Environment-friendly integrated control of a plant disease necessitates (i) a good knowledge of the pathogen, including its interactions with the host plant(s) and population structure; (ii) an understanding of the epidemiology and of the weather factors leading to damaging epidemics, in order to establish risk forecasting assays and Ciii) a diverse range of sources of resistance, an assessment of their efficiency under the most diverse situations allowing to predict their behaviour when submitted to different climates and populations of the pathogen.
The objectives of the proposed 4-year project is to address these points to propose integrated strategies to control the most damaging disease of oilseed rape and vegetable Brassicas in Europe: the stem canker (also termed Phoma and blackleg disease of crucifers), caused by the fungal pathogen Leptosphaeria maculans (anamorph: Phoma lingam). This work will assess the efficiency of resistance currently available in oilseed rape under various situations, identify novel sources of resistance, and propose disease resistance strategies fitting each specific European situation, i.e. France, Germany, the UK, Poland and Portugal. A large number of L. maculans isolates will be collected frm diverse locations and crops in Europe. The collection will be analysed according to biological, biochemical and molecular criteria and compared to world-wide reference isolates. Simultaneously, a four-year epidemiological survey will be performed in parallel in the UK, France and Poland, both n field and controlled conditions. me main races and/or species identified in the European survey will be used for epidemiological studies and - o screen for resistance in a collection of more than 700 accessions of B. oleracea, B. rape and B. napus, including rare germplasm. The genetic analysis of the interactions will be performed on both the host and the pathogen, in order to understand the genetic control of the resistance and to standardize race nomenclature. PCR-based assays will be developed to design specific diagnosis tools that will allow recognition of all species, and probably races, involved in the stem canker disease and that will be used for further epidemiological studies.
Finally, the efficiency of resistance sources will be assessed under field conditions. Novel and promising resistance sources will be included immediately in breeding programs. The production of commercial varieties from new resistance sources will be enhanced using molecular markers of resistance genes for marker-assisted breeding, in conjunction with obtainment of di-haploids and the use of rapid-cycling Brassicas.
Such a program can only be carried out through a collaborative work using a common collection of isolates, numerous and rare accessions of Brassica, diverse field conditions, and using expertise in agrometeorology and epidemiology, biochemistry and molecular biology, and fungal and plant genetics.
The proposed project groups together two teams involved in plant breeding, including a private Company which will be in charge of further commercialisation of the results of this work, two teams specialized in epidemiological studies, and three teams specializing in the microbiology of h.maculans : characterization, fungal genetics, interaction appraisal and molecular biology.
This project specifically relates to task 4.4.1 (plant health). The expected results are (i) risk forecasting methods using both the data regarding the structure of European populations and the epidemiology of the pathogen(s); (ii) improved methods for identification and detection of the pathogens) in seed lots or in planta; (iii) characterization of efficient resistance genes for an environment-friendly control of blackleg. Finally, this program aims at suggesting long-term strategies for management of resistance.
Funding SchemeCSC - Cost-sharing contracts
AL5 2JQ Harpenden