Diversity in Puccinia graminis f. sp. avenae and its impact on oat cultivar response in South Africa

  • W. H. P. BoshoffEmail author
  • B. Visser
  • T. Terefe
  • Z. A. Pretorius


Puccinia graminis f. sp. avenae (Pga) samples were collected from cultivated oat (Avena sativa L.) in trial plots and commercial fields and from wild oat (Avena spp.) during the 2016 and 2017 seasons. Field samples were purified through selection of single pustule isolates and subsequent urediniospore increases using the susceptible cultivar Swan. For race phenotyping, a set of 12 international differential lines was used that resulted in the identification of races RSJ, RJS and RJJ. Race RSJ was the most prevalent (60% of isolates) followed by races RJS (34%) and RJJ (6%). These races varied in virulence for Pg6 and Pg12, with no avirulence recorded for Pg1, 2, 4, 8, 9, 13 and Pg15 and no virulence for Pg3, 10 and Pg16. Seedling infection types of 32 oat cultivars to the three described races showed compatible phenotypes for all cultivars towards at least one of the races. Moderate levels of adult plant resistance against races RJS and RSJ were recorded for seven cultivars during field tests in 2017 and 2018. Thirteen microsatellite markers used to assess genetic variability amongst twenty four field isolates revealed three sub-populations of which only one correlated with the race phenotype. The results contributed to our understanding of the diversity of the Pga population in South Africa, including useful resistance sources and cultivar responses.


Puccinia graminis f. sp. avenae Oat stem rust Pathogenic variation Cultivar response 



Producers and dealers of oat seed in SA (Agricultural Research Council – Small Grain, Agricol, Barenbrug, Capstone, K2, Pannar Seed and Sensako) are acknowledged for making seed of their cultivars available. Pannar Seed is thanked for the maintenance of field trials. Dr. Tom Fetch (Agriculture and Agri-Food Canada) and Prof Robert Park (Plant Breeding Institute, The University of Sydney) are thanked for providing seed of differential lines.

Funding information

The National Research Foundation (SARChI chair UID 8464) is thanked for funding.

Compliance with ethical standards

We hereby declare that our submission is in compliance with the ethical responsibilities and standards of the EJPP as well as those of the University of the Free State.

Conflict of interest

The authors declare that they have no conflict of interest.


  1. Berlin, A., Samils, B., Djurle, A., Wirsén, H., Szabo, L., & Yuen, J. (2013). Disease development and genotypic diversity of Puccinia graminis f. sp. avenae in Swedish oat fields. Plant Pathology, 62, 32–40.CrossRefGoogle Scholar
  2. Boshoff, W. H. P., Pretorius, Z. A., Terefe, T., Bender, C. M., Herselman, L., Maree, G. J., & Visser, B. (2018). Phenotypic and genotypic description of Puccinia graminis f. sp. tritici race 2SA55 in South Africa. European Journal of Plant Pathology, 152, 783–789.CrossRefGoogle Scholar
  3. Brown, K. M., & Hovmøller, M. S. (2002). Aerial dispersal of pathogens on the global and continental scales and its impact on plant disease. Science, 297, 537–541.CrossRefGoogle Scholar
  4. DAFF. (2017). A profile of the south African oats market value chain. Forestry and Fisheries, Pretoria, South Africa: Department of Agriculture Accessed 9 April 2017
  5. Evanno, G., Regnaut, S., & Goudet, J. (2005). Detecting the number of clusters of individuals using software STRUCTURE: A simulation study. Molecular Ecology, 14, 2611–2620.CrossRefGoogle Scholar
  6. Excoffier, L., Laval, G., & Schneider, S. (2005). Arlequin ver 3.0: An integrated software package of population genetics data analysis. Evolutionary Bioinformatics Online, 1, 47–50.Google Scholar
  7. Fetch, T. G., Jr. (2006). Effect of temperature on the expression of seedling resistance to Puccinia graminis f. sp. avenae in oat. Canadian Journal of Plant Pathology, 28, 558–565.CrossRefGoogle Scholar
  8. Fetch, T. G., Jr., & Jin, Y. (2007). Letter code system of nomenclature for Puccinia graminis f. sp. avenae. Plant Disease, 91, 763–766.CrossRefGoogle Scholar
  9. Fetch, T. G., Jr., Fetch, M., Zegeye, T., & Xue, A. (2015). Races of Puccinia graminis on wheat, oat, and barley in Canada in 2009 and 2010. Canadian Journal of Plant Pathology, 37, 476–484.CrossRefGoogle Scholar
  10. Gnocato, F. S., Dracatos, P. M., Karaoglu, H., Zhang, P., Berlin, A., & Park, R. F. (2018). Development, characterisation and application of genomic SSR markers for the oat stem rust pathogen Puccinia graminis f. sp. tritici. Plant Pathology, 67, 457–466.CrossRefGoogle Scholar
  11. Goyeau, H., Halkett, F., Zapater, M. F., Carlier, J., & Lannou, C. (2007). Clonality and host selection in the wheat pathogenic fungus Puccinia triticina. Fungal Genetic Biology, 44, 474–483.CrossRefGoogle Scholar
  12. Haque, S., Park, R. F., Keiper, F. J., Bariana, H. S., & Wellings, C. R. (2008). Pathogenicity and molecular variation support the presence of genetic distinct clonal lineages in Australian populations of Puccinia graminis f. sp. avenae. Mycological Research, 112, 663–673.CrossRefGoogle Scholar
  13. Keiper, F. J., Haque, M. S., Hayden, M. J., & Park, R. F. (2006). Genetic diversity in Australian populations of Puccinia graminis f. sp. avenae. Phytopathology, 96, 96–104.CrossRefGoogle Scholar
  14. Kolmer, J. A., Mirza, J. I., Imtiaz, M., & Shah, S. J. A. (2017). Genetic differentiation of the wheat leaf rust fungus Puccinia triticina in Pakistan and genetic relationship to other worldwide populations. Phytopathology, 107, 786–790.CrossRefGoogle Scholar
  15. Li, T., Cao, Y., Wu, X., Chen, S., Wang, H., Li, K., & Shen, L. (2015). First report on race and virulence characterization of Puccinia graminis f. sp. avenae and resistance of oat cultivars in China. European Journal of Plant Pathology, 142, 85–91.CrossRefGoogle Scholar
  16. McIntosh, R. A., Wellings, C. R., & Park, R. F. (1995). Wheat rusts: An atlas of resistance genes. Dordrecht: Kluwer Academic Publishers.CrossRefGoogle Scholar
  17. Meldrum, S., & Oates, J. D. (1997). Oat stem rust. Annual report, Cereal Rust Survey 1996–97 (pp. 11–13). Cobbity, University of Sydney, Camden: Plant Breeding Institute.Google Scholar
  18. Neethling, J. H. (1932). Wheat varieties in South Africa - their history and development until 1912. Science bulletin no. 108, Department of Agriculture, Union of South Africa, p 1-40.Google Scholar
  19. Perrier, X., Flori, A., & Bonnot, F. (2003). Data analysis methods. In P. Hamon, M. Seguin, X. Perrier, & J. C. Glazmann (Eds.), Genetic diversity of cultural tropical plants (pp. 43–76). Enfield, UK: Science Publishers.Google Scholar
  20. Peterson, R. F., Campbell, A. B., & Hannah, A. E. (1948). A diagrammatic scale for estimating rust intensity of leaves and stems of cereals. Canadian Journal of Research Section C, 26, 496–500.CrossRefGoogle Scholar
  21. Pritchard, J. K., Stephens, M., & Donnelly, P. (2000). Inference of population structure using multilocus genotype data. Genetics, 155, 945–959.PubMedPubMedCentralGoogle Scholar
  22. Roelfs, A. P., Singh, R. P., & Saari, E. E. (1992). Rust diseases of wheat: Concepts and methods of disease management. Mexico: CIMMYT.Google Scholar
  23. Saghai-Maroof, M. A., Soliman, K. M., Jorgensen, R. A., & Allard, R. W. (1984). Ribosomal DNA spacer-length polymorphisms in barley: Mendelian inheritance, chromosomal location and population dynamics. Proceedings National Academy Science USA, 81, 8014–8018.Google Scholar
  24. Sambrook, J., Fritsch, E. F., & Maniatis, T. (1989). Molecular cloning, a laboratory manual (2nd ed.). New York: Cold Spring Harbor Laboratory Press.Google Scholar
  25. Sihlobo, W. (2017). Global view on oat production. Agricultural business chamber e-newsletter 17–03, Pretoria, South Africa. (accessed 9 April 2019).
  26. Van Niekerk, B. D., Pretorius, Z. A., & Boshoff, W. H. P. (2001a). Pathogenic variability of Puccinia coronata f. sp. avenae and P. graminis f. sp. avenae on oat in South Africa. Plant Disease, 85, 1085–1090.CrossRefGoogle Scholar
  27. Van Niekerk, B. D., Pretorius, Z. A., & Boshoff, W. H. P. (2001b). Potential yield losses caused by barley leaf rust and oat leaf rust and stem rust to south African barley and oat cultivars. South African Journal of Plant and Soil, 18, 108–113.CrossRefGoogle Scholar
  28. Visser, B., Herselman, L., & Pretorius, Z. A. (2009). Genetic comparison of Ug99 with selected south African races of P. graminis f. sp. tritici. Molecular Plant Pathology, 10, 213–222.CrossRefGoogle Scholar
  29. Visser, B., Herselman, L., Bender, C. M., & Pretorius, Z. A. (2012). Microsatellite analysis of selected Puccinia triticina races in South Africa. Australasian Plant Pathology, 41, 165–171.CrossRefGoogle Scholar
  30. Visser, B., Meyer, M., Park, R. F., Gilligan, C. A., Burgin, L. E., Hort, M. C., Hodson, D. P., & Pretorius, Z. A. (2019). Microsatellite analysis and urediniospore dispersal simulations support the movement of Puccinia graminis f. sp. tritici from southern Africa to Australia. Phytopathology, 109, 133–144.CrossRefGoogle Scholar
  31. Wright, S. (1951). The genetic structure of populations. Annals of Eugenetics, 15, 323–354.CrossRefGoogle Scholar
  32. Zadoks, J. C., Chang, T. T., & Konzak, C. F. (1974). A decimal code for the growth stages of cereals. Weed Research, 14, 415–421.CrossRefGoogle Scholar

Copyright information

© Koninklijke Nederlandse Planteziektenkundige Vereniging 2019

Authors and Affiliations

  1. 1.Department of Plant SciencesUniversity of the Free StateBloemfonteinSouth Africa
  2. 2.Agricultural Research Council - Small GrainBethlehemSouth Africa

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