European Journal of Plant Pathology

, Volume 125, Issue 1, pp 87–95 | Cite as

Resistance to metalaxyl-M and cymoxanil in a dominant clonal lineage of Phytophthora infestans in Huánuco, Peru, an area of continuous potato production



Fifty-eight isolates of Phytophthora infestans were evaluated in vitro and on detached leaves of potato for their sensitivities to metalaxyl-M and cymoxanil. The isolates belonged to the clonal lineage, EC-1, which is dominant on potato in Peru and Ecuador. All isolates were collected in Huánuco, Peru, an area of year-round potato production, where the potential for development of fungicide resistance is high. All isolates were resistant to metalaxyl-M, with in vitro EC50 values ranging from 468.30—813.57 mg l−1. In contrast, we found no evidence for resistance to cymoxanil for which in vitro EC50 values ranged from 0.03—1.11 mg l−1. Resistance to each fungicide was also evaluated for five isolates in a detached leaf assay in which the fungicide was sprayed on the leaf surface prior to inoculation. With metalaxyl-M, the range of EC50 values was 158.85—828.29 mg l−1, similar to that for the in vitro assay. For cymoxanil, EC50 values ranged from 1.41 to 2.31 mg l−1, which was higher than in the in vitro assay but still two orders of magnitude lower than the concentration applied by farmers in the field.


Fungicide resistance Potato late blight Disease management EC50 



The authors wish to express their thanks Elvin De la Torre for technical support and Felipe De Mendiburu for assistance in statistical analysis.


  1. Adler, N. E., Erselius, L. J., Chacón, M. G., Flier, W. G., Ordoñez, M. E., Kroon, L. P. N. M., et al. (2004). Genetic diversity of Phytophthora infestans sensu lato in Ecuador provides new insight into the origin of this important plant pathogen. Phytopathology, 94, 154–162. doi:10.1094/PHYTO.2004.94.2.154.PubMedCrossRefGoogle Scholar
  2. Andrade-Piedra, J. L., Hijmans, R. J., Forbes, G. A., Fry, W. E., & Nelson, R. J. (2005). Simulation of potato late blight in the Andes: I: modification and parameterization of the LATEBLIGHT model. Phytopathology, 95, 1191–1199. doi:10.1094/PHYTO-95-1191.PubMedCrossRefGoogle Scholar
  3. Daayf, F., & Platt, H. (2002). Variability in responses of US-8 and US-11 genotypes of potato and tomato isolates of Phytophthora infestans to commercial fungicides in vitro. American Journal of Potato Research, 79, 433–441.CrossRefGoogle Scholar
  4. Davidse, L. C., Looijen, D., Turkensteen, L. J., & Van der Wal, D. (1981). Occurrence of metalaxyl-resistant strains of Phytophthora infestans in Dutch potato fields. Netherlands Journal of Plant Pathology, 87, 65–68. doi:10.1007/BF01976658.CrossRefGoogle Scholar
  5. Forbes, G. A., Escobar, X. C., Ayala, C. C., Revelo, J., Ordoñez, M. E., Fry, B. A., et al. (1997). Population genetic structure of Phytophthora infestans in Ecuador. Phytopathology, 87, 375–380. doi:10.1094/PHYTO.1997.87.4.375.PubMedCrossRefGoogle Scholar
  6. Forbes, G. A., Goodwin, S. B., Drenth, A., Oyarzún, P., Ordoñez, M. E., & Fry, W. E. (1998). A global marker database for Phytophthora infestans. Plant Disease, 82, 811–818. doi:10.1094/PDIS.1998.82.7.811.CrossRefGoogle Scholar
  7. Fry, W. (2008). Phytophthora infestans: the plant (and R gene) destroyer. Molecular Plant Pathology, 9, 385–402. doi:10.1111/j.1364-3703.2007.00465.x.PubMedCrossRefGoogle Scholar
  8. Fry, W. E., Goodwin, S. B., Matuszak, J. M., Spielman, L. J., Milgroom, M. G., & Drenth, A. (1992). Population genetics and intercontinental migrations of Phytophthora infestans. Annual review of Phytopathology, 30, 107–129. doi:10.1146/ Scholar
  9. Fry, W. E., Grünwald, N. J., Cooke, D. E. L., McLeod, A., Forbes, G. A., & Cao, K. (2009) Population genetics and population diversity of Phytophthora infestans. In: K. Lamour K, Kamoun S, (ed.). Oomycete genetics and genomics: Biology, interactions with plants and animals, and toolbox. (in press). New York: Wiley.Google Scholar
  10. Garry, G., Forbes, G. A., Salas, A., Cruz, M. S., Perez, W., & Nelson, R. J. (2005a). Genetic diversity and host differentiation among isolates of Phytophthora infestans from cultivated potato and wild solanaceous hosts in Peru. Plant Pathology, 54, 740–748. doi:10.1111/j.1365-3059.2005.01250.x.CrossRefGoogle Scholar
  11. Garry, G., Salas, A., Forbes, G. A., Perez, W., Cruz, M. S., & Nelson, R. J. (2005b). Host specialization not detected in isolates of Phytophthora infestans attacking wild and cultivated potatoes in Peru. European Journal of Plant Pathology, 113, 71–81. doi:10.1007/s10658-005-1225-9.CrossRefGoogle Scholar
  12. Georgopoulos, S. G. (1982). Recommended methods for the detection and measurement of resistance of agricultural pests to pesticides. FAO Plant Protection Bulletin, 30, 36–71.Google Scholar
  13. Gisi, U., Hermann, D., Ohl, L., & Steden, C. (1997). Sensitivity profiles of Mycosphaerella graminicola and Phytophthora infestans populations to different classes of fungicides. Pesticide Science, 51, 290–298. doi:10.1002/(SICI)1096-9063(199711) 51:3<290::AID-PS637>3.0.CO;2-H.CrossRefGoogle Scholar
  14. Goodwin, S. B., Drenth, A., & Fry, W. E. (1992). Cloning and genetic analyses of two highly polymorphic, moderately repetitive nuclear DNAs from Phytophthora infestans. Current Genetics, 22, 107–115. doi:10.1007/BF00351469.PubMedCrossRefGoogle Scholar
  15. Grünwald, N. J., Sturbaum, A. K., Montes, G. R., Serrano, E. G., Lozoya Saldana, H., & Fry, W. E. (2006). Selection for fungicide resistance within a growing season in field populations of Phytopthora infestans at the center of origin. Phytopathology, 96, 1397–1403. doi:10.1094/PHYTO-96-1397.PubMedCrossRefGoogle Scholar
  16. Gullino, M. L., Mescalchin, E., & Mezzalama, M. (1997). Sensitivity to cymoxanil in populations of Plasmopara viticola in northern Italy. Plant Pathology, 46, 729–736. doi:10.1046/j.1365-3059.1997.d01-68.x.CrossRefGoogle Scholar
  17. Hamlen, R. A., & Power, R. J. (1998). Distribution of sensitivity responses to cymoxanil within global populations of Phytophthora infestans. Pesticide Science, 53, 101–103. doi:10.1002/(SICI)1096-9063(199805)53:1<101::AID-PS737>3.0.CO;2-R.CrossRefGoogle Scholar
  18. Hannukkala, A. O., Kaukoranta, T., Lehtinen, A., & Rahkonen, A. (2007). Late-blight epidemics on potato in Finland, 1933-2002; increased and earlier occurrence of epidemics associated with climate change and lack of rotation. Plant Pathology, 56, 167–176. doi:10.1111/j.1365-3059.2006.01451.x.CrossRefGoogle Scholar
  19. Hsiang, T., Yang, L., & Barton, W. (1997). Baseline sensitivity and cross-resistance to demethylation-inhibiting fungicides in Ontario isolates of Sclerotinia homeocarpa. European Journal of Plant Pathology, 103, 409–416. doi:10.1023/A:1008671321231.CrossRefGoogle Scholar
  20. Judelson, H. S. (1996). Chromosomal heteromorphism linked to the mating type locus of the oomycete Phytophthora infestans. Molecular & General Genetics, 252, 155–161. doi:10.1007/BF02173215.CrossRefGoogle Scholar
  21. Kato, M., Mizubuti, E. S., Goodwin, S. B., & Fry, W. E. (1997). Sensitivity to protectant fungicides and pathogenic fitness of clonal lineages of Phytophthora infestans in the United States. Phytopathology, 87, 973–978. doi:10.1094/PHYTO.1997.87.9.973.PubMedCrossRefGoogle Scholar
  22. Klinkenberg HJ, Stierl R and Dehne HW (1998) Investigations on fungicide resistance in oomycetes. Mededelingen van de Faculteit Landbouwwetenschappen Universiteit Gent, 63(3b), 1009–1015. ISSN/ISBN: 0368-9697.Google Scholar
  23. Kromann, P., Leon, D., Andrade-Piedra, J., & Forbes, G. A. (2008). Comparison of alternation with a contact fungicide and sequential use of the translaminar fungicide cymoxanil in the control of potato late blight in the highland tropics of Ecuador. Crop Protection (Guildford, Surrey), 27, 1098–1104. doi:10.1016/j.cropro.2008.01.006.CrossRefGoogle Scholar
  24. Marucchini, C., & Zadra, C. (2002). Stereoselective degradation of metalaxyl and metalaxyl-M in soil and sunflower plants. Chirality, 14, 32–38. doi:10.1002/chir.10032.PubMedCrossRefGoogle Scholar
  25. Mukalazi, J., Adipala, E., Sengooba, T., Hakiza, J. J., Olanya, M., & Kidanemariam, H. M. (2001). Metalaxyl resistance, mating type and pathogenicity of Phytophthora infestans in Uganda. Crop Protection (Guildford, Surrey), 20, 379–388. doi:10.1016/S0261-2194(00)00145-9.CrossRefGoogle Scholar
  26. Parra, G. R., & Ristaino, J. B. (2001). Resistance to mefenoxam and metalaxyl among field isolates of Phytophthora capsici causing Phytophthora blight of bell pepper. Plant Disease, 85, 1069–1075. doi:10.1094/PDIS.2001.85.10.1069.CrossRefGoogle Scholar
  27. Perez, W. G., Gamboa, J. S., Falcon, Y. V., Coca, M., Raymundo, R. M., & Nelson, R. J. (2001). Genetic structure of Peruvian populations of Phytophthora infestans. Phytopathology, 91, 956–965. doi:10.1094/PHYTO.2001.91.10.956.PubMedCrossRefGoogle Scholar
  28. Power, R. J., Hamlen, R. A., & Morehart, A. L. (1995). Variation in sensitivity of Phytophthora infestans field isolates to cymoxanil, chlorothalonil and metalaxyl. In L. J. Dowley, E. Bannon, L. R. Cooke, T. Keane & E. O'Sullivan (Eds.), Phytophthora infestans 150, pp. 154–159. Dublin, Ireland: Boole Press Ltd.Google Scholar
  29. Reis, A., Ribeiro, F. H. S., Maffia, L. A., & Mizubuti, E. S. G. (2005). Sensitivity of Brazilian isolates of Phytophthora infestans to commonly used fungicides in tomato and potato crops. Plant Disease, 89, 1279–1284. doi:10.1094/PD-89-1279.CrossRefGoogle Scholar
  30. Samoucha, Y., & Cohen, Y. (1988). Sensitivity of Phytophthora infestans to cymoxanil. Phytoparasitica, 16, 39–45. doi:10.1007/BF02979575.CrossRefGoogle Scholar
  31. Spielman, L. J., Drenth, A., Davidse, L. C., Sujkowski, L. J., Gu, W., Tooley, P. W., et al. (1991). A second world-wide migration and population displacement of Phytophthora infestans?. Plant Pathology, 40, 422–430. doi:10.1111/j.1365-3059.1991.tb02400.x.CrossRefGoogle Scholar
  32. Sujkowski, L. S., Fry, B. A., Power, R. J., Goodwin, S. B., Peever, T. L., Hamlen, R. A., et al. (1995). Sensitivities of Mexican isolates of Phytophthora infestans to chlorothalonil, cymoxanil, and metalaxyl. Plant Disease, 79, 1117–1120.Google Scholar
  33. Taylor, R. J., Pasche, J. S., & Gudmestad, N. C. (2006). Biological significance of mefenoxam resistance in Phytophthora erythroseptica and its implications for the management of pink rot of potato. Plant Disease, 90, 927–934. doi:10.1094/PD-90-0927.CrossRefGoogle Scholar
  34. Therrien, C. D., Tooley, P. W., Spielman, L. J., Fry, W. E., Ritch, D. L., & Shelly, S. E. (1993). Nuclear DNA content, allozyme phenotypes and metalaxyl sensitivity of Phytophthora infestans from Japan. Mycological Research, 97, 945–950. doi:10.1016/S0953-7562(09) 80860-5.CrossRefGoogle Scholar
  35. Ziogas, B. N., & Davidse, L. C. (1987). Studies on the mechanism of action of cymoxanil in Phytophthora infestans. Pesticide Biochemistry and Physiology, 29, 89–96. doi:10.1016/0048-3575(87)90066-6.CrossRefGoogle Scholar

Copyright information

© KNPV 2009

Authors and Affiliations

  • Wilmer Pérez
    • 1
  • Johanna Lara
    • 2
  • Gregory A. Forbes
    • 1
  1. 1.International Potato Centre (CIP)Lima 12Peru
  2. 2.Universidad Nacional Agraria La MolinaLimaPeru

Personalised recommendations