Calophoma clematidina Causing Leaf Spot and Wilt on Clematis Plants in the Czech Republic

HomePlant DiseaseVol. 107, No. 6Calophoma clematidina Causing Leaf Spot and Wilt on Clematis Plants in the Czech Republic PreviousNext DISEASE NOTE OPENOpen Access licenseCalophoma clematidina Causing Leaf Spot and Wilt on Clematis Plants in the Czech RepublicM. Špetík, A. Eichmeier, J. Burgová, J. Z. Groenewald, and P. W. CrousM. Špetík†Corresponding author: M. Špetík; E-mail Address: [email protected]https://orcid.org/0000-0001-7659-8852Mendeleum – Institute of Genetics, Faculty of Horticulture, Mendel University in Brno, 691 44, Lednice na Moravě, Czech RepublicSearch for more papers by this author, A. Eichmeierhttps://orcid.org/0000-0001-7358-3903Mendeleum – Institute of Genetics, Faculty of Horticulture, Mendel University in Brno, 691 44, Lednice na Moravě, Czech RepublicSearch for more papers by this author, J. BurgováDepartment of Breeding and Propagation of Horticultural Plants, Faculty of Horticulture, Mendel University in Brno, 691 44, Lednice na Moravě, Czech RepublicSearch for more papers by this author, J. Z. Groenewaldhttps://orcid.org/0000-0002-9474-6246Westerdijk Fungal Biodiversity Institute, 3584 CT, Utrecht, the NetherlandsSearch for more papers by this author, and P. W. CrousWesterdijk Fungal Biodiversity Institute, 3584 CT, Utrecht, the NetherlandsSearch for more papers by this authorAffiliationsAuthors and Affiliations M. Špetík1 † A. Eichmeier1 J. Burgová2 J. Z. Groenewald3 P. W. Crous3 1Mendeleum – Institute of Genetics, Faculty of Horticulture, Mendel University in Brno, 691 44, Lednice na Moravě, Czech Republic 2Department of Breeding and Propagation of Horticultural Plants, Faculty of Horticulture, Mendel University in Brno, 691 44, Lednice na Moravě, Czech Republic 3Westerdijk Fungal Biodiversity Institute, 3584 CT, Utrecht, the Netherlands Published Online:14 Jun 2023https://doi.org/10.1094/PDIS-09-22-2142-PDNAboutSectionsView articlePDFSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat View articleClematis L. is one of the largest genera of Ranunculaceae, comprising over 300 plant species (Wang and Li 2005). They are mostly flowering creepers commonly grown as ornamentals. Clematis leaf spot and wilt is a fungal disease caused by Calophoma clematidina (Thüm.) Q. Chen & L. Cai. Infected plants initially show irregular brown to black leaf spots, which later turn into large necroses, usually leading to wilt disease. In June 2021, Clematis plants displaying symptoms described above were observed in three independent nurseries located in three counties (Brno-venkov, Břeclav, and Nymburk) in the Czech Republic. Around 60% of 120 inspected plants were symptomatic, including both mother plants and young plants. Leaves, stems, and roots of 43 diseased plants originating from the three nurseries were collected, sectioned into small pieces (5 × 5 mm), surface sterilized (60 s in 75% ethanol followed by 60 s in 1% sodium hypochlorite and rinsed three times using sterile distilled water), plated on potato dextrose agar (PDA), and incubated at 25°C for 5 weeks. Newly developed mycelia were immediately transferred to fresh PDA plates and purified by single-spore isolation. A total of 21 strains morphologically resembled the genus Calophoma. Colonies on PDA (7 days at 25°C) were felty, white to olivaceous/iron grey in the center. Conidiomata were dark brown, pycnidial, solitary or in groups (117 to 220 × 65 to 170 μm). Conidia were cylindrical to ellipsoidal, hyaline, 0 (–1)-septate (4 to 8 × 2 to 3 μm). Two representative isolates were deposited at the Westerdijk Fungal Biodiversity Institute, Utrecht, the Netherlands (CBS 149230 and CBS 149231). The partial internal transcribed spacer (ITS) regions, large ribosomal subunit of the nrRNA gene (LSU), beta-tubulin gene (tub2), and RNA polymerase II second largest subunit gene (rpb2) were amplified from genomic DNA of both isolates following protocols previously described (Spetik et al. 2022). Sequences were deposited in NCBI GenBank (accession nos.: ITS, ON107539, ON107540; LSU, ON108575, ON108576; tub2, ON314832, ON314833; rpb2, ON125007, ON125008), being 100% identical with that of the ex-type strain of C. clematidina (CBS 108.79), ITS (NR_135964), LSU (FJ515632), tub2 (FJ427100), and rpb2 (KT389588). Phylogenetically, the two representative isolates formed a fully supported clade with sequences of the ex-type and another culture of C. clematidina in the multigene phylogeny. To confirm Koch’s postulates, leaves of ten 2-month-old Clematis plants grown in pots were wounded by a needle and inoculated with a conidial suspension (1.0 × 106 conidia/ml) of both strains (five plants per strain) following the method of Golazar et al. (2011). Ten plants were mock inoculated with sterile distilled water and served as controls. Within 1 month, inoculated plants exhibited dark necrotic leaf spots similar to the symptoms observed in the nurseries, whereas controls remained symptomless. C. clematidina was reisolated from the inoculated plants and its identity confirmed (ITS, GenBank OP363927). The experiment was repeated. Although known from Europe, this is the first report of Clematis leaf spot and wilt caused by C. clematidina in the Czech Republic. Clematis leaf spot and wilt represents a serious disease in Czech nurseries, with the pathogen present in leaves, stems, and roots of Clematis spp.The author(s) declare no conflict of interest.References:Golzar, H., et al. 2011. Australas. Plant Dis. Notes 6:87. https://doi.org/10.1007/s13314-011-0030-x Crossref, Google ScholarSpetik, M., et al. 2022. Phytotaxa 559:238. https://doi.org/10.11646/phytotaxa.559.3.2 Crossref, ISI, Google ScholarWang, W. T., and Li, L. Q. 2005. Acta Phytotax. Sin. 43:431. https://doi.org/10.1360/aps040130 Google ScholarFunding: This work was supported by an internal grant from Mendel University in Brno (no. IGA-ZF/2021-ST2003) and Operační program Výzkum, vývoj a vzdělávání (CZ.02.1.01/0.0/0.0/16_017/0002334).The author(s) declare no conflict of interest.DetailsFiguresLiterature CitedRelated Vol. 107, No. 6 June 2023SubscribeISSN:0191-2917e-ISSN:1943-7692 Download Metrics Article History Issue Date: 26 Jun 2023Published: 14 Jun 2023First Look: 16 Nov 2022Accepted: 15 Nov 2022 Page: 1952 Information© 2023 The American Phytopathological SocietyFundingMendel University in BrnoGrant/Award Number: IGA-ZF/2021-ST2003Operační program Výzkum, vývoj a vzděláváníGrant/Award Number: CZ.02.1.01/0.0/0.0/16_017/0002334KeywordsCalophoma clematidinaClematisCzech Republicfungimolecular identificationnurseriesThe author(s) declare no conflict of interest.PDF download