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First Report of Curvularia tuberculata Causing Brown Leaf Spot of Rice in Punjab, Pakistan

2016; American Phytopathological Society; Volume: 100; Issue: 8 Linguagem: Inglês

10.1094/pdis-02-16-0198-pdn

1943-7692

R. A. Majeed, Ahmad Ali Shahid, Muhammad Saleem, Muhammad Asif, Manzoor Ahmad Zahid, Muhammad Samee Haider,

Plant Disease Resistance and Genetics

HomePlant DiseaseVol. 100, No. 8First Report of Curvularia tuberculata Causing Brown Leaf Spot of Rice in Punjab, Pakistan PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Curvularia tuberculata Causing Brown Leaf Spot of Rice in Punjab, PakistanR. A. Majeed, A. A. Shahid, M. Z. Saleem, M. Asif, M. A. Zahid, and M. S. HaiderR. A. Majeed, A. A. Shahid, M. Z. Saleem, M. Asif, M. A. Zahid, and M. S. HaiderAffiliationsAuthors and Affiliations R. A. Majeed A. A. Shahid , Institute of Agricultural Sciences, University of the Punjab, New Campus, Lahore, Pakistan M. Z. Saleem , Center for Applied Molecular Biology, Lahore, Pakistan M. Asif M. A. Zahid M. S. Haider , Institute of Agricultural Sciences, University of the Punjab, New Campus, Lahore, Pakistan. Published Online:1 Jun 2016https://doi.org/10.1094/PDIS-02-16-0198-PDNAboutSections ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat A leaf spot of rice (Oryza sativa L.) was observed on different cvs. Super Basmati, Basmati 515, Basmati 385, and Supery in a survey conducted from August 2013 to October 2014 in six different districts of Punjab, Pakistan: Lahore, Sheikhupura, Hafizabad, Gujanwala, Narowal, and Sailkot. Symptoms appeared as brown spots on the leaf blade and on immature leaves. Primary symptoms were brown, small, ovoid spots with a chlorotic halo, evenly distributed over the leaf starting from margins toward the midrib. The size of spots varied from 9 mm to 2 cm. Over time, spots enlarged and coalesced. Infected leaves were collected and washed with water for 5 to 10 min. Small pieces (0.5 to 2 cm) of leaf tissue were then surface disinfected with 2% NaOCl for 2 min, rinsed three to four times in sterile distilled water (SDW), blotted dry on sterile filter paper, and placed on potato dextrose agar (PDA). PDA cultures were incubated at 28°C for 5 to 7 days. On PDA, fungal colonies were zonate and felted with a grayish-black sporulation. The reverse side of the colonies was zonate, black at the center, and grayish toward the edges. Microscopically, the fungal hyphae were branched, septate, subhyaline to dark brown, and smooth walled. Conidiophores were dark brown, septate, unbranched, and genticulated. Conidia were of light to dark brown, straight, but sometimes curved, measuring 17 to 38.5 × 12.5 to 14.0 μm with 3 to 5 septa. The conidia were borne at the tip, arranged in a whorl. Pure cultures were submitted to Frist Fungal Culture Bank of Pakistan (FCBP) for further identification. The identity of the isolated fungus was accomplished by seqeuncing the rDNA ITS region (da Cunha et al. 2013) using ITS1 and ITS4 primers. An NCBI-BLASTn search results showed greatest homology (99% similarity) with sequences of Curvularia tuberculata (GenBank Accession No. KJ767096 and HF934907). The sequence was deposited in GenBank (KR704891). Based on microscopic, morphological, and molecular characteristics, the fungal isolates were identified as C. tuberculata (Wakker) Boedijin (Ellis 1971). Pathogenicity was confirmed by following Koch's postulates. Greenhouse-grown rice plants cv. Super Basmati and Basmati 515 were inoculated at the two leaf stage with a conidial suspension (104 spores/ml) prepared in SDW with a hand sprayer and then covered with plastic bags for 24 h. Control plants were sprayed with SDW and covered with plastic bags. Plants were incubated at 28°C for 1 week in greenhouse. Disease severity on inoculated leaves was estimated 7 days after inoculation using a 0 to 5 severity scale. Symptoms identical to those observed in the survey were observed on all the inoculated leaves after 1 week, whereas no symptoms appeared on the control plants. The pathogen reisolated from inoculated leaves confirming Koch's postulates. To the best of our knowledge, this is the first report of brown leaf spot caused by C. tuberculata on rice in Punjab, Pakistan, and represents a considerable threat to the Pakistani rice industry.References:da Cunha, K. C., et al. 2013. Diagn. Microbiol. Infect. Dis. 76:168. https://doi.org/10.1016/j.diagmicrobio.2013.02.034 Crossref, ISI, Google ScholarEllis, M. B. 1971. Dematiaceous Hyphomycetes. Commonwealth Mycological Institute, Kew, Surrey, U.K. Crossref, Google ScholarDetailsFiguresLiterature CitedRelated Vol. 100, No. 8 August 2016SubscribeISSN:0191-2917e-ISSN:1943-7692 Metrics Article History Issue Date: 22 Jul 2016Published: 1 Jun 2016First Look: 12 Apr 2016Accepted: 6 Apr 2016 Pages: 1791-1791 Information© 2016 The American Phytopathological SocietyCited byMorphological and Molecular Analysis of Fungal Species Associated with Blast and Brown Spot Diseases of Oryza sativaSuvanthini Terensan, H. Nishadi S. Fernando, J. Nilanthi Silva, S. A. Chandrika N. Perera, Nisha S. Kottearachchi, and O. V. D. S. Jagathpriya Weerasena5 May 2022 | Plant Disease, Vol. 106, No. 6Cochliobolus tuberculatus (leaf spot of Cyperus)CABI Compendium, Vol. CABI Compendium