HomePlant DiseaseVol. 100, No. 7First Report of Anthracnose Caused by Colletotrichum spaethianum on Fragrant Plantain Lily in Korea PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Anthracnose Caused by Colletotrichum spaethianum on Fragrant Plantain Lily in KoreaW. Cheon and Y. JeonW. CheonSearch for more papers by this author and Y. JeonSearch for more papers by this authorAffiliationsAuthors and Affiliations W. Cheon Y. Jeon , Department of Bioresource Sciences, Andong National University, Andong 760-749, Korea. Published Online:28 Mar 2016https://doi.org/10.1094/PDIS-11-15-1341-PDNAboutSectionsSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat In autumn 2012, fragrant plantain lily (Hosta plantaginea Aschers) plants in Andong Region, Korea, were found to be showing leaf blight symptoms. Voucher specimens were deposited in the Herbarium of Mycology, Agricultural Science and Technology Research Institute, Andong National University, as Accession No. ANU-APEC0025F. Disease symptoms included brown necrotic lesions 30 to 100 mm in diameter. At the initial stage of the infection, lesions on the outer edge of the leaves were round to elliptical, and 5 to 15 mm in diameter. Gradually, the lesions became irregular, dark brown, and frequently surrounded by a pale yellow halo that later became necrotic and spread toward the petioles. Small sections (5 to 10 mm2) of diseased areas were excised from the margins of the lesions and placed on potato dextrose agar (PDA) after surface sterilization with 70% ethanol and 1% NaOCl for 1 min, and incubated for 3 days at 25°C. The fungus isolated using this procedure produced whitish mycelia when grown on PDA, and these mycelia later became gray to dark gray and produced tufts of aerial mycelia. Analysis of light micrographs showed that the fungus had falcate, hyaline, aseptate conidia 13.78 to 22.81 μm × 2.85 to 4.04 μm. These conidia were observed from both naturally infected leaves and PDA-cultured colonies. Appressoria were found either singly or in loose groups of dark brown, irregular shapes, and 6.3 to 11.1 × 5.3 to 7.7 μm. The acervular conidiomata were covered with abundant setae that were straight and dark brown, and 75.23 to 131.3 × 2.53 to 4.52 μm. The fungus was identified as Colletotrichum spaethianum on the basis of its morphology (Damm et al. 2009) and by sequence analysis of conserved ribosomal RNA (rRNA) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) sequences. Specifically, the rRNA internal transcribed spacer (ITS) region was amplified using a polymerase chain reaction (PCR) to form rDNA for in vitro sequencing using the primers ITS1 (forward) and ITS4 (reverse) with the GenBank Accession No. KU572437, and the GAPDH region was amplified using the GDF (forward) and GDR (reverse) primer set, as described previously (Templeton et al. 1992). Nucleotide BLAST analysis of the two PCR products showed 100% sequence similarity with the nucleotide sequences of C. spaethianum (GQ856747 and GU228200). In our study, the sequences of C. spaethianum were deposited as GenBank Accession Nos. KT321124 and KT321125. To confirm pathogenicity, H. plantaginea plants grown in greenhouse were inoculated by foliar spray with 2-week-old cultures grown on PDA. Control plants were sprayed with sterile water. Plants were covered with plastic bags for 72 h to maintain high relative humidity (∼80 to 90%) in a growth chamber (26°C). Seven days after inoculation, the small, circular, pale brown spots developed on pathogen-inoculated leaves, and gradually expanded, developing a yellow halo. Based on the observed symptoms, morphological characteristics, molecular data, and pathogenicity against the host plant, it can be concluded that C. spaethianum is the causal agent of anthracnose of H. plantaginea in Korea. Colletotrichum spaethianum was isolated from H. sieboldiana in Germany (White et al. 1990) a different species of the same genus. To our knowledge, this is the first documented report of C. spaethianum causing anthracnose on fragrant plantain lily in Korea.
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Dec 2, 2024
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