Marker-Assisted Development of Rice Line G163 Combining Pi2-Mediated Blast Resistance, Xa7-Mediated Bacterial Blight Resistance, and Favorable Grain Quality

Rice blast and bacterial blight are two major diseases that threaten rice production worldwide. Developing rice cultivars with both disease resistance and desirable grain quality is an important objective in modern rice breeding. In this study, R1179 carrying Pi2, Wxb and Alkb was crossed with IRBB7 carrying Xa7, Wxb and Alkb. Marker-assisted selection (MAS) was applied to an F2 population of 1123 plants, and a line, G163, combining Pi2, Xa7, Wxb and Alkb, was developed. Disease resistance evaluation showed that G163 retained the blast resistance conferred by Pi2 and the bacterial blight resistance conferred by Xa7, exhibiting resistance to the tested isolates of both pathogens. Grain quality assessment indicated that G163 possessed favorable milling, appearance and eating quality traits. Rapid Visco Analyzer (RVA) profiling further indicated desirable starch pasting properties. In conclusion, the rice line G163 carrying Pi2, Xa7, Wxb and Alkb was successfully developed through MAS. The results provide a useful germplasm resource for breeding rice cultivars with combined disease resistance and desirable grain quality.