First Report of Puccinia glechomatis, a Rust Fungus of Creeping Charlie, in Minnesota

HomePlant DiseaseVol. 107, No. 9First Report of Puccinia glechomatis, a Rust Fungus of Creeping Charlie, in Minnesota PreviousNext DISEASE NOTE OPENOpen Access licenseFirst Report of Puccinia glechomatis, a Rust Fungus of Creeping Charlie, in MinnesotaNicholas Greatens, Nick Klejeski, Les J. Szabo, Yue Jin, and Pablo D. Olivera FirpoNicholas Greatenshttps://orcid.org/0000-0003-2408-8871University of Minnesota Twin Cities Department of Plant Pathology, St. Paul, MNSearch for more papers by this author, Nick KlejeskiUniversity of Minnesota Twin Cities Department of Plant Pathology, St. Paul, MNSearch for more papers by this author, Les J. Szabohttps://orcid.org/0000-0002-0477-7808University of Minnesota Twin Cities Department of Plant Pathology, St. Paul, MNUSDA-ARS Cereal Disease Laboratory, St. Paul, MNSearch for more papers by this author, Yue JinUniversity of Minnesota Twin Cities Department of Plant Pathology, St. Paul, MNUSDA-ARS Cereal Disease Laboratory, St. Paul, MNSearch for more papers by this author, and Pablo D. Olivera Firpo†Corresponding author: P. D. Olivera Firpo; E-mail Address: [email protected]https://orcid.org/0000-0002-7867-0763University of Minnesota Twin Cities Department of Plant Pathology, St. Paul, MNSearch for more papers by this authorAffiliationsAuthors and Affiliations Nicholas Greatens1 Nick Klejeski1 Les J. Szabo1, 2 Yue Jin1, 2 Pablo D. Olivera Firpo1 † 1University of Minnesota Twin Cities Department of Plant Pathology, St. Paul, MN 2USDA-ARS Cereal Disease Laboratory, St. Paul, MN Published Online:11 Sep 2023https://doi.org/10.1094/PDIS-10-22-2315-PDNAboutSectionsView articlePDFSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat View articleIn 2020 and 2021, at four locations around the Twin Cities, Minnesota (Sept. 2021: 44.980°N, 93.319°W; Aug. 2021: 44.989°N, 93.186°W; Sept. 2020: 45.000°N, 93.138°W; Sept. 2020: 44.870°N, 92.779°W), a rust fungus was observed infecting creeping Charlie (Glechoma hederacea), a weed of Eurasian origin (Hutchings and Price 1999). Within stands, severity ranged from 1 to 30% leaf loss. Telia were reddish brown when young, starting small (0.1 to 0.5 mm) and growing into round but irregular sori measuring 1 to 5 mm, sometimes coalescing to form larger sori. Sori were primarily abaxial, forming depressions on the adaxial surface and sometimes occurring along stems and leaf petioles. Partial leaf necrosis occurred with high foliar infection and leaf dieback with high infection of petioles. Thin-walled, colorless leptosporic teliospores, or leptospores, were present in samples. Dark, thick-walled teliospores were not noted. Leaves bearing leptospores were soaked in water for 4 h and suspended over young plants in a dew chamber at 20°C for 16 h. Plants were maintained in a greenhouse at 20 to 22°C. After 3 weeks, nascent telia were observed on inoculated plants. The ITS region and a segment of EF1-α were selected for sequencing for the samples from the first two listed locations. For the ITS region, the primers ITS1rustF10d (Barnes and Szabo 2007) and ITSRu1 (Rioux et al. 2015) were used, and for EF1-α, a reaction was conducted as described by van der Merwe et al. (2007). Amplicons were barcoded and sequenced on Oxford Nanopore MinION by following manufacturer instructions (kits EXP-PBC001 and SQK-LSK109 with R9 flow cells). Reads (PRJNA802185) were filtered for quality (>Q16), sorted and separated by length, and aligned. A consensus sequence was generated for each amplicon with >50× coverage. BLAST searches of the EF1-α sequences OM489402 and OM489403 from the first two locations, respectively, showed 99.3% (643/647) and 99.7% (645/647) similarity with Puccinia glechomatis (EF560587). ITS sequences had not been reported for P. glechomatis, and there are no matches with >96% homology in GenBank for the sequence OM470970 or OM470969 from the same samples. Morphological and life cycle traits are consistent with this identification. Creeping Charlie is a common weed of turf, gardens, orchards, forests, and meadows. It is present in 46 of the lower 48 United States but is most common east of the Great Plains, in the Pacific Northwest, and in neighboring regions of southern Canada (Böllmann and Scholler 2004). P. glechomatis was recorded for the first time in 1992 in north-central Pennsylvania (Böllmann and Scholler 2006). Examination of herbarium specimens and surveys established its distribution across the eastern United States and in a small area in the Pacific Northwest by the early 2000s, and in 2001 its presence was recorded in southern Wisconsin (Böllmann and Scholler 2006). The basidiospores likely do not travel far, but the fungus may move long distances through plant matter and establish in new locations (Böllmann and Scholler 2006). P. glechomatis is not known to affect native plants and may have a positive ecological effect, reducing the vigor of its undesirable host. To our knowledge, this is the first report of P. glechomatis in Minnesota. It is evidence of the continued westward spread of this rust in North America (Böllmann and Scholler 2006). Sequenced samples were submitted to the Arthur Fungarium at Purdue University (PUR N24012 and PUR N24013).The author(s) declare no conflict of interest.References:Barnes, C. W., and Szabo, L. J. 2007. Phytopathology 97:717. https://doi.org/10.1094/PHYTO-97-6-0717 Link, ISI, Google ScholarBöllmann, J., and Scholler, M. 2004. Feddes Repert. 115:178. https://doi.org/10.1002/fedr.200311035 Crossref, Google ScholarBöllmann, J., and Scholler, M. 2006. Mycoscience 47:152. https://doi.org/10.1007/s10267-006-0282-z Crossref, Google ScholarHutchings, M. J., and Price, E. A. C. 1999. J. Ecol. 87:347. https://doi.org/10.1046/j.1365-2745.1999.00358.x Crossref, ISI, Google ScholarRioux, S., et al. 2015. Phytoprotection 95:7. https://doi.org/10.7202/1028400ar Crossref, ISI, Google Scholarvan der Merwe, M., et al. 2007. Mycol. Res. 111:163. https://doi.org/10.1016/j.mycres.2006.09.015 Crossref, ISI, Google ScholarFunding: Funding was provided by the Minnesota Invasive Terrestrial Plants and Pests Center (grant number CON000000067760 - 00064801).The author(s) declare no conflict of interest.DetailsFiguresLiterature CitedRelated Vol. 107, No. 9 September 2023SubscribeISSN:0191-2917e-ISSN:1943-7692 Download Metrics Article History Issue Date: 29 Sep 2023Published: 11 Sep 2023First Look: 1 Mar 2023Accepted: 22 Feb 2023 Page: 2877 Information© 2023 The American Phytopathological SocietyFundingMinnesota Invasive Terrestrial Plants and Pests CenterGrant/Award Number: CON000000067760 - 00064801KeywordsfungiGlechoma hederaceaMinnesotapathogen detectionPuccinia glechomatisThe author(s) declare no conflict of interest.PDF download