencias Agrarias, Universidad de Talca, Casilla 747-721; Talca, Chile J. P. Zoffoli , Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Casilla 306-22, Santiago, Chile M. Lolas , Laboratorio de Patología Frutal, Facultad de Ciencias Agrarias, Universidad de Talca, Casilla 747-721, Talca, Chile A. Blanco B. A. Latorre E. E. Ferrada K. Elfar P. Naranjo , Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Casilla 306-22, Santiago, Chile. Published Online:25 Nov 2015https://doi.org/10.1094/PDIS-02-15-0167-PDNAboutSectionsSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Chilean apple (Malus × domestica Borkh.) industry has a production area of 37,207 ha (ODEPA 2015). Recently, speck rot, a new postharvest rot of stored apple caused by Phacidiopycnis washingtonensis Xiao & J.D. Rogers, has been reported in Washington State, U.S.A., and Germany (Kim and Xiao 2006; Weber 2011). Speck rot was observed during storage (150 to 180 days; 0°C) of Pink Lady apples harvested from orchards in Linares (35°52′S; 71°37′W) in the south-central region of Chile during 2014. Speck rot was characterized by an initial light brown skin discoloration that progressed to dark brown to black, with a firm rubbery texture that affected part of the fruit or the entire fruit. Superficial or partially immersed black pycnidia were observed on the surface of the decayed areas. Internally decayed tissue was spongy to firm with a brown-black to black appearance and could not be separated from apparently healthy tissue (Weber 2011). Fifteen diseased fruits were superficially disinfested using 75% ethanol for 30 s and cut. Small fragments (2 to 3 mm in length) were collected from the margins of internal diseased tissues and aseptically placed on acidified potato dextrose agar (APDA; 0.5 ml/liter of 92% lactic acid) for 7 days incubation at 20°C. Fifteen light gray to gray colonies with aerial mycelia and showing alternating growth rings were subcultured in APDA. Abundant black pycnidia with cream-colored cirrhi were often present after 7 to 10 days at 20°C in APDA cultures. The conidia on the APDA were smooth, unicellular, hyaline, ellipsoid to lacriform with flattened ends, and (5.2) 6.6 (7.9) µm × (2.9) 3.6 (4.7) µm. Based on morphology, this fungus was identified as Phacidiopycnis washingtonensis Xiao & J.J Rogers (Xiao et al. 2005). Conidia of P. washingtonensis differ in size and shape with P. piris (Xiao et al. 2005). To confirm its identity, the internal transcribed spacer (ITS) region of rDNA of four isolates (Mz-1, Mz-4, Mz-5, and Mz-9, GenBank Accession Nos. KP759279 to KP759282, respectively) was amplified and sequenced using primer ITS4/ITS5. BLASTn analyses showed 99% identity with P. washingtonensis (ex-type, AY608644). To prove pathogenicity, 12 mature Pink Lady apple fruits were superficially disinfected using 75% ethanol for 30 s and injured with a sterile 5-mm diameter cork borer. Then, apple fruits were inoculated with 40 µl of conidial suspension (106 conidia/ml) of four isolates (Mz-1, Mz-4, Mz-5, and Mz-9). An equal number of fruits treated with 40 µl of sterile water were used as negative controls. The fruits were placed into commercial apple box and incubated at 20°C for 15 days. An additional 12 fruits were disinfested, wounded, and inoculated as described above, including negative controls; however, these fruits were placed in a cold chamber at 0°C for 35 days. All inoculated apple fruits developed necrotic lesions measuring 26.1 to 31.3 mm and 60.1 to 70.4 mm in diameter for 0 and 20°C storage conditions, respectively. The negative controls remained healthy. Reisolations were performed on APDA and the presence of P. washingtonensis was morphologically confirmed in 100% of the symptomatic fruits. To our knowledge, this study is the first report of P. washingtonensis causing speck rot on cold stored apple fruit in Chile and South America. The impact of speck rot on the Chilean apple industry is unknown, but we determined a 0.2 to 13.9% prevalence (n = 9,489 apple fruits) of speck rot on stored Pink Lady apples.References:Kim, Y. K., and Xiao, C. L. 2006. Plant Dis. 90:1376. https://doi.org/10.1094/PD-90-1376 Link, ISI, Google ScholarODEPA. Ministerio de Agricultura, Gobierno de Chile. www.odepa.cl, accessed 6 February 2015. Google ScholarWeber, R. W. S. 2011. J. Phytopathol. 159:682. https://doi.org/10.1111/j.1439-0434.2011.01826.x Crossref, ISI, Google ScholarXiao, C. L., et al. 2005. Mycologia 97:464. https://doi.org/10.3852/mycologia.97.2.464 Crossref, ISI, Google ScholarDetailsFiguresLiterature CitedRelated Vol. 100, No. 1 January 2016SubscribeISSN:0191-2917e-ISSN:1943-7692 Metrics Article History Issue Date: 15 Jan 2016Published: 25 Nov 2015First Look: 30 Jun 2015Accepted: 17 Jun 2015 Page: 211 Information© 2016 The American Phytopathological SocietyCited byPhacidiopycnis washingtonensisCABI Compendium, Vol. CABI CompendiumIdentification and characterization of isolates of Botrytis obtained from blossom blight and fruits with calyx-end rot in apples in ChileActa Horticulturae, No. 1325Identification and characterization of Diplodia mutila, D. seriata, Phacidiopycnis washingtonensis and Phacidium lacerum obtained from apple (Malus x domestica) fruit rot in Maule Region, Chile24 November 2018 | European Journal of Plant Pathology, Vol. 153, No. 4Sensitivity of Phacidiopycnis spp. Isolates from Pome Fruit to Six Pre- and Postharvest FungicidesEmran Md. Ali, Laxmi K. Pandit, Katie A. Mulvaney, and Achour Amiri12 January 2018 | Plant Disease, Vol. 102, No. 3Occurrence of Severe Outbreak of Calyx-End Rot Associated with Botrytis cinerea in Malus × domestica cv. Cripps Pink During Harvest in the Maule Region, ChileE. E. Ferrada, M. Lolas, C. Pacheco, and G. A. Díaz29 September 2017 | Plant Disease, Vol. 101, No. 12Notes for genera: Ascomycota14 October 2017 | Fungal Diversity, Vol. 86, No. 1

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