Analyzing the influence of qualitative resistance selection pressure on variation of aggressiveness in Plasmopara halstedii
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Syrian Atomic Energy Commission, Damascus, P.O. Box 6091, Syria
INRA-UBP, UMR 1095, 234 Avenue du Brézet, 63100 Clermont-Ferrand, France
UBP-UHR 1095, 24 Avenue des Landais, 63/77, Aubiére, France
INRA-UHR 1065, La Grande Ferrade, BP81, 33883 Villenave d’Ornon Ceder, France
Corresponding author
Nachaat Sakr
Syrian Atomic Energy Commission, Damascus, P.O. Box 6091, Syria
Journal of Plant Protection Research 2011;51(2):140-144
Variation of aggressiveness in populations of race 710 of Plasmopara halstedii [(Farl.) Berl. et Toni] (sunflower downy mildew) was measured under different strategies of qualitative resistance selection pressure: mixture, alternation and monoculture of major resistance genes in comparison with a population under no selection pressure. Two sunflower lines showing different levels of quantitative resistance were used to measure four aggressiveness criteria: percentage infection, latent period, sporulation density and reduction of hypocotyl length. P. halstedii strains multiplied under varietal mixtures presented the greatest sporulation densities and shortest hypocotyl lengths, those multiplied under alternation presented a reduced latent period and shorter hypocotyl lengths compared with those not influenced by selection pressure. There were no significant differences between populations multiplied under monoculture of resistance genes and those under no selection pressure. These changes appear as being linked to the number of infected plants present. The results suggested that the method of Pl gene management affects aggressiveness because it determines the number of susceptible plants harbored by the parasite.
The authors have declared that no conflict of interests exist.
Cowger C., Mundt C.C. 2002. Aggressiveness of Mycosphaerella graminicola isolates from susceptible and partially resistant wheat cultivars. Phytopathology 92 (6): 624–630.
Flier W.G., Kroon L.P.N.M., Hermansen A., Van Raaij H.M.G., Speiser B., Tamm L., Fuchs J.G., Lambion J., Razzaghian J., Andrivon D., Wilcockson S., Leifert C. 2007. Genetic structure and pathogenicity of populations of Phytophthora infestansfrom organic potato crops in France, Norway, Switzerland and the United Kingdome. Plant Pathol. 56 (4): 562–572.
Gandon S., Michalakis Y. 2000. Evolution of parasite virulence against qualitative or quantitative host resistance. Proc. Royal Soc. London 267 (1447): 985–990.
Gulya T.J. 2007. Distribution of Plasmopara halstedii races from sunflower around the world.p. 135–142. In: “Advances in Downy Mildew Research”. Vol. 3 Proc. 2nd International Downy Mildew Symposium. Palcky University in Olomouc and JOLA, v.o.s., Kostelec na Hane, Czech Republic, 2–6 July.
McDonald B.A., Linde C. 2002. Pathogen population genetics and the durability of disease resistance. Euphytica 124 (2): 163–180.
Kolmer J.A., Leonard K.J. 1986. Genetic selection and adaptation of Cochliobolus heterostrophus to corn hosts with partial resistance. Phytopathology 76 (8): 774–777.
Parisi L., Fouillet V., Schouten H.J., Groenwoil R., Laurens F., Didelot F., Evans K., Fischer C., Gennari F., Kemp H., Lateur M., Patocchi A., Thissen J., Tsipouridis C. 2004. Variability of the pathogenicity of Ventlia inaelalie in Europe. Acta Hortic. 663: 107–113.
Sakr N. 2009a. Components of quantitative resistance to downy mildew (Plasmopara halstedii) in sunflower (Helianthus annuus). J. Plant Protection Res. 49 (3): 297–301.
Sakr N., 2009b. Variation in aggressiveness of Plasmopara halstedii(sunflower downy mildew). J. Plant Dis. Protect. 116 (6):247–251.
Snedecor G.W., Gochran W.G. 1989. Statistical Methods. The Iowa State University Press, Iowa, USA,528 pp.
Sullivan M.J., Melton T.A., Shew H.D. 2005. Managing the race structure of Phytophthora parasitica var. nicotianae with cultivar rotation. Plant Dis. 89 (12): 1285–1294.
Tourvieille de Labrouhe D., Bordat A., Tourvieille J., Mestries E., Walser P., Sakr N., Ducher M., Delmotte F., Vear F. 2010. Impact of major gene resistance management for sunflower on fitness of Plasmopara halstedii(downy mildew) populations. Oleagineux, Corps Gras, Lipides 17 (2): 56–64.
Tourvieille de Labrouhe D., Pilorge E., Nicolas P., Vear F. 2000. Le Mildiou du Tournesol. CETIOM, INRA Editions, Paris, France, 176 pp.
Tourvieille de Labrouhe D., Serre F., Walser P., Roche S., Vear F. 2008. Quantitative resistance to downy mildew (Plasmopara halstedii) in sunflower (Helianthus annuus). Euphytica 164 (2): 433–444.
van der Plank J.E. 1968. Disease Resistance in Plants. Academic Press New York and London, 206 pp.
Vear F., Serre F., Roche S., Walser P., Tourvieille de Labrouhe D. 2007. Recent research on downy mildew resistance usetful for breeding industrial – use sunflower. Helia 30 (46): 45–54.
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