In order to clarify the role of PlPMI3 resistance gene in sunflower differential lines D4 for differentiation the pathogenicity in Plasmopara halstedii (sunflower downy mildew), analyses were carried out in two groups including four pathotypes which overcome and do not overcome PlPMI3 (Pl gene has still not been mapped) resistance gene. Based on the reaction for the P. halstedii isolates to sunflower hybrids varying only in Pl resistance genes, there were no virulence differences for the two groups. Index of aggressiveness was calculated for pathogen isolates and revealed the presence of significant differences between isolates of races 304 and 314; however, there were no aggressiveness differences for 7xx races. Regarding the life-history trait and the genetic architecture of the pathogen: there were morphological and genetic variations for the four P. halstedii isolates without a correlation with pathogenic diversity. The importance of the PlPMI3 resistance gene to differentiate the pathogenicity in sunflower downy mildew was discussed.
Ahmed, S., Delmotte, F. and Tourvieille de Labrouhe, D. (2012): Emerging virulence arising from hybridisation facilitated by multiple introductions of the sunflower downy mildew pathogen Plasmopara halstedii. Fungal Genet. Biol. 49, 847–855.
Delmotte, F., Giresse, X., Richard-Cervera, S., M’baya, J., Vear, F., Tourvieille, J., Walser, P. and Tourvieille de Labrouhe D. (2008): Single nucleotide polymorphisms reveal multiple introductions into France of Plasmopara halstedii, the plant pathogen causing sunflower downy mildew. Infect. Genet. Evol. 8, 534–540.
Delmotte, F., Mestre, P., Schneider, C., Kassemeyer, H. H., Kozma, P., Richart-Cervera, S., Rouxel, M. and Deliere, L. (2014): Rapid and multiregional adaptation to host partial resistance in a plant pathogenic oomycete: Evidence from European populations of Plasmopara viticola, the causal agent of grapevine downy mildew. Infect. Genet. Evol. 27, 500–508.
Jin, L. and Chakraborty, R. (1993): Estimation of genetic distance and coefficient of gene diversity from single- probe multilocus DNA fingerprinting data. Mol. Biol. Evol. 11, 120–127.
Lannou, C. (2012): Variation and selection of quantitative traits in plant pathogens. Annu. Rev. Phytopathol. 50, 319–338.
Librado, P. and Rozas, J. (2009): DnaSP v5: a software for comprehensive analysis of DNA polymorphism data. Bioinformatics 25, 1451–1452.
Miller, J. F. and Gulya, T. J. (1991): Inheritance of resistance to race 4 of downy mildew derived from interspecific crosses in sunflower. Crop Sci. 31, 40–43.
Pariaud, B., Goyeau, H., Halkett, F., Robert, C. and Lannou, C. (2012): Variation in aggressiveness is detected among Puccinia triticina isolates of the same pathotype and clonal lineage in the adult plant stage. Eur. J. Plant Pathol. 134, 733–743.
Radwan, O., Bouzidi, M. F., Vear, F., Phillipon, J., Tourvieille de Labrouhe, D., Nicolas, P. and Mouzeyar, S. (2003): Identification of non TIR-NBS-LRR markers linked to the PL5/PL8 locus for resistance to downy mildew in sunflower. Theor. Appl. Genet. 106, 1438–1446.
Radwan, O., Bouzidi, M. F. and Mouzeyar, S. (2011): Molecular characterization of two types of resistance in sunflower to Plasmopara halstedii, the causal agent of downy mildew. Phytopathology 101, 970–979.
Sakr, N. (2011a): Aggressiveness in Plasmopara halstedii (sunflower downy mildew). Plant Pathol. J. 27, 110–115.
Sakr, N. (2011b): Evolution of pathogenicity in Plasmopara halstedii (sunflower downy mildew). Arch. Phytopathol. Plant Protect 44, 1432–1436.
Sakr, N. (2011c): Relationship between aggressiveness and zoosporangia viability in Plasmopara halstedii (sunflower downy mildew). Arch. Phytopathol. Plant Protect 44, 1585–1594.
Sakr, N. (2012): Virulence cost in Plasmopara halstedii (sunflower downy mildew). Arch. Phytopathol. Plant Protect 45, 646–651.
Sakr, N. (2014a): Evolution of new Plasmopara halstedii races under the selection pressure with resistant sunflower plants: A review. Hellenic Plant Protect J. l7, 1–13.
Sakr, N. (2014b): Determining the fitness cost associated with virulence in Plasmopara halstedii (sunflower downy mildew). Acta Phytopathol. et Entomol. Hung. 49, 201–210.
Sakr, N. (2014c): Pathogenicity in Plasmopara halstedii (sunflower downy mildew) races 710, 714 and 704. Acta Phytopathol. et Entomol. Hung. 49, 11–24.
Sakr, N. (2015a): Emergence of new virulence in Plasmopara halstedii (sunflower downy mildew). Acta Phytopathol. et Entomol. Hung. 50, 17–28.
Sakr, N. (2015b): Intra- and inter-isolate variation in two predominant Plasmopara halstedii (sunflower downy mildew) races in Europe. Botanica Serbica 39, 1–8.
Sakr, N., Ducher, M., Tourvieille, J., Walser, P. and Tourvieille de Labrouhe, D. (2007): A new method to obtain monozoosporangial isolates of sunflower downy mildew (Plasmopara halstedii). Cryptogamie Mycologie 28, 123–131.
Snedecor, G. W. and Gochran, W. G. (1989): Statistical Methods. The Iowa State University Press, Ames, Iowa, pp. 1–528.
Stukenbrock, E. H. and McDonald, B. A. (2008): The origins of plant pathogens in agro-ecosystems. Ann. Rev. Phytopathol. 46, 75–100.
Tourvieille de Labrouhe, D., Pilorge, E., Nicolas, P. and Vear, F. (2000): Le mildiou du tournesol. CETIOMINRA Publications, pp. 1–176.
Tourvieille de Labrouhe, D., Serre, F., Roche, S., Walser, P. and Vear, F. (2008): Quantitative resistance to downy mildew (Plasmopara halstedii) in sunflower (Helianthus annuus). Euphytica 164, 433–444.
Tourvieille de Labrouhe, D., Bordat, A., Tourvieille, J., Mestries, E., Walser, P., Sakr, N., Ducher, M., Delmotte, F. and Vear, F. (2010): Impact of major gene resistance management for sunflower on fitness of Plasmopara halstedii (downy mildew) populations. Oleagineux, Corps Gras, Lipides 17, 56–64.
Van der Plank, J. E. (1968): Disease Resistance in Plants. Academic Press, New York, pp. 1–206.
Vear, F., Gentzbittel, L., Philippon, J., Mouzeyar, S., Mestries, E., Roeckel-Drevet, P., Tourvieille de Labrouhe, D. and Nicolas, P. (1997): The genetics of resistance to five races of downy mildew (Plasmopara halstedii) in sunflower (Helianthus annuus L.). Theor. Appl. Genet. 95, 584–589.
Vear, F., Tourvieille de Labrouhe, D. and Miller, J. F. (2003): Inheritance of the wide-range downy mildew resistance in the sunflower line RHA 419. Hella 26, 19–24.
Virányi, F. and Spring, O. (2011): Advances in sunflower downy mildew research. Eur. J. Plant Pathol. 129, 207–220.