IDENTIFICATION OF SOME CULTIVARS OF BRASSICA NAPUS WITH RESISTANCE AT VERTICILLIUM LONGISPORUM

Verticillium longisporum is a soil born vascular fungal pathogen on Brassicas oil crops (Heale et al. 1999). Due of the high demand for rapeseed oil, the area under oilseed rape cultivation continues to rise dramatically (Eynck et al 2008). The current European cultivar poses a low level of resistance for this disease, so a severe infection can produce major yield losses. The fungus is able to survive in the soil for several years through the production of microsclerotia and because until now there are no approved fungicide available for V. longisporum resistant cultivars of oilseed rape are required. Resistance to Verticillium spp. is known from several other crops like tomato (Diwan et al. 1999), potato (Jansky et al. 2004), cotton (Bolek et al. 2005), and strawberry (Lynch et al. 1997). At the present, there are no resistant oilseed rape cultivars available for this disease, so the identification of some new resistance sources is very important for further studies in oilseed rape breeding process. The aim of this study was to identify some oilseed rape cultivars with resistance to Verticillium longisporum. For this purpose we tested a number of 39 cultivars of oilseed rape cultivars for their resistance to Verticillium longisporum by artificial infection. The experiments were conducted in the climatic chamber under controlled condition. Tendays seedlings were artificial infected with the pathogen by root deep inoculation. The winter oilseed rape varieties Express (less susceptible) and Falcon (highly susceptible) were used as reference controls in our experiment. Disease scores were taken weekly for each plant for a four week period using an assessment key with nine classes. Based on this data for each accession was calculated area under disease progress curve (AUDPC). Analyzing the obtained data, we identified a number of 7 cultivars with a high level of resistance which could be some new resistance sources that could be used in the future for in the breeding programs for obtaining some resistant oilseed rape cultivars to Verticillium longisporum.