First Report of Stagonosporopsis caricae Causing Chayote Leaf Spot in Guizhou Province, China

HomePlant DiseaseVol. 107, No. 7First Report of Stagonosporopsis caricae Causing Chayote Leaf Spot in Guizhou Province, China PreviousNext DISEASE NOTE OPENOpen Access licenseFirst Report of Stagonosporopsis caricae Causing Chayote Leaf Spot in Guizhou Province, ChinaJun Zhang, Rui Yang, Shilong Jiang, Dongxue Li, Tao Li, Zhiying Yang, Jun Yuan, Yongtian Zhao, Xiaofeng Tan, Delu Wang, and Zhuo ChenJun ZhangKey Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, Guizhou 550025, China, Rui YangKey Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, Guizhou 550025, ChinaCollege of Agriculture, Guizhou University, Guiyang, Guizhou 550025, China, Shilong JiangKey Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, Guizhou 550025, ChinaCollege of Agriculture, Guizhou University, Guiyang, Guizhou 550025, China, Dongxue LiKey Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, Guizhou 550025, China, Tao LiKey Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, Guizhou 550025, ChinaCollege of Forestry, Guizhou University, Guiyang, Guizhou 550025, China, Zhiying YangKey Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, Guizhou 550025, ChinaCollege of Forestry, Guizhou University, Guiyang, Guizhou 550025, China, Jun YuanCollege of Agriculture, Guizhou University, Guiyang, Guizhou 550025, China, Yongtian ZhaoKey Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, Guizhou 550025, ChinaCollege of Life Science and Agriculture, Qiannan Normal University for Nationalities, Duyun, Guizhou 558000, China, Xiaofeng TanKey Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, Guizhou 550025, ChinaPlant Protection Station of Guizhou Province, Guiyang, Guizhou 550001, China, Delu Wang†Corresponding authors: D. L. Wang; E-mail Address: [email protected], and Z. Chen; E-mail Address: [email protected]Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, Guizhou 550025, ChinaCollege of Forestry, Guizhou University, Guiyang, Guizhou 550025, China, and Zhuo Chen†Corresponding authors: D. L. Wang; E-mail Address: [email protected], and Z. Chen; E-mail Address: [email protected]https://orcid.org/0000-0001-7130-8457Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, Guizhou 550025, ChinaAffiliationsAuthors and Affiliations Jun Zhang1 Rui Yang1 2 Shilong Jiang1 2 Dongxue Li1 Tao Li1 3 Zhiying Yang1 3 Jun Yuan2 Yongtian Zhao1 4 Xiaofeng Tan1 5 Delu Wang1 3 † Zhuo Chen1 † 1Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, Guizhou 550025, China 2College of Agriculture, Guizhou University, Guiyang, Guizhou 550025, China 3College of Forestry, Guizhou University, Guiyang, Guizhou 550025, China 4College of Life Science and Agriculture, Qiannan Normal University for Nationalities, Duyun, Guizhou 558000, China 5Plant Protection Station of Guizhou Province, Guiyang, Guizhou 550001, China Published Online:30 Jun 2023https://doi.org/10.1094/PDIS-07-22-1703-PDNAboutSectionsView articlePDFSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat View articleAt present, chayote (Sechium edule [Jacq.] Swartz) has been widely planted in Guizhou Province, southwestern China, and the cultivation area in Huishui County ranks first among all the counties or cities in Guizhou Province. Chayote leaf spot was first observed in Huishui County (25.99°N, 106.64°E) from April to June in 2019. The disease incidence was 52 to 58%, and the disease severity was 34 to 41% across nine chayote plantations. The disease caused huge production losses and reduced fruit quality. Leaf lesions initially occurred at the leaf margins, and the lesions expanded gradually, becoming dark brown and irregularly shaped. To identify the leaf spot-associated pathogen, the samples were cut from lesion margins, sterilized with 75% ethanol followed by 0.5% sodium hypochlorite for 30 s, rinsed with sterile water three times, and transferred onto potato dextrose agar (PDA). They were then incubated at 25°C in darkness for 5 days. The hyphal tips from the margins of growing colonies were successively transferred to fresh PDA plates for obtaining isolates. The representative strains with a similar morphology grew on PDA, malt extract agar (MEA), and oatmeal agar (OA) plates, and the colonies presented smooth margins and abundant mycelia on all three media. The colonies were gray to light green on PDA and gray on MEA and OA at 5 days postinoculation. At 11 days postinoculation on 10% V8 medium at 25°C with a cycle of 14 h/ultraviolet light and 10 h/night, a sexual morph was observed, ascomata pseudothecioid, subglobose, 121 × 142 μm, ostiolate, walls of brown textura angularis, smooth. Asci bitunicate, cylindrical to clavate, 7 × 90 μm, eight-spored, ascospores elliptical, straight to slightly curved, 5 × 17 μm, one-septate, constricted at the septum, subhyaline, smooth. An asexual morph was also observed. Conidiomata pycnidial, subglobose, 166 × 258 μm, ostiolate, wall of dark brown to black textura angularis, smooth. Conidia short, cylindrical or slightly reniform, 6.18 ± 0.67 × 3.51 ± 0.33 μm (n = 50), zero- to one-septate, hyaline, smooth. Chlamydospores were subhyaline to dark brown, verruculose or incidentally tuberculate, solitary or in chains, and 14.16 ± 1.23 × 5.92 ± 0.49 μm (n = 50). The morphological characteristics of the strains were identical to those of Stagonosporopsis caricae (Aveskamp et al. 2010; Sivanesan 1990). The genes or DNA sequences of the partial 28S large subunit rDNA, the internal transcribed spacer, RNA polymerase II second largest subunit, and beta-tubulin were amplified (Liu et al. 1999; Rehner and Samuels 1994; Sung et al. 2007; Vilgalys and Hester 1990; White et al. 1990; Woudenberg et al. 2009). The sequences were deposited in GenBank. A phylogenetic analysis confirmed these strains to be identical to S. caricae reference strains CBS 248.90, CBS 282.76, and PD 06/03082531. Pathogenicity tests were performed on potted chayote and 5-year-old chayote in the field. Mycelial plugs (6 mm diameter) were applied on wounded chayote leaves. Brown spots appeared on the wounded sites of chayote leaves after inoculation with mycelial plugs. No symptoms were observed on the leaves inoculated with PDA plugs lacking mycelia. The reisolated pathogen from diseased plants was identical to the representative strains used for inoculation. To our knowledge, this is the first report of S. caricae causing leaf spot on chayote in China, and our findings will be useful for its management and further research.The author(s) declare no conflict of interest.References:Aveskamp, M. M., et al. 2010. Stud. Mycol. 65:1. https://doi.org/10.3114/sim.2010.65.01 Crossref, ISI, Google ScholarLiu, Y. J., et al. 1999. Mol. Bio. Evol. 16:1799. https://doi.org/10.1093/oxfordjournals.molbev.a026092 Crossref, ISI, Google ScholarRehner, S. A., and Samuels, G. J. 1994. Mycol. Res. 98:625. https://doi.org/10.1016/S0953-7562(09)80409-7 Crossref, ISI, Google ScholarSivanesan, A. 1990. 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Persoonia 22:56. https://doi.org/10.3767/003158509X427808 Crossref, ISI, Google ScholarFunding: This work was supported by the Postsubsidy project of the National Key Research Development Program of China (2018-5262), the National Natural Science Foundation of China (no. 21977023, no. 31860515), the China Agriculture Research System of MOF and MARA (CARS-23-C07), and the Program of Introducing Talents to Chinese Universities (D20023).The author(s) declare no conflict of interest.DetailsFiguresLiterature CitedRelated Vol. 107, No. 7 July 2023SubscribeISSN:0191-2917e-ISSN:1943-7692 Download Metrics Article History Issue Date: 26 Jul 2023 Published: 30 Jun 2023 First Look: 19 Nov 2022 Accepted: 17 Nov 2022 Page: 2228 Information© 2023 The American Phytopathological SocietyFundingNational Key Research Development Program of ChinaGrant/Award Number: 2018-5262National Natural Science Foundation of ChinaGrant/Award Number: 21977023Grant/Award Number: 31860515China Agriculture Research System of MOF and MARAGrant/Award Number: CARS-23-C07Program of Introducing Talents to Chinese UniversitiesGrant/Award Number: D20023Keywordsfield cropsfungipathogen detectionThe author(s) declare no conflict of interest.PDF downloadCited byNew Species of Didymellaceae within Aquatic Plants from Southwestern China19 July 2023 | Journal of Fungi, Vol. 9, No. 7