Alternaria Blight of Brassicas: Identification, Characterization, Epidemiology and Management

Contents: Introduction. 1. Background. 2. Strategies for Disease Management. 3. Past Studies. 4. The Pathogen. 5. Epidemiology. 6. Research Methodology. 7. Results and Discussion. 8. Summary and Conclusions. Appendix.

Rapeseed and mustard form an important part of the total oilseed production in India. Among the different biotic stresses which influence the performance of rapeseed and mustard, Alternaria blight disease caused by Alternaria brassicae (Berk.) Sacc. is considered as one of the major yield attributing factor in West Bengal causing considerable losses to the crop. In view of the potentiality of the disease and its annual recurrence in unpredictable climatic condition facing off now in lateritic belt of West Bengal, attempts were made for studying the Alternaria blight of mustard with a view to get information on the existing isolates of the pathogen, their potential level of natural incidence, disease – environmental relationship and to explore the possibilities of controlling the disease with the help of SAR chemicals, biological agents and by selecting some resistant cultivars suitable for this location. An attempt was also made for development of a probable potent marker in relation to Alternaria blight resistance. RAPD profile analysis was carried out using different RAPD primers and extent of polymorphism with each primer was studied. Using the RAPD derived finger print profiles using selected primers, amplicon size for susceptible, moderately susceptible, highly susceptible and moderately resistant genotypes was also determined which formed the baseline for development of Alternaria blight resistant marker. Cluster analysis using morphological (epidemiological) traits and RAPD fingerprint profiles were also found to exhibit parallelism forming an important aspect of the study undertaken. This book is the final outcome of that exploratory/scientific research.