First Report of Fusarium fujikuroi Causing Brown Leaf Spot on Kiwifruit

HomePlant DiseaseVol. 104, No. 5First Report of Fusarium fujikuroi Causing Brown Leaf Spot on Kiwifruit PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Fusarium fujikuroi Causing Brown Leaf Spot on KiwifruitHuanhuan Li, Wei Tang, Kui Liu, Lin Zhang, Xiaofeng Tang, Min Miao, and Yongsheng LiuHuanhuan Lihttp://orcid.org/0000-0001-5500-1017School of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, ChinaNorth Minzu University, Yinchuan 750021, ChinaSearch for more papers by this author, Wei TangSchool of Horticulture, Anhui Agricultural University, Hefei 230036, ChinaSearch for more papers by this author, Kui LiuSchool of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, ChinaSearch for more papers by this author, Lin ZhangSchool of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, ChinaSearch for more papers by this author, Xiaofeng TangSchool of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, ChinaSearch for more papers by this author, Min Miao†Corresponding authors: M. Miao; E-mail Address: minmiao@hfut.edu.cn and Y. Liu; E-mail Address: liuyongsheng1122@hfut.edu.cnSchool of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, ChinaSearch for more papers by this author, and Yongsheng Liu†Corresponding authors: M. Miao; E-mail Address: minmiao@hfut.edu.cn and Y. Liu; E-mail Address: liuyongsheng1122@hfut.edu.cnhttp://orcid.org/0000-0001-5686-4797School of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, ChinaSchool of Horticulture, Anhui Agricultural University, Hefei 230036, ChinaMinistry of Education Key Laboratory for Bio-resource and Eco-environment, College of Life Science, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610064, ChinaSearch for more papers by this author AffiliationsAuthors and Affiliations Huanhuan Li1 2 Wei Tang3 Kui Liu1 Lin Zhang1 Xiaofeng Tang1 Min Miao1 † Yongsheng Liu1 3 4 † 1School of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, China 2North Minzu University, Yinchuan 750021, China 3School of Horticulture, Anhui Agricultural University, Hefei 230036, China 4Ministry of Education Key Laboratory for Bio-resource and Eco-environment, College of Life Science, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610064, China Published Online:23 Feb 2020https://doi.org/10.1094/PDIS-10-19-2112-PDNAboutSectionsSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Kiwifruit (Actinidia spp.) is native to China, and kiwifruit brown leaf spot (BLS) disease has become more severe as planting area has increased. The disease persists throughout the growing season and causes serious defoliation and fruit drop, adversely affecting fruit yield and quality as well as economic returns. In June 2018, symptoms of BLS were observed on cv. Taishan No.1 (A. chinensis) in a farm in Shandong Province (118.5°E, 35.9°N) with a disease incidence of ∼60.0%. Symptomatic small spots initially appeared at the middle or edges of leaves, enlarged irregularly, and developed into brown necrotic spots with dying curly edges. The margins between symptomatic and healthy tissues (6 × 6 mm) were excised from three plants, surface disinfested in 1% NaOCl for 30 s and 70% ethanol solution for 45 s, washed, dried, plated on PDA containing 50 mg/liter of streptomycin sulfate in the dark, and incubated at 25°C for 3 days. Hyphal tips were transferred to PDA to obtain pure cultures. After 7 days, eight pure cultures were obtained, including seven previously reported Alternaria tenuissima, which is a major pathogen of kiwifruit BLS (Li et al. 2019) and one unknown isolate (LYL4). LYL4 formed colonies of ∼50 to 54 mm (diameter) at 25°C after 4 days on potato sucrose agar. Colonies developed abundant aerial mycelium that was initially white and fluffy and subsequently became purple with age. Colonies on PDA produced abundant conidia 2 weeks later. Microconidia were abundant, solitary, thin walled, hyaline, ovoid, 0 to 1 septate, and 1.6 to 3.2 × 4.3 to 11.7 µm. Macroconidia had a curved apical cell and foot-like basal cell with 3 to 5 septa and were 2.6 to 4.5 × 26.3 to 44.1 µm. Chlamydospores were absent. Conidiogenous cells were 14.6 to 23.3 µm long, bamboo shaped, thick walled, unbranched or rarely branched. Isolate LYL4 can form swollen cells. These morphological characteristics were consistent with Fusarium spp. (Leslie and Summerell 2006). To identify the species of LYL4, RNA polymerase II subunit 1 (RPB1) gene, RNA polymerase II largest subunit (RPB2) gene, and translation elongation factor-1 alpha regions (TEF-1α) were amplified using primers F5/G2R, 5F2/7CR (O’Donnell et al. 2010), and EF1-728F/EF1-986R (Zhou et al. 2015) and sequenced. BLAST analysis determined that LYL4 had 99.9% homology to F. fujikuroi Nirenberg strain NRRL13566 (JX171456.1) based on RPB1 gene sequences (MN207158), 99.7% to F. fujikuroi Nirenberg strain NRRL13566 (JX171570.1) based on RPB2 sequences (MN207159), and 100.0% to F. fujikuroi Nirenberg strain NRRL66440 (MH398220.1) based on the TEF-1α sequences (MN207157). Polyphasic identification by Fusarium MLST showed 99.8% identity with the F. fujikuroi Nirenberg strain NRRL13566. A phylogenetic tree was constructed using the maximum parsimony method (MEGA7) with a combined dataset of RPB1, RPB2, and TEF-1α sequences. Molecular phylogenetic analysis confirmed that LYL4 was F. fujikuroi. The pathogenicity of LYL4 was tested on the plants of cv. Jinyan (A. chinensis). Ten healthy unwounded plants were surface disinfected in 0.1% NaOCl for 20 s, washed, and dried. Five plants were sprayed with spore suspension (1 × 106 conidia/ml) and five with sterilized water as a control. Plants were incubated at 22°C (8 h dark)/25°C (16 h light) at 90% humidity. All plants inoculated with LYL4 produced the same symptoms as those observed in the field after 49 days treatment. BLS symptoms were not observed on control plants. The test was performed twice, and the fungi were reisolated and identified as F. fujikuroi based on morphology and TEF-1α analyses. In New Zealand, F. acuminatum Ellis & Everhart was reported to cause kiwifruit leaf spot (Hawthorne et al. 1986). In China, A. tenuissima (Li et al. 2019), Botryosphaeria dothidea, Lasiodiplodia theobromae, and Neofusicoccum parvum (Zhou et al. 2015) were reported as causal agents of BLS disease of kiwifruit foliage. This is the first report of F. fujikuroi causing BLS on kiwifruit worldwide.The author(s) declare no conflict of interest.References:Hawthorne, B. T., et al. 1986. New Zeal. J. Agric. Res. 29:533. Crossref, ISI, Google ScholarLeslie, J. F., and Summerell, B. A. 2006. Page 172 in: The Fusarium Laboratory Manual. Blackwell, Hoboken, NJ. https://doi.org/10.1002/9780470278376 Google ScholarLi, L., et al. 2019. Plant Dis. 103:582. https://doi.org/10.1094/PDIS-07-18-1217-PDN Link, ISI, Google ScholarO’Donnell, K., et al. 2010. J. Clin. Microbiol. 48:3708. https://doi.org/10.1128/JCM.00989-10 Crossref, ISI, Google ScholarZhou, Y., et al. 2015. Plant Dis. 99:699. https://doi.org/10.1094/PDIS-07-14-0727-RE Link, ISI, Google ScholarH. Li and W. Tang contributed equally to this work.The author(s) declare no conflict of interest.Funding: This study was supported by the National Natural Science Foundation of China (31972474, 31461143008, 31471157, and 31701059) and the Anhui Provincial Natural Science Foundation (1708085MC75).DetailsFiguresLiterature CitedRelated Vol. 104, No. 5 May 2020SubscribeISSN:0191-2917e-ISSN:1943-7692 DownloadCaptionSymptoms observed in the field on zucchini plants caused by Fusarium solani f. sp. cucurbitae (A. Pérez-Hernández et al.). Photo credit: J. M. Gómez-Vázquez. Peach tree with excavated root collar (S. B. Miller et al.). Photo credit: G. Schnabel. Metrics Downloaded 1,321 times Article History Issue Date: 3 May 2020Published: 23 Feb 2020First Look: 20 Dec 2019Accepted: 16 Dec 2019 Page: 1560 Information© 2020 The American Phytopathological SocietyFundingNational Natural Science Foundation of ChinaGrant/Award Number: 31972474Grant/Award Number: 31461143008Grant/Award Number: 31471157Grant/Award Number: 31701059Anhui Provincial Natural Science FoundationGrant/Award Number: 1708085MC75Keywordsfungipathogen detectionThe author(s) declare no conflict of interest.Cited ByFusarium species associated with leaf spots of mango in ChinaMicrobial Pathogenesis, Vol. 150