ABSTRACT
Breeders have successfully developed several rice cultivars lines resistant to diseases by integrating R-genes. However, durable, long-lasting resistance in many cases has been difficult to achieve as pathogens quickly evolve and develop counter resistance genes that circumvent the host cultivars resistance. Thus, there is need to speed up the breeding technologies with the help of new molecular tools. Nowadays, molecular breeding is used as genetic manipulation carried out at DNA levels to improve characters of interest in plants, including molecular marker-assisted selection and genomic selection. The rapid improvement in the field of molecular biology in the last few decades is very applicable to plant breeder for rice improvement. In India and the Philippines, bacterial blight resistance alleles of genes Xa4, xa5, xa13, Xa21, etc. have been successfully introgressed into several rice and hybrid rice varieties.
