An overview of bacterial blight disease of rice and strategies for its management

This is a status paper on a destructive rice disease bacterial blight (BB), caused by Xanthomonas oryzae pv, oryzae (Xoo), We review the occurrence an d spread of this disease, the taxonomy and classification of the pathogen a nd strategies for disease management. Studies on pathogen variation have re vealed that breeding with single major genes for resistance, may be ineffec tive due to resistance breakdown. Thus, pyramiding of resistance genes appe ars to be a good option for disease management. Evidence from our laborator y suggests that BE of rice can be managed through carefully selected biolog ical control agents which can be used by themselves or can work in combinat ion with single major genes for BE resistance (e.g. Xa4), We also present t he view that elite indica rice cultivars can be constructed through traditi onal breeding and transgenic approaches to incorporate pyramids of blast an d BE resistance genes to effectively manage these two devastating rice prod uction constraints and to sustain rice yields in India.