Introgression of effective bacterial blight resistant genes into rice cultivars and hybrid rice parental lines

Using marker-assisted selection in a backcross-breeding program, four bacterial blight resistant genes namely Xa4, xa5, xa13 and Xa21 have been introgressed into the popular hybrid rice parental lines KMR3, PRR78, IR58025B, Pusa 6B and a popular variety Mahsuri. Only foreground selection was done using markers. Conventional breeding strategy was adopted for background selection. The pyramids showed very high level of disease resistance to 10 highly virulent isolates of Xoo. Grain quality parameters of the pyramids were on par with that of the original genotype. This work demonstrates the successful application of marker-assisted breeding for pyramiding four BB resistant genes into multiple backgrounds, simultaneously. These lines can be used directly or can be used as donors of bacterial blight (BB) resistance breeding.