Introduction of a new specific resistance against Leptosphaeria maculans in oilseed rape commercial varieties in France: Monitoring of introduction and control of virulence behaviour to try to avoid resistance break down in a pilot production area in the central part of France
Recently new genotypes of oilseed rape were introduced commercially. Their excellent resistance to blackleg (Leptosphaeria maculans) is mainly due to a new major resistance gene Rlm7. Such varieties are potentially exposed to a resistance break down risk. That is the reason why we promote specific extension activities and a monitoring in a production area where the risk seems to be particularly high. This area of around 100 Km2 is located in the central region of France between the 2 towns of Issoudun and St Florent sur Cher. In this area 20 to 30 farmers fields are observed each year. Rlm7 varieties, slightly introduced the previous year, represent 5 ％ of the total oilseed rape surface in 2005-2006 cropping season. Observations over the seasons include agronomic diagnosis, ascospores releases each autumn, and leaf spots sampling. From sampled leaves, fungus isolates were purified and characterized for virulence profiles. Particular attention was paid to virulence on the Rlm7 refennce host. This paper presents results from the two first cropping years. Only a single isolate each year was ídentified as virulent on Rlm7 reference host, suggesting that the specific resistance would probably stay efficient in the next closed future, even if the virulent inoculum is already present. Nevertheless, such experimental design will continue over the next cropping years, with the aim of been able to detect beginning of fungus population qualitative changes as early as possible.
Pinochet X. Penaud A. Sauzet G. Lodé M. Carpezat J. Pic E. Mestries E.
CETIOM Centre de Grignon, BP 4, 788850 Thiverval Grignon, France CETIOM 3 rue F.Pyat, 18400 Saint-Florent sur Cher, France
国际会议
第十二届国际油菜大会( The 12th International Rapeseed Congress)
武汉
英文
1301-1304
2007-03-26（万方平台首次上网日期，不代表论文的发表时间）