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First Report of Powdery Mildew Caused by Erysiphe polygoni on Homalocladium platycladum in Korea

2016; American Phytopathological Society; Volume: 100; Issue: 10 Linguagem: Inglês

10.1094/pdis-04-16-0539-pdn

1943-7692

Gab-Soo Han, Byung–Sup Kim, In‐Young Choi, S. E. Cho, Hyeon‐Dong Shin,

Plant Pathogens and Resistance

HomePlant DiseaseVol. 100, No. 10First Report of Powdery Mildew Caused by Erysiphe polygoni on Homalocladium platycladum in Korea PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Powdery Mildew Caused by Erysiphe polygoni on Homalocladium platycladum in KoreaG. S. Han, B. S. Kim, I. Y. Choi, S. E. Cho, and H. D. ShinG. S. HanSearch for more papers by this author, B. S. KimSearch for more papers by this author, I. Y. ChoiSearch for more papers by this author, S. E. ChoSearch for more papers by this author, and H. D. ShinSearch for more papers by this authorAffiliationsAuthors and Affiliations G. S. Han , Department of Environmental Landscape Architecture, Gangneung-Wonju National University, Gangneung 25457, Korea B. S. Kim , Department of Plant Science, Gangneung-Wonju National University, Gangneung 25457, Korea I. Y. Choi , Jeollabuk-do Agricultural Research and Extension Services, Iksan 54591, Korea S. E. Cho H. D. Shin , Division of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Korea. Published Online:8 Aug 2016https://doi.org/10.1094/PDIS-04-16-0539-PDNAboutSectionsSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Homalocladium platycladum (F. Muell. ex Hook.) L.H. Bailey [syn. Muehlenbeckia platyclada (F. Muell.) Meisn.], commonly known as centipede plant or ribbonbush, is a plant in the Polygonaceae from New Guinea and the Solomon Islands. In Korea, this plant is grown in greenhouses for ornamental purposes. In October 2015, several plants were found damaged by a powdery mildew in a greenhouse in Gongju (36°26′ N; 127°14′ E), Korea. In January 2016, powdery mildew symptoms were found on H. platycladum plants grown in a greenhouse in Seocheon (35°01′ N; 126°43′ E), Korea. Symptoms first appeared as thin white patches on the upper surface of leaves, which progressed to abundant hyphal growth on the both side of the leaves. Infected leaves, especially infected when young, often turned yellow or chlorotic with twisted margins and resulted in early defoliation. Voucher specimens were deposited in the Korea University Herbarium (KUS-F19990, F29116, F29129). Hyphal appressoria were well-developed, lobed, and solitary or in opposite pairs. Conidiophores were cylindrical, 70 to 160 × 7.5 to 9.0 µm, and composed of 3 to 4 cells. Foot-cells of conidiophores were straight, cylindric, and 25 to 40 µm long. Singly produced conidia were cylindric-oval to oblong, 30 to 47 × 15 to 25 µm with a length/width ratio of 1.3 to 2.3, with angular/rectangular wrinkling of outer walls, and devoid of distinct fibrosin bodies. Germ tubes were produced in the perihilar position of conidia. No chasmothecia were found. These structures are typical of the powdery mildew Pseudoidium anamorph of the genus Erysiphe. The measurements and host range match with those of E. polygoni DC. (Braun and Cook 2012). The complete internal transcribed spacer (ITS) regions of KUS-F29116 were amplified with primers ITS5/P3 and sequenced (Takamatsu et al. 2009). The resulting 558 bp sequence was deposited in GenBank (accession no. KX098506). The ITS sequence showed >99% sequence identity with the sequences of E. polygoni on Polygonum spp. (LC010013, AB104522, AF011307, etc.). Pathogenicity was confirmed through inoculation by dusting conidia onto leaves of five healthy potted H. platycladum. Five noninoculated plants served as controls. Inoculated plants were isolated from noninoculated plants in separate rooms in a greenhouse maintained at 26 to 30°C. Inoculated plants developed symptoms after 6 days, whereas the controls remained symptomless. The fungus present on the inoculated plants was identical morphologically to that originally observed on diseased plants, fulfilling Koch’s postulates. Association of H. platycladum with E. polygoni has been known in the United States, Europe (United Kingdom, Czech Republic, Romania, Finland, and former Soviet Union), and Asia (China, Taiwan, Nepal, and India) (Lebeda et al. 2007; Farr and Rossman 2016). To our knowledge, this is the first report of powdery mildew caused by E. polygoni on H. platycladum in Korea. Our observations in two greenhouses showed that this powdery mildew expanded rapidly on young leaves and detracted from the aesthetic value of plants.References:Braun, U., and Cook, R. T. A. 2012. Taxonomic Manual of the Erysiphales (Powdery Mildews), CBS Biodiversity Series No. 11. CBS, Utrecht, Netherlands. Google ScholarFarr, D. F., and Rossman, A. Y. 2016. Fungal Databases, Syst. Mycol. Microbiol. Lab., Online publication. ARS, USDA. Retrieved Apr. 22, 2016. Google ScholarLebeda, A., et al. 2007. Plant Pathol. 56:722. https://doi.org/10.1111/j.1365-3059.2007.01594.x Crossref, ISI, Google ScholarTakamatsu, S., et al. 2009. Mycol. Res. 113:117. https://doi.org/10.1016/j.mycres.2008.09.006 Crossref, Google ScholarDetailsFiguresLiterature CitedRelated Vol. 100, No. 10 October 2016SubscribeISSN:0191-2917e-ISSN:1943-7692 Metrics Article History Issue Date: 26 Sep 2016Published: 8 Aug 2016First Look: 1 Jun 2016Accepted: 23 May 2016 Pages: 2170-2170 Information© 2016 The American Phytopathological SocietyCited byErysiphe betae (sugarbeet powdery mildew)CABI Compendium, Vol. CABI Compendium