Diagnosis of Fungal Diseases of Plants

  • P. Narayanasamy


Crop plants are infected by numerous fungal pathogens from seedling stage to the seed maturing stage under the natural conditions, either singly or in combination with other kinds of microbial plant pathogens. Diagnosis of the ­disease problem observed for the first time, involves isolation of the fungi in pure cultures using appropriate media and identification of the putative pathogen based on ­morphological, physiological/biochemical, immunological and genomic nucleic acid characteristics, followed by inoculation onto the natural plant host for reproducing the symptoms observed earlier. The characteristics of the fungus reisolated from the inoculated plants are then compared with original description of the fungus isolated from the diseased plants earlier. Adoption of all steps in Koch’s postulates is essential. Precise identification of the pathogens up to subspecies, varieties, races/biotypes of the fungal pathogen species is accomplished by applying immunological and/or nucleic acid-based techniques. Correct diagnosis of the disease (s) is considered to be the corner stone of the development of effective management of the disease concerned. The need for establishing disease diagnostic centers and the role of plant quarantines in preventing the introduction of new plant diseases and principle of certification of seeds and propagative plant materials to reduce disease incidence and spread is highlighted.


Fungal Pathogen Downy Mildew Stripe Rust Botrytis Cinerea Host Plant Species 
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  1. Abang MM, Asiedu R, Hoffmann P, Wolf GA, Mignouna HD, Winter S (2005) Pathogenic and genetic variability among Colletotrichum gloeosporioides isolates from different yam hosts in the agroecological zones in Nigeria. J Phytopathol 153: 1–11.CrossRefGoogle Scholar
  2. Abang MM, Hoffmann P, Winter S, Green KR, Wolf GA (2004) Vegetative compatibility among isolates of Colletotrichum gloeosporioides from yam (Dioscorea spp.) in Nigeria. J Phytopathol 152: 21–27.CrossRefGoogle Scholar
  3. Beever RE, Weeds PL (2004) Taxonomy and genetic variation of Botrytis and Botryotina. In: Elad Y, Williamson P, Tudzinski P, Delen N (ed) Botrytis: Biology, Pathology and Control, Kluwer Academic, Dordrecht, pp. 29–52.Google Scholar
  4. Cadle-Davidson L (2008) Monitoring pathogenesis of natural Botrytis cinerea infections in developing grape berries. Amer J Enol Vitic 59: 387–395.Google Scholar
  5. Chilvers MI, du Toit LJ, Akamatsu H, Peever TL (2007) A real-time, quantitative PCR seed assay for Botrytis spp. that cause neck rot of onion. Plant Dis 91: 599–608.CrossRefGoogle Scholar
  6. Duffy BK, Weller DM (1994) A semi-selective and diagnostic medium for Gaeumannomyces graminis var. tritici. Phytopathology 84: 1407–1415.CrossRefGoogle Scholar
  7. Food and Agriculture Organization (FAO) (1991) Annex I: Quarantine Principles as Related to International Trade. Report of Expert Consultation on Harmonization of Plant Quarantine Principles, 6–10 May 1991, Food and Agriculture Organization, Rome, pp. 15–20.Google Scholar
  8. Ha Y, Fessehaie A, Ling KS, Wachter WP, Keinath AP, Walcott RR (2009) Simultaneous detection of Acidovorax avenae subs. Citrulli and Didymella bryoniae in cucurbit seed lots using magnetic capture hybridization and real-time polymerase chain reaction. Phytopathology 99: 666–678.PubMedCrossRefGoogle Scholar
  9. Ishii F, Fountaine J, Chung W-H, Kansako M, Nishimura K, Takahashi K, Oshima M (2009) Characterization of QoI-resistant field isolates of Botrytis cinerea from citrus and strawberry. Pest Manag Sci 65: 916–922.PubMedCrossRefGoogle Scholar
  10. Korolev N, Elad Y, Katan T (2008) Vegetative compatibility grouping in Botrytis cinerea using sulphate non-utilizing mutants. Eur J Plant Pathol 122: 369–383.CrossRefGoogle Scholar
  11. Meisel B, Korsman J, Kloppers FJ, Berger DK (2009) Cercospora zeina is the causal agent of grey leaf spot disease of maize in southern Africa. Eur J Plant Pathol 124: 577–583.CrossRefGoogle Scholar
  12. Narayanasamy P (2002) Microbial Plant Pathogens and Crop Disease Management. Science Publishers, Enfield, USA.Google Scholar
  13. Narayanasamy P (2006) Postharvest Pathogens and Disease Management. John Wiley & Sons, Hoboken, NJ, USA.Google Scholar
  14. Narayanasamy P (2008) Molecular Biology in Plant Pathogenesis and Disease Management, Volumes 1–3, Springer, Heidelberg, Germany.Google Scholar
  15. Romanazzi G, Murolo S, Pizzichini L, Nardi S (2009) Esca in young and mature vineyards and molecular diagnosis of the associated fungi. Eur J Plant Pathol 125: 277–290.CrossRefGoogle Scholar
  16. Stack J, Cardwell K, Hammerschmidt R, Byrne J, Loria R, Snover-Clift K, Baldwin W, Wisler G, Beck H, Bostock R, Thomas C, Luke E (2006) The national plant diagnostic network. Plant Dis 90: 128–136.CrossRefGoogle Scholar
  17. Wang X, Zheng W, Buchenauer H, Zhao J, Han Q, Huang L, Kang Z (2008) The development of a PCR based method for detecting Puccinia striiformis latent infections in wheat leaves. Eur J Plant Pathol 120: 241–247.CrossRefGoogle Scholar
  18. Yin Y, Ding L, Liu X, Yang J, Ma Z (2009) Detection of Sclerotinia sclerotiorum in planta by a real-time PCR assay. J Phytopathol 157: 465–469.CrossRefGoogle Scholar
  19. Yuan Q, Nian S, Yin Y, Li M, Cai J, Wang (2009) Development of a PCR-based diagnostic tool specific to wheat dwarf bunt caused by Tilletia controversa. Eur J Plant Pathol 124: 585–594.CrossRefGoogle Scholar

Copyright information

© Springer Netherlands 2011

Authors and Affiliations

  1. 1.CoimbatoreIndia

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