Identification of bacterial blight resistance genes introgressed individuals in a segregating population of rice

Rice (Oryza sativa L.) is the most consumed food crop around the globe. Bacterial blight caused by Xanthomonas oryzae pv oryzae (Xoo) is the most destructive bacterial disease in rice. The cross CB 87 R × (CB 87 R × IRBB 60) was screened for three bacterial blight resistance genes Xa21, xa13 and xa5 with the help of molecular markers. This study revealed 15 individuals found to have resistance genes with different combinations. Furthermore, three individuals had all three genes in heterozygous conditions which was further surveyed for restoration of the fertility gene. The identified heterozygous plants with Rf gene were considered as an important criterion in the high yielding background individuals tagged and selfed and backcrossed with the recurrent parent to attain homozygosity. Once, these individuals stabilized, they could be used as genetic stocks for disease resistance breeding program in rice.