Dr. Subhash NBhupendra S. Panwar2017-05-262017-05-262010http://krishikosh.egranth.ac.in/handle/1/5810012496Bacterial leaf blight caused by the bacterial pathogen Xanthomonas oryzae pv oryzae (Xoo) limits rice yield in all major rice growing regions of the world, especially in irrigated lowland and rainfed conditions where predisposition factors favor disease development to epidemic proportions. Since bacterial pathogens are difficult to manage, development of host plant resistance is the most effective means of disease management. As many as 31 major genes conferring resistance to various races of the pathogen have been identified and utilized in rice breeding programs. However, large-scale and long-term cultivation of varieties carrying a single gene for resistance resulted in a significant shift in pathogen race frequency with consequent breakdown of resistance in these cultivars. To combat the problem of resistance breakdown, pyramiding of resistance genes into different cultivars is being carried out. Availability of tightly linked marker for individual genes is the prerequisite for pyramiding of resistance genesenAgricultural BiotechnologyAnalysisThesis