Root Rot Caused by Setophoma terrestris on Illicium verum in Yunnan Province, China

HomePlant DiseaseVol. 107, No. 8Root Rot Caused by Setophoma terrestris on Illicium verum in Yunnan Province, China PreviousNext DISEASE NOTE OPENOpen Access licenseRoot Rot Caused by Setophoma terrestris on Illicium verum in Yunnan Province, ChinaFengying Luo, Mei Huang, Han Liu, Shuying Li, Tianhui Zhu, Shan Han, Tiantian Lin, Adjei Mark Owusu, Youzhong Chen, and Shujiang LiFengying Luohttps://orcid.org/0000-0003-2095-7662College of Forestry, Sichuan Agricultural University, Chengdu, Sichuan Province 611130, ChinaSearch for more papers by this author, Mei HuangCollege of Forestry, Sichuan Agricultural University, Chengdu, Sichuan Province 611130, ChinaSearch for more papers by this author, Han LiuGanzi Institute of Forestry Research, Kangding, Sichuan Province 626001, ChinaSearch for more papers by this author, Shuying LiCollege of Forestry, Sichuan Agricultural University, Chengdu, Sichuan Province 611130, ChinaNational Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River and Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province, Chengdu, Sichuan Province 611130, ChinaSearch for more papers by this author, Tianhui Zhuhttps://orcid.org/0000-0002-1082-5175College of Forestry, Sichuan Agricultural University, Chengdu, Sichuan Province 611130, ChinaSearch for more papers by this author, Shan Hanhttps://orcid.org/0000-0002-4355-7808College of Forestry, Sichuan Agricultural University, Chengdu, Sichuan Province 611130, ChinaSearch for more papers by this author, Tiantian LinCollege of Forestry, Sichuan Agricultural University, Chengdu, Sichuan Province 611130, ChinaSearch for more papers by this author, Adjei Mark OwusuCollege of Forestry, Sichuan Agricultural University, Chengdu, Sichuan Province 611130, ChinaSearch for more papers by this author, Youzhong ChenSichuan Guoguang Agrochemical Co., Ltd., Chengdu 611130, ChinaSearch for more papers by this author, and Shujiang Li†Corresponding author: S. J. Li; E-mail Address: [email protected]https://orcid.org/0000-0003-3328-5332College of Forestry, Sichuan Agricultural University, Chengdu, Sichuan Province 611130, ChinaNational Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River and Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province, Chengdu, Sichuan Province 611130, ChinaSearch for more papers by this authorAffiliationsAuthors and Affiliations Fengying Luo1 Mei Huang1 Han Liu2 Shuying Li1 3 Tianhui Zhu1 Shan Han1 Tiantian Lin1 Adjei Mark Owusu1 Youzhong Chen4 Shujiang Li1 3 † 1College of Forestry, Sichuan Agricultural University, Chengdu, Sichuan Province 611130, China 2Ganzi Institute of Forestry Research, Kangding, Sichuan Province 626001, China 3National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River and Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province, Chengdu, Sichuan Province 611130, China 4Sichuan Guoguang Agrochemical Co., Ltd., Chengdu 611130, China Published Online:3 Aug 2023https://doi.org/10.1094/PDIS-01-23-0048-PDNAboutSectionsView articlePDFSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat View articleStar anise (Illicium verum Hook. f.), belonging to the family Magnoliaceae, is an important cash crop of “medicinal and food” origin, mainly from China. In August 2021, root rot of I. verum was first observed on more than 80% of the plants grown within a 500-ha area in Wenshan City, Yunnan Province. At the early stage of the disease, the phloem of the root was dark yellow-brown, and the leaves turned yellow. With further disease development, the whole root became black, and the leaves gradually fell off, affecting the growth and yield and eventually causing death of the whole plant. A total of 20 root samples were collected from typical symptomatic plants of 20 years old in Wenshan City (23°18′12″N, 103°57′38″E) and were cut into 2 × 2-mm pieces at the junction of infected and healthy tissue. Each sample was surface sterilized with 3% NaClO and 75% alcohol for 60 s before rinsing three times with distilled water. A sterile filter paper (5 × 5 cm) was used to dry the tissue, and the samples were cultured on potato dextrose agar amended with streptomycin sulfate (50 μg/ml). Plates were incubated at 25°C in the dark in an incubator. Out of nine isolates obtained in culture, seven exhibited the morphology described by Boerema et al. (2004) for Setophoma sp. Hyphae were hyaline and septate. After 14 days of culture on V8 juice agar, white round colonies were formed, but there was no groove in the middle of the colonies. Conidia were transparent, oval or cylindrical, and 6.0 to 8.0 × 2.5 to 4.0 μm. DNA was extracted from the representative isolate BJGF-04 for molecular identification using a fungal genomic DNA extraction kit (Solarbio, Beijing, China). Polymerase chain reaction (PCR) was performed with the primers ITS1/ITS4 for the internal transcribed spacer (ITS) region (White et al. 1990), T1/β-Sandy-R for the β-tubulin gene (TUB) region (Yang et al. 2017), NL3/LR5 for the 28S large subunit rDNA (LSU) region (Hu et al. 2021), and NS1/NS4 for the 5.8S large subunit rDNA (SSU) region (Mahesha et al. 2021). Newly generated representative sequences were deposited in GenBank (ITS, ON645256; TUB, ON854484; LSU, ON644445; SSU, ON644451). PCR products were sequenced and blasted, showing 99 to 100% sequence homology with Setophoma terrestris. Pathogenicity was performed using 1-year-old asymptomatic plants of I. verum. A conidial suspension (1 × 106 conidia/ml) collected from V8 juice cultures with 0.05% Tween buffer was poured at a volume of 10 ml per plant. Three individual seedlings were used as replicates for each treatment, and sterile water was used as the negative control. All plants were placed in an artificial climate incubator at 25°C under 90% relative humidity. After 20 days, all inoculated plants showed symptoms identical to those described above, whereas the controls remained healthy. S. terrestris was reisolated from the infected roots, which was confirmed by morphological and molecular identification, fulfilling Koch’s postulates. To our knowledge, this is the first report of S. terrestris as a causal agent of root rot on I. verum in China.The author(s) declare no conflict of interest.References:Boerema, G. H., et al. 2004. Phoma Identification Manual: Differentiation of Specific and Infra-Specific Taxa in Culture. CABI Publishing, Wallingford, U.K. https://doi.org/10.1079/9780851997438.0000 Crossref, Google ScholarHu, Z. Z., et al. 2021. Chin. J. Trop. Crops 42:488. https://doi.org/10.3969/j.issn.1000-2561.2021.02.026 Google ScholarMahesha, H. S., et al. 2021. Plant Dis. 105:1208. https://doi.org/10.1094/PDIS-04-20-0709-PDN Link, ISI, 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 ScholarYang, Y., et al. 2017. Anim. Reprod. Sci. 39:354. https://doi.org/10.1080/07060661.2017.1355849 Google ScholarF. Y. Luo and M. Huang contributed equally to this work.Funding: Funding was provided by the Research Interest Training Program for College Students (2023170), National Natural Science Foundation of China (32171795), and Sichuan Natural Science Foundation for Distinguished Young Scholar (2023NSFSC1936).The author(s) declare no conflict of interest.DetailsFiguresLiterature CitedRelated Vol. 107, No. 8 August 2023SubscribeISSN:0191-2917e-ISSN:1943-7692 Download Metrics Article History Issue Date: 29 Aug 2023Published: 3 Aug 2023First Look: 30 Mar 2023Accepted: 27 Mar 2023 Page: 2518 Information© 2023 The American Phytopathological SocietyFundingResearch Interest Training Program for College StudentsGrant/Award Number: 2023170National Natural Science Foundation of ChinaGrant/Award Number: 32171795Sichuan Natural Science Foundation for Distinguished Young ScholarGrant/Award Number: 2023NSFSC1936KeywordsIllicium verumroot rotSetophoma terrestrisThe author(s) declare no conflict of interest.PDF download