HomePlant DiseaseVol. 103, No. 3First Report of Curvularia intermedia Causing Leaf Blight on Annual Ryegrass (Lolium multiflorum) in China PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Curvularia intermedia Causing Leaf Blight on Annual Ryegrass (Lolium multiflorum) in ChinaJ. Li, M. Li, X. X. Gao, and F. FangJ. Lihttp://orcid.org/0000-0001-7473-753XDepartment of Weed Science, Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan 250100, China, M. Li†Corresponding author: M. Li; E-mail: E-mail Address: limei9909@163.comDepartment of Weed Science, Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan 250100, China, X. X. GaoDepartment of Weed Science, Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan 250100, China, and F. FangDepartment of Weed Science, Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan 250100, ChinaAffiliationsAuthors and Affiliations J. Li M. Li † X. X. Gao F. Fang Department of Weed Science, Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan 250100, China Published Online:21 Jan 2019https://doi.org/10.1094/PDIS-06-18-0955-PDNAboutSections ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat In China, there are approximately 6 million hectares planted with Lolium multiflorum, an important grass in grassland livestock production. A survey of 23 grasslands located across Shandong Province conducted in 2017 revealed that approximately 8% of L. multiflorum plants showed leaf blight symptoms. Most symptoms developed on the leaf margin and began as small, light gray spots. Spots gradually coalesced into larger, irregular lesions and eventually dried and formed extensive necrotic areas. Six samples were taken to the laboratory for isolation. For isolation, pieces were taken from margins of leaf spots, rinsed in water, surface disinfected (5% NaClO solution for 3 min and then 75% ethanol for 30 s), rinsed twice in sterilized distilled water, dried, placed on potato dextrose agar (PDA) medium, and incubated in darkness at 25°C until growth occurred. Newly formed aerial mycelia were transferred to a new PDA plate and incubated at 25°C (16-h photoperiod) for sporulation and morphological observations. Colonies were initially white and then gray-brown with flocculent aerial mycelia. Conidiophores were solitary or clustered, 78 to 135 µm long × 4 to 7 µm wide (n = 50), and conidia were obclavate to ellipsoid or spindle shaped, brown, and measured 27.3 to 40.9 µm long × 13.3 to 17.7 µm wide (n = 50) with three false dissepiments. These characteristics are consistent with the morphology of Curvularia isolates (Mandokhot et al. 1972). For molecular identification, DNA from aerial mycelia of single-spore isolates was extracted using a fungal genomic DNA isolation kit (Sangon, Shanghai, China), and the rDNA internal transcribed spacer was amplified with the primers ITS4/ITS5 (White et al. 1990). Recovered polymerase chain reaction products were sequenced and submitted to GenBank as accession number MH118553. BLAST analysis revealed 99 to 100% identity with previously reported sequences of Curvularia intermedia isolates (GenBank accession nos. KX611668.1, KU856621.1, and KU856625.1). Phylogenetic tree analysis, using ClustalX and MEGA 6.0 software with the neighbor-joining method, also placed the isolates in the clade of C. intermedia with 100% bootstrap support. The identified isolate was used to carry out pathogenicity testing. Plants (six replicates) were inoculated by spraying a conidial suspension (107 conidia/ml), and controls were treated with sterile water. All treatments were incubated in a humid growth environment during the first 48 h at 28°C and then transferred to the greenhouse (25°C, 12-h photoperiod) for observation. Symptomatic plants identical to those described above were observed in all inoculated replicates but not in controls. The same pathogen was reisolated from inoculated plants but not from controls. In China, leaf blight has potential to seriously impact the establishment and productivity of annual ryegrass. To our knowledge, this is the first report of C. intermedia causing leaf blight on L. multiflorum in China.References:Mandokhot, A. M., et al. 1972. Eur. J. Plant Pathol. 78:65. Google ScholarWhite, T. J., et al. 1990. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA. Crossref, Google ScholarFunding: Funding was provided by National Natural Science Foundation of China (grant no. 31701804) and National Key R&D Program of China (grant no. 2017YFD0201304-3).DetailsFiguresLiterature CitedRelated Vol. 103, No. 3 March 2019SubscribeISSN:0191-2917e-ISSN:1943-7692 Metrics Article History Issue Date: 6 Mar 2019Published: 21 Jan 2019Accepted: 9 Oct 2018 Page: 585 Information© 2019 The American Phytopathological SocietyFundingNational Natural Science Foundation of ChinaGrant/Award Number: 31701804National Key R&D Program of ChinaGrant/Award Number: 2017YFD0201304-3Cited byFungi causing leaf spot diseases in Lolium multiflorum in Brazil2 October 2021 | Mycological Progress, Vol. 20, No. 9Molecular phylogeny and morphology reveal three novel species of Curvularia (Pleosporales, Pleosporaceae) associated with cereal crops and weedy grass hosts16 April 2021 | Mycological Progress, Vol. 20, No. 4