First Report of Fusarium falciforme (FSSC 3+4) Causing Root Rot in Weigela florida in China

Field: Agricultural and Biological Sciences (Life Sciences)

HomePlant DiseaseVol. 104, No. 3First Report of Fusarium falciforme (FSSC 3+4) Causing Root Rot in Weigela florida in China PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Fusarium falciforme (FSSC 3+4) Causing Root Rot in Weigela florida in ChinaDong-Xia Shen, Zong-Wen Song, Yi-Ming Lu, and Ben FanDong-Xia ShenCo-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China, Zong-Wen SongCo-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China, Yi-Ming LuCo-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China, and Ben Fan†Corresponding author: B. Fan; E-mail Address: fanben2000@gmail.comhttp://orcid.org/0000-0001-8532-1281Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China AffiliationsAuthors and Affiliations Dong-Xia Shen Zong-Wen Song Yi-Ming Lu Ben Fan † Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China Published Online:20 Jan 2020https://doi.org/10.1094/PDIS-03-19-0521-PDNAboutSectionsSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Weigela florida is a deciduous shrub of Caprifoliaceae family in East Asia. Due to its exceptional flowers and long blooming period, W. florida has been cultivated in an expanding area in eastern China in recent years. In 2017, approximately 15% of 5-year-old W. florida plants grown in a nursery garden in Jurong County, Jiangsu Province, exhibited typical root rot symptoms. The young leaves gradually turned chlorotic until the entire plants wilted. Vascular tissue of the roots showed red-brown and necrosis symptoms with bast and xylem separated. White mycelia were noticed on some of the infected roots. Diseased crown root tissues (5 × 5 mm) were surface sterilized using 75% ethanol for 3 min followed by 10% sodium hypochlorite for 5 min before being rinsed with sterile water three times. The inner portion of the tissue was taken out with a sterile knife and incubated at 25°C for 3 days on PDA. A representative strain (FBF7) was isolated from the crown roots of a diseased plant. The aerial mycelium of FBF7 on PDA was fluffy and white in the first several days before gradually turning purple and red. Microconidia were mostly pear shaped and measured as 6.8 to 17.3 (average 11.5) × 2.2 to 5.7 (average 3.7) µm, and some macroconidia were falcate, with pointed apexes and one to three septa, with a size of 13.2 to 38.8 × 3.2 to 6.7 µm (n = 100). To further identify the pathogen, total DNA was extracted from the 5-day-old aerial mycelium grown on PDA. The translation elongation factor (TEF1-α), internal transcribed spacer (ITS), and RNA polymerase II subunit 2 (RPB2) genes were amplified by PCR and sequenced (Liu et al. 1999; O'Donnell et al. 1998; Sung et al. 2007; White et al. 1990). All sequencing results were deposited in GenBank with accession numbers MK317963 (ITS), MK606409 (TEF1-α), and MK606410 (RPB2). The TEF1-α and RBP2 sequences showed 99.84 and 99.76% homology to Fusarium solani species complex (FSSC) 3+4-c NRRL43536 in Fusarium ID, respectively. Maximum likelihood analysis was carried out using sequences of the ITS, TEF1-α, and RBP2 genes from Fusarium sp. and other species from the FSSC. Phylogenetic analysis revealed a distinct clade close to Fusarium falciforme (FSSC 3+4a) and rooted to F. staphyleae (Chitrampalam et al. 2016; O'Donnell et al. 2008). The pathogenicity test was performed with 6-month-old healthy W. florida plants as follows. Conidia prepared by incubating for 3 days in Czapek medium at 25°C with shaking at 200 rpm were suspended (106 CFU/ml) and inoculated to the rhizosphere of nine young plants grown in flowerpots (15 cm in diameter). Another group of nine young plants without inoculation served as the control. All plants were kept at 25°C and 65% relative humidity in a greenhouse. The leaves started to shrivel up about 25 days after inoculation and withered quickly in the next few days. Fibrous roots became darkened and began to decay on all the inoculated plants. Morphological and molecular identification of the reisolated pathogen was identical to the inoculated F. falciforme. The results showed that FBF7 can cause root rot of W. florida. Although F. falciforme is a clinically common species, recent studies revealed that it can also infect different plants, such as lima bean, onion basal, and soybean (Chitrampalam et al. 2016; Sousa et al. 2017; Tirado-Ramírez et al. 2018). To the best of our knowledge, this is the first report of F. falciforme causing root rot in W. florida in China. The pathogen may pose a significant threat to the W. florida industry in East China.The author(s) declare no conflict of interest.References:Chitrampalam, P., et al. 2016. Anton Leeuw Int J G. 109:335. https://doi.org/10.1007/s10482-015-0636-7 Crossref, ISI, Google ScholarLiu, Y. J., et al. 1999. Mol. Biol. Evol. 16:1799. https://doi.org/10.1093/oxfordjournals.molbev.a026092 Crossref, ISI, Google ScholarO'Donnell, K., et al. 1998. 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Song contributed equally to this work.The author(s) declare no conflict of interest.Funding: Funding was provided by National Natural Science Foundation of China (No. 31970097), the Key Program for Natural Science of the Higher Education Institutions in Jiangsu Province (17KJA220001), and Agricultural Technology R&D Program of Jurong (NY2017095974).DetailsFiguresLiterature CitedRelated Vol. 104, No. 3 March 2020SubscribeISSN:0191-2917e-ISSN:1943-7692 DownloadCaptionPathogenicity of Lasiodiploidia pseudotheobromae in a coffee plant 3 days after inoculation (R. L. Freitas-Lopes et al.). Photo credit: U. P. Lopes. Seedling blight of soybean caused by soilborne pathogens (J. R. Lamichhane et al.). Photo credit: M. I. Chilvers. Metrics Downloaded 1,134 times Article History Issue Date: 3 Mar 2020Published: 20 Jan 2020First Look: 20 Nov 2019Accepted: 10 Nov 2019 Pages: 981-981 Information© 2020 The American Phytopathological SocietyFundingNational Natural Science Foundation of ChinaGrant/Award Number: No. 31970097Key Program for Natural Science of the Higher Education Institutions in Jiangsu ProvinceGrant/Award Number: 17KJA220001Agricultural Technology R&D Program of JurongGrant/Award Number: NY2017095974Keywordsroot rot diseaseWeigela floridaFusarium falciformeThe author(s) declare no conflict of interest.