Abstract
Cucumber (Cucumis sativus L.) is a nutritious domesticated vegetable which belongs to Cucurbitaceae family. India ranks 30th in global cucumber production and its total output is 1,61,000 metric tons annually. In the investigation a different kind of leaf spot disease was observed on 2 months old cucumber leaves samples from cucumber fields in Baruipur, West Bengal, India (Latitude: N 22° 22.262′, Longitude: E 88° 24.5086′). The spots appeared were large, greyish brown in colour surrounded by a yellow to brownish halo, measuring 2 × 1 cm in average. These lesions expanded gradually from circular to angular spots ultimately resulting in necrosis and defoliation. The isolated fungus showed greyish black to dark olive mycelial growth. Microscopic characterization revealed straight to slightly curved conidia and distoseptate with a distinctly protruding basal hilum. Through microscopic observation and ITS sequencing the organism was identified to be Exserohilum rostratum. E. rostratum was previously known for causing blight disease in maize as well as human immune system diseases. E. rostratum, E. longirostratum and E. mcginnisii are identified as human pathogens. Koch’s postulates were carried out and distinct symptoms were observed in cucumber. As because there is no such record, this is the first time the host pathogen combination is separated in India.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Adler A, Yaniv I, Samra Z, Yacobovich J, Fisher S, Avrahami G, Levy I (2006) Exserohilum: an emerging human pathogen. Eur J Clin Microbiol Infect Dis 25(4):247–253. https://doi.org/10.1007/s10096-006-0093-3
Ahmadpour A, Karami S, Heidarian Z, Javan-Nikkhah M (2013) Exserohilum rostratum causing sugarcane leaf spot in Iran. Aust Plant Dis Notes 8(1):97–99. https://doi.org/10.1007/s13314-013-0105-y
Bashir KA, Kamaruzaman S, Khairulmazmi A (2018) First report of northern corn leaf blight disease caused by Exserohilum turcicum on Zea mays in Malaysia. J Mol Genet Med 12(4):387. https://doi.org/10.4172/1747-0862.1000387
Brunings AM, Datnoff LE, Palmateer AJ, Locke JC, Krause CR (2009) Exserohilum leaf spot on tiger grass. Plant Health Progress. https://doi.org/10.1094/PHP-2009-1215-01-RS
Bunkoed W, Kasam S, Chaijuckam P, Yhamsoongnern J, Prathuangwong S (2014) Sexual reproduction of Setosphaeria turcica in natural corn fields in Thailand. Kasetsart J (Nat Sci) 48:175–182
Chaidaroon W, Phaocharoen N, Srisomboon T, Vanittanakom N (2019) Exserohilum rostratum keratitis in a patient with human immunodeficiency virus. Case Rep Ophthalmol 10:127–133. https://doi.org/10.1159/000499688
Choudhary M, Sardana HR, Bhat MN, Gurjar MS (2018) First report of leaf spot disease caused by Exserohilum rostratum on bottle gourd in India. Plant Dis 102(10):2042. https://doi.org/10.1094/PDIS-02-18-0315-PDN
Guindon S, Dufayard JF, Lefort V, Anisimova M, Hordijk W, Gascuel O (2010) New algorithms and methods to estimate maximum-likelihood phylogenies: assessing the performance of PhyML 3.0. Syst Biol 59:307–321. https://doi.org/10.1093/sysbio/syq010
Hernández-Restrepo M, Madrid H, Tan YP, Da Cunha KC, Gené J, Guarro J, Crous PW (2018) Multi-locus phylogeny and taxonomy of Exserohilum. Persoonia - Molecular Phylogeny and Evolution of Fungi 41(38):71–108. https://doi.org/10.3767/persoonia.2018.41.05
Jones AM, Dodd ME, Webb AK (2001) Burkholderia cepacia: current clinical issues, environmental controversies and ethical dilemma. Eur Respir J 17(2):295–301
Jorgensen JH, Pfaller MA, Carroll KC, Funke G, Landry ML, Richter SS et al. (Eds.) (2015) Manual of clinical microbiology (11th ed.), ASM Press, Washington DC, pp. 1253–1273
Joseph NM, Kumar MA, Stephen S, Kumar S (2012) Keratomycosis caused by Exserohilum rostratum. Indian J Pathol Microbiol 55:248–249
Junier T, Zdobnov EM (2010) The Newick utilities: high-throughput phylogenetic tree processing in the UNIX shell. Bioinformatics 26:1669–1670. https://doi.org/10.1093/bioinformatics/btq243
Kadir JB, Ahmad A, Sariah M, Juraimi AS (2007) Fungal pathogen of Rottboellia cochinchinensis and its potential as bioherbicide. Asian J Plant Sci 6(1):21–28. https://doi.org/10.3923/ajps.2007.21.28
Katoh K, Standley DM (2013) MAFFT multiple sequence alignment software version 7: improvements in performance and usability. Mol Biol Evol 30:772–780. https://doi.org/10.1093/molbev/mst010
Katragkou A, Pana ZD, Perlin DS, Kontoyiannis DP, Walsh TJ, Roilides E (2014) Exserohilum infections: review of 48 cases before the 2012 United States outbreak. Med Mycol 52(4):376–386. https://doi.org/10.1093/mmy/myt030
Krishnan S, Manavathu EK, Chandrasekar PH (2009) Aspergillus flavus: an emerging non-fumigatus Aspergillus species of significance. Mycoses 52(3):206–222. https://doi.org/10.1111/j.1439-0507.2008.01642.x
Lefort V, Longueville JE, Gascuel O (2017) SMS: smart model selection in PhyML. Mol Biol Evol 34:2422–2424. https://doi.org/10.1093/molbev/msx149
Lemoine F, Domelevo Entfellner JB, Wilkinson E, Correia D, Dávila Felipe M, De Oliveira T, Gascuel O (2018) Renewing Felsenstein’s phylogenetic bootstrap in the era of big data. Nature 556:452–456. https://doi.org/10.1038/s41586-018-0043-0
Letunic I, Bork P (2019) Interactive tree of life(iTOL) v4: recent updates and new developments. Nucleic Acids Res 47(W1):W256–W259. https://doi.org/10.1093/nar/gkz239
Levy Y (1995) Inoculum survival of Exserohilum turcicum on corn between and during growing periods. Can J Plant Pathol 17:144–146
Luo ZW, He F, Fan HY, Wang XH, Hua M, Hu FC, Li XH, Liu ZX, Yu NT (2012) First report of leaf spot disease caused by Exserohilum rostratum on pineapple in Hainan Province, China. Plant Dis 96(3):458. https://doi.org/10.1094/PDIS-11-11-0979
MacFaddin JF (1985) Media for the isolation-cultivation-identification-maintenance of medical bacteria. Williams and Wilkins, Baltimore
Marcet-Houben M, Gabaldón T (2009) Acquisition of prokaryotic genes by fungal genomes. Trends Genet 26(1):5–8. https://doi.org/10.1016/j.tig.2009.11.007
Murray PR, Baron EJ, Jorgensen JH, Pfaller MA, Yolken RH (2003) Manual of clinical microbiology, Washington, D.C.: ASM Press, 8
Navaud O, Barbacci A, Taylor A, Clarkson JP, Raffaele S (2018) Shifts in diversification rates and host jump frequencies shaped the diversity of host range among Sclerotiniaceae fungal plant pathogens. Mol Ecol 27(5):1309–1323. https://doi.org/10.1111/mec.14523
Nwanosike MRO, Mabagala RB (2017) Influence of metrological parameters on the development of Exserohilum turcicum (Pass.) Leonard and Suggs on maize in Tanzania. International Journal of Agricultural and Food Research [IJAFR] 6(3):1–9
Shan-Hai L, Huang SL, Li Q, Hu CJ, Fu G, Qin L, Ma Y, Xie LZ, Cen Z, Yan W (2011) Characterization of Exserohilum rostratum, a new causal agent of banana leaf spot disease in China. Australas Plant Pathol 40(3):246–259. https://doi.org/10.1007/s13313-011-0037-y
Talavera G, Castresana J (2007) Improvement of phylogenies after removing divergent and ambiguously aligned blocks from protein sequence alignments. Syst Biol 56:564–577. https://doi.org/10.1080/10635150701472164
Toher ASM, Ahmad ZAM, Wong MY (2016) First report of Exserohilum rostratum as pathogen of rice brown spot in Malaysia. Plant Dis 100(1):226. https://doi.org/10.1094/PDIS-03-15-0276-PDN
Tsukamoto H, Gohbara M, Tsuda M, Fujimori T (1997) Evaluation of fungal pathogens as biological control agents for the paddy weed, Echinochloa species by drop inoculation. Jpn J Phytopathol 63(5):366–372. https://doi.org/10.3186/jjphytopath.63.366
Wang Y, Tian RM, Gao ZM, Bougouffa S, Qian P-Y (2014) Optimal eukaryotic 18S and universal 16S/18S ribosomal RNA primers and their application in a study of symbiosis. PLoS One 9(3):e90053. https://doi.org/10.1371/journal.pone.0090053
Zhang WM, Watson K (1997) Characterization of growth and conidia production of Exserohilum monoceras on different substrates. Biocontrol Sci Tech 7(1):75–86. https://doi.org/10.1080/09583159731063
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Dhara, B., Maity, A., Mondal, P. et al. First report of Exserohilum leaf spot: a unique halophilic pathogen in Cucumis sativus in the South Bengal area of India. Australasian Plant Pathol. 49, 257–266 (2020). https://doi.org/10.1007/s13313-020-00705-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s13313-020-00705-9