Research Article

Phenotypical and Molecular Characterization of Local Clavibacter michiganensis subsp. michiganensis, the Causal Agent of Tomato Bacterial Canker Disease

Volume: 9 Number: Special December 28, 2025

Phenotypical and Molecular Characterization of Local Clavibacter michiganensis subsp. michiganensis, the Causal Agent of Tomato Bacterial Canker Disease

Abstract

Clavibacter michiganensis subsp. michiganensis (Cmm) is a significant bacterial pathogen causing tomato wilt and canker, leading to substantial yield and quality losses in tomato production. This study aimed to characterize Cmm isolates phenotypically and molecularly, assess their genetic variation, and evaluate their pathogenicity. Phenotypic characterization involved biochemical tests, including Gram staining, fluorescence, levan formation, oxidase, pectolytic activity, arginine dehydrolase, tobacco hypersensitivity, gelatin, esculin, and starch hydrolysis, as well as carbon source utilization profiling. Molecular identification employed conventional PCR and qPCR using Cmm-specific primers Cmm5/Cmm6. Genetic variation was assessed using REP-PCR with REP, ERIC, and BOX elements. Results showed that all isolates were Gram-positive, non-fluorescent, and negative for levan formation, oxidase, pectolytic activity, and arginine dehydrolase. They induced a hypersensitive reaction in tobacco and hydrolyzed starch. Variations were observed in gelatin and esculin hydrolysis and carbon source utilization. PCR and qPCR confirmed the isolates as Cmm. REP-PCR revealed that the REP element was ineffective, the ERIC element discriminated only at the subspecies level, while the BOX element differentiated intraspecific genetic variation. Pathogenicity tests demonstrated varying degrees of virulence among isolates. The study highlights the reliability of molecular diagnostic methods and the correlation between genetic diversity and virulence in Cmm isolates, providing insights for developing specific markers to distinguish avirulent and hypervirulent strains.

Keywords

Tomato, Bacterial canker, Phenotypical characterization, Molecular characterization

Supporting Institution

This research was supported by the Ege University OYP Coordination Office

Thanks

The authors would like to thank the Ege University OYP Coordination Office for its financial support.

References

  1. Akat, S., & Özaktan, H. (2016). Domates bakteriyel kanser ve solgunluk hastalığıyla [Clavibacter michiganensis subsp. michiganensis (Smith) Davis et. al] biyolojik mücadelede bakteriyel antagonistlerin etkinliğinin araştırılması. Türkiye Biyolojik Mücadele Dergisi, 2(1), 3–18. https://dergipark.org.tr/tr/pub/tbmd/issue/22450/240172
  2. Alvarez, A., Jenkins, D., & Callahan, S. (2014). Establishment and validation of loop-mediated amplification for specific detection of tomato bacterial pathogen. https://search.proquest.com/openview/3a3b641ea432819de069f937187c4325/1?pq-origsite=gscholar&cbl=18750
  3. Anonymus. (2015). https://wiki.bugwood.org/Clavibacter_michiganensis_subsp._michiganensis
  4. Anonymus. (2022). Tarım ve Orman Bakanlığı, Bitkisel Üretim Genel Müdürlüğü Çiftçi Kayıt Sistemi Verileri.
  5. Basim, E., Basim, H., Dickstein, E. R., & Jones, J. B. (2004). Bacterial Canker Caused by Clavibacter michiganensis subsp. michiganensis on Greenhouse-Grown Tomato in the Western Mediterranean Region of Turkey. Plant Disease, 88(9), 1048–1048. https://doi.org/10.1094/pdis.2004.88.9.1048b
  6. Bergüzar, S. (2014). Tokat yöresinde domates bakteriyel solgunluk hastalığı etmeni (Clavibacter michiganensis subsp. michiganensis)’nin tanılanması ve epidemiyolojisi üzerine araştırmalar. Gaziosmanpaşa Üniversitesi.
  7. Bermpohl, A., Dreier, J., Bahro, R., & Eichenlaub, R. (1996). Exopolysaccharides in the pathogenic interaction of Clavibacter michiganensis subsp. michiganensis with tomato plants. Microbiological Research, 151(4), 391–399. https://doi.org/10.1016/S0944-5013(96)80009-7
  8. Bolaños-Carriel, C., Gallegos, P., Ochoa, J. B., Insuasti, M., Bonilla, V., Evans, M. H., Alvarez, J., Ramirez, D., & León-Reyes, A. (2017). Bacterial canker caused by Clavibacter michiganensis subsp. michiganensis in naranjilla in Ecuador. Biotecnología Vegetal, 17(4), 221–227. https://core.ac.uk/download/pdf/228605561.pdf
  9. Burokienė, D. (2006). Early detection of Clavibacter michiganensis subsp . Michiganensi in tomato seedlings. Agronomy Research, 4, 151–154. https://agronomy.emu.ee/wp-content/uploads/2006/10/p4S07.pdf
  10. CABI. (2021). Solanum lycopersicum (tomato). CABI Compendium. https://doi.org/10.1079/CABICOMPENDIUM.31837
APA
Şanver, U., & Özaktan, H. (2025). Phenotypical and Molecular Characterization of Local Clavibacter michiganensis subsp. michiganensis, the Causal Agent of Tomato Bacterial Canker Disease. International Journal of Agriculture Environment and Food Sciences, 9(Special), 181-191. https://doi.org/10.31015/2025.si.26
AMA
1.Şanver U, Özaktan H. Phenotypical and Molecular Characterization of Local Clavibacter michiganensis subsp. michiganensis, the Causal Agent of Tomato Bacterial Canker Disease. int. j. agric. environ. food sci. 2025;9(Special):181-191. doi:10.31015/2025.si.26
Chicago
Şanver, Utku, and Hatice Özaktan. 2025. “Phenotypical and Molecular Characterization of Local Clavibacter Michiganensis Subsp. Michiganensis, the Causal Agent of Tomato Bacterial Canker Disease”. International Journal of Agriculture Environment and Food Sciences 9 (Special): 181-91. https://doi.org/10.31015/2025.si.26.
EndNote
Şanver U, Özaktan H (December 1, 2025) Phenotypical and Molecular Characterization of Local Clavibacter michiganensis subsp. michiganensis, the Causal Agent of Tomato Bacterial Canker Disease. International Journal of Agriculture Environment and Food Sciences 9 Special 181–191.
IEEE
[1]U. Şanver and H. Özaktan, “Phenotypical and Molecular Characterization of Local Clavibacter michiganensis subsp. michiganensis, the Causal Agent of Tomato Bacterial Canker Disease”, int. j. agric. environ. food sci., vol. 9, no. Special, pp. 181–191, Dec. 2025, doi: 10.31015/2025.si.26.
ISNAD
Şanver, Utku - Özaktan, Hatice. “Phenotypical and Molecular Characterization of Local Clavibacter Michiganensis Subsp. Michiganensis, the Causal Agent of Tomato Bacterial Canker Disease”. International Journal of Agriculture Environment and Food Sciences 9/Special (December 1, 2025): 181-191. https://doi.org/10.31015/2025.si.26.
JAMA
1.Şanver U, Özaktan H. Phenotypical and Molecular Characterization of Local Clavibacter michiganensis subsp. michiganensis, the Causal Agent of Tomato Bacterial Canker Disease. int. j. agric. environ. food sci. 2025;9:181–191.
MLA
Şanver, Utku, and Hatice Özaktan. “Phenotypical and Molecular Characterization of Local Clavibacter Michiganensis Subsp. Michiganensis, the Causal Agent of Tomato Bacterial Canker Disease”. International Journal of Agriculture Environment and Food Sciences, vol. 9, no. Special, Dec. 2025, pp. 181-9, doi:10.31015/2025.si.26.
Vancouver
1.Utku Şanver, Hatice Özaktan. Phenotypical and Molecular Characterization of Local Clavibacter michiganensis subsp. michiganensis, the Causal Agent of Tomato Bacterial Canker Disease. int. j. agric. environ. food sci. 2025 Dec. 1;9(Special):181-9. doi:10.31015/2025.si.26