Nigrospora sphaerica Causing Leaf Blight Disease on Sesame in Pakistan

HomePlant DiseaseVol. 106, No. 1Nigrospora sphaerica Causing Leaf Blight Disease on Sesame in Pakistan PreviousNext DISEASE NOTE OPENOpen Access licenseNigrospora sphaerica Causing Leaf Blight Disease on Sesame in PakistanA. Rehman, M. W. Alam, M. Saira, S. Naz, R. Mushtaq, T. A. Chohan, S. U. Din, A. Noureen, K. Gilani, and D. HussainA. RehmanDepartment of Plant Pathology, University of Agriculture, Faisalabad 38040, PakistanSearch for more papers by this author, M. W. Alam†Corresponding author: M. W. Alam; E-mail Address: [email protected]https://orcid.org/0000-0001-6072-0112Department of Plant Pathology, University of Agriculture, Faisalabad 38040, PakistanDepartment of Plant Pathology, University of Okara, PakistanSearch for more papers by this author, M. SairaPlant Pathology Research Institute, Ayub Agricultural Research Institute Faisalabad, 38000, Punjab, PakistanSearch for more papers by this author, S. Nazhttps://orcid.org/0000-0003-0868-6142Plant Pathology Research Institute, Ayub Agricultural Research Institute Faisalabad, 38000, Punjab, PakistanSearch for more papers by this author, R. Mushtaqhttps://orcid.org/0000-0002-9231-4546Institute of Molecular Biology and Biotechnology, The University of Lahore, PakistanSearch for more papers by this author, T. A. ChohanInstitute of Molecular Biology and Biotechnology, The University of Lahore, PakistanSearch for more papers by this author, S. U. DinInstitute of Molecular Biology and Biotechnology, The University of Lahore, PakistanSearch for more papers by this author, A. NoureenInstitute of Molecular Biology and Biotechnology, The University of Lahore, PakistanSearch for more papers by this author, K. GilaniInstitute of Molecular Biology and Biotechnology, The University of Lahore, PakistanSearch for more papers by this author, and D. HussainInstitute of Molecular Biology and Biotechnology, The University of Lahore, PakistanSearch for more papers by this authorAffiliationsAuthors and Affiliations A. Rehman1 M. W. Alam1 2 † M. Saira3 S. Naz3 R. Mushtaq4 T. A. Chohan4 S. U. Din4 A. Noureen4 K. Gilani4 D. Hussain4 1Department of Plant Pathology, University of Agriculture, Faisalabad 38040, Pakistan 2Department of Plant Pathology, University of Okara, Pakistan 3Plant Pathology Research Institute, Ayub Agricultural Research Institute Faisalabad, 38000, Punjab, Pakistan 4Institute of Molecular Biology and Biotechnology, The University of Lahore, Pakistan Published Online:8 Jan 2022https://doi.org/10.1094/PDIS-03-21-0460-PDNAboutSectionsPDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Sesame (Sesamum indicum L.) commonly known as “til”, is the most ancient and widely grown oilseed crop of Pakistan. During 2020, a field survey conducted in various research fields of Faisalabad (31°26′00.2″N, 73°04′25.4″E) revealed the occurrence of characteristic leaf blight disease with an incidence of 10 to 13%. The symptoms were characterized by yellow-brown and irregular lesions. At later stages, the lesions expanded and the affected leaves turned grayish to dark-brown and finally became wilted. Symptomatic leaves (both the diseased and healthy tissue) were cut into approximately 2 × 2-mm pieces, surface sterilized with 1% sodium hypochlorite for 30 s followed by 70% ethanol for 30 s, rinsed three times in sterile distilled water prior to culturing on potato dextrose agar (PDA), and incubated at 25°C under a 12-h photoperiod for 7 days. To obtain pure cultures, hyphal tips of growing mycelia from leaf tissues were carefully isolated and transferred onto fresh PDA plates. Fungal colonies of 11 isolates were initially white, becoming light to dark gray. The conidia were black, spherical to subspherical, single-celled, 12 to 14 × 18 to 20 μm in diameter, and borne on a hyaline vesicle at the tip of the conidiophore. Further, to identify the pathogen to the species level, genomic DNA was extracted using a modified CTAB protocol described by Guo et al. (2000). The internal transcribed spacer (ITS) region of the ribosomal DNA and translation elongation factor 1-alpha (TEF1-α) gene were amplified using ITS1/ITS4 (White et al. 1990) and EF1-728F/EF1-986R primer sets (Carbone and Kohn 1999), respectively. The sequences were submitted to GenBank (accession nos. MW287214 for ITS and MW325222 for TEF1-α). Sequence comparison revealed 99 and 100% similarity to multiple sequences of Nigrospora sphaerica (GenBank accessions KX834822 and MN995332). On the basis of cultural features, conidial morphology, and molecular data, the fungus was identified as N. sphaerica (Sacc.) Mason (Chen et al. 2018; Wang et al. 2017). To test the pathogenicity, fresh and healthy leaves of ten 6-week-old growth stage sesame plants were spray inoculated with a conidial suspension (105 conidia/ml) collected from a 7-day-old culture on PDA. In addition, 10 plants sprayed with sterile distilled water served as controls. Inoculated plants were covered with polyethylene bags to maintain high humidity and kept at 28°C, and observations were made at regular intervals. After 8 to 10 days of inoculation, leaves developed blight symptoms similar to those observed on naturally infected leaves, whereas control leaves remained asymptomatic. The pathogen was reisolated from the inoculated leaves, and its identity was confirmed by morphological and molecular (ITS and TEF1-α) means, thus fulfilling Koch’s postulates. N. sphaerica is distributed on a wide range of hosts and has been reported from different host genera including monocotyledonous and dicotyledonous ones (Wang et al. 2017). Previously, N. sphaerica has been reported to cause leaf blight of Cunninghamia lanceolata in China (Xu and Liu 2016). To the best of our knowledge, this is the first report of N. sphaerica as the causal agent of leaf blight of sesame in Pakistan. Because sesame is an important oilseed crop of Pakistan, appropriate disease management practices should be developed and implemented.The author(s) declare no conflict of interest.References:Carbone, I., and Kohn, L. M. 1999. Mycologia 91:553. https://doi.org/10.1080/00275514.1999.12061051 Crossref, ISI, Google ScholarChen, J., et al. 2018. Plant Dis. 102:245. https://doi.org/10.1094/PDIS-06-17-0914-PDN Link, ISI, Google ScholarGuo, L. D., et al. 2000. New Phytol. 147:617. https://doi.org/10.1046/j.1469-8137.2000.00716.x Crossref, ISI, Google ScholarWang, M., et al. 2017. Persoonia 39:118. https://doi.org/10.3767/persoonia.2017.39.06 Crossref, ISI, Google ScholarWhite, T. J., et al. 1990. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA. Google ScholarXu, Y. M., and Liu, Y. J. 2016. Plant Dis. 102:389. Google ScholarThe author(s) declare no conflict of interest.DetailsFiguresLiterature CitedRelated Vol. 106, No. 1 January 2022SubscribeISSN:0191-2917e-ISSN:1943-7692 DownloadCaptionSymptoms of Macrophomina phaseolina in melon (R. Cohen et al.). Photo credit: R. Cohen. Jute plant infected with papaya ring spot virus (PRSV) (sample MG16-004) (C. Biswas et al.). Photo credit: V. Ramesh Babu. Metrics Article History Issue Date: 7 Feb 2022Published: 8 Jan 2022First Look: 2 Aug 2021Accepted: 1 Aug 2021 Page: 317 Information© 2022 The American Phytopathological SocietyKeywordsfungioilseeds and legumesfield cropspathogen detectionThe author(s) declare no conflict of interest.PDF downloadCited byInhibitory action of ginkgolic acid against pathogenic fungi and characterisation of its inhibitory activities on Nigrospora oryzae17 February 2023 | Folia Horticulturae, Vol. 0, No. 0Plant Growth Promotion and Biocontrol of Leaf Blight Caused by Nigrospora sphaerica on Passion Fruit by Endophytic Bacillus subtilis Strain GUCC418 January 2023 | Journal of Fungi, Vol. 9, No. 2Occurrence of Nigrospora sphaerica causing leaf blight on Chrysanthemum morifolium in ChinaCrop Protection, Vol. 157