First Report of Rhizopus oryzae Causing Rhizome Rot on Ginger in China

HomePlant DiseaseVol. 107, No. 1First Report of Rhizopus oryzae Causing Rhizome Rot on Ginger in China PreviousNext DISEASE NOTE OPENOpen Access licenseFirst Report of Rhizopus oryzae Causing Rhizome Rot on Ginger in ChinaXuli Gao, Cuiping Jin, Chaoxia Li, Weihua Zhang, Yihong Wang, Yun Geng, Min Zhang, and Yongteng LiXuli Gaohttps://orcid.org/0000-0001-9814-8342Vegetable Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, Shandong, ChinaSearch for more papers by this author, Cuiping JinShandong Academy for Environmental Planning, Jinan 250101, Shandong, ChinaSearch for more papers by this author, Chaoxia LiVegetable Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, Shandong, ChinaSearch for more papers by this author, Weihua ZhangVegetable Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, Shandong, ChinaSearch for more papers by this author, Yihong WangVegetable Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, Shandong, ChinaSearch for more papers by this author, Yun GengInstitute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan 250100, Shandong, ChinaSearch for more papers by this author, Min ZhangVegetable Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, Shandong, ChinaSearch for more papers by this author, and Yongteng Li†Corresponding author: Y. Li; E-mail Address: [email protected]Vegetable Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, Shandong, ChinaSearch for more papers by this authorAffiliationsAuthors and Affiliations Xuli Gao1 Cuiping Jin2 Chaoxia Li1 Weihua Zhang1 Yihong Wang1 Yun Geng3 Min Zhang1 Yongteng Li1 † 1Vegetable Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, Shandong, China 2Shandong Academy for Environmental Planning, Jinan 250101, Shandong, China 3Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan 250100, Shandong, China Published Online:20 Jan 2023https://doi.org/10.1094/PDIS-12-21-2630-PDNAboutSectionsView articlePDFSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat View articleGinger (Zingiber officinale Rosc.) is an herbal plant widely grown in China for its medicinal and culinary purposes. In July 2020, a new rhizome rot disease was observed on ginger in Laiwu, Shandong Province, China. The disease symptoms were observed on both aboveground and underground plant parts. The aboveground stems and leaves became withered and yellow, and water-soaked symptoms were observed on the collar region. The diseased rhizomes were poorly developed with brown lesions, and eventually they would rot, without offensive odors. Disease incidence was estimated at approximately 5% across the survey area. To isolate the pathogen, tissues from 30 rhizomes were cut from the border between diseased and healthy tissue, surface sterilized in 75% alcohol for 15 s, soaked in 0.1% mercuric chloride for 1 min, washed with sterile distilled water three times, and plated on potato dextrose agar (PDA) at 25°C for 2 to 3 days. Twenty-nine fungal isolates with similar morphological characteristics were obtained, and pure cultures were obtained using single-spore isolation. The colony of AQJ-1, a representative isolate, on PDA was cottony, fluffy, white, and beige in coloration on the reverse side at first, and subsequently many black sporangia were produced. The sporangia were black, subglobose, and 45.2 to 181.7 μm (n = 50) in diameter. The sporangiospores were unequal, globose or subglobose, and about 3.2 to 8.7 × 4.6 to 12.3 μm (n = 50) in diameter. For the molecular characterization, genomic DNA was extracted by a modified cetyltrimethylammonium bromide method (Niu et al. 2008). The internal transcribed spacer (ITS) region and translation elongation factor 1-alpha (EF-1α) gene were amplified using the primer pairs ITS1/ITS4 (White et al. 1990) and MEF10/MEF4 (Abe et al. 2007), respectively. The ITS and EF-1α sequences of isolate AQJ-1 were submitted to GenBank (MN606288 and MN735220, respectively). The BLASTn analysis of the sequences showed 99 to 100% similarity to the sequences of Rhizopus oryzae strain CBS 120.12 (MH854609 and AB281529, respectively). Therefore, based on morphological and molecular characteristics, isolate AQJ-1 was identified as R. oryzae. For pathogenicity tests, 30 ginger seedlings (Laiwu Big Ginger) were grown for 30 days in plastic pots and were then removed from the pots and the rhizomes washed in running tap water. The rhizomes of 15 ginger seedlings were attached to a 7-mm agar disk from a plate containing 2-day-old mycelium, and the other 15 seedlings were attached to an agar disk without mycelium as a control. Then the inoculated and control seedlings were planted in pots and were kept in separate chambers in a greenhouse at 25 ± 2°C. After 14 days, the same symptoms of rhizome rot were observed in all inoculated plants as previously described, and no symptoms were observed on the control plants. The pathogen was reisolated from symptomatic tissues and was identified as R. oryzae, which fulfilled Koch’s postulates. To our knowledge, this is the first report of R. oryzae causing rhizome rot on ginger in China. This disease may pose a potential threat to ginger production in China.The author(s) declare no conflict of interest.References:Abe, A., et al. 2007. Mycologia 99:714. https://doi.org/10.3852/mycologia.99.5.714 Crossref, ISI, Google ScholarNiu, C., et al. 2008. Afr. J. Biotechnol. 7:2818. 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 ScholarX. Gao and C. Jin contributed equally to this work.Funding: This research was supported by Shandong Province Key R&D Program (Major Science and Technology Innovation Project) (2021CXGC010802), National Natural Science Foundation of China (32102219, 32100016), China Agriculture Research System (CARS-23-G13), and Jinan Top Ten Agricultural Characteristic Producing (Laiwu Ginger) Scientific and Technological Innovation Team.The author(s) declare no conflict of interest.DetailsFiguresLiterature CitedRelated Vol. 107, No. 1 January 2023SubscribeISSN:0191-2917e-ISSN:1943-7692 Download Metrics Article History Issue Date: 1 Feb 2023Published: 20 Jan 2023First Look: 25 May 2022Accepted: 17 May 2022 Page: 231 Information© 2023 The American Phytopathological SocietyFundingShandong Province Key R&D Program (Major Science and Technology Innovation Project)Grant/Award Number: 2021CXGC010802National Natural Science Foundation of ChinaGrant/Award Number: 32102219Grant/Award Number: 32100016China Agriculture Research SystemGrant/Award Number: CARS-23-G13Jinan Top Ten Agricultural Characteristic Producing (Laiwu Ginger) Scientific and Technological Innovation TeamKeywordsgingerrhizome rotRhizopus oryzaeThe author(s) declare no conflict of interest.PDF download