Introgression of blast resistance genes into the elite rice variety MR263 through marker‐assisted backcrossing

Abstract BACKGROUND Blast caused by the fungus Magnaporthe oryzae is a significant disease threat to rice across the world and is especially prevalent in Malaysia. An elite, early‐maturing, high‐yielding Malaysian rice variety, MR263 , is susceptible to blast and was used as the recurrent parent in this study. To improve MR263 disease resistance, the Pongsu Seribu 1 rice variety was used as donor of the blast resistance Pi‐7(t) , Pi‐d(t)1 and Pir2‐3(t) genes and qLN2 quantitative trait locus ( QTL ). The objective was to introgress these blast resistance genes into the background of MR263 using marker‐assisted backcrossing with both foreground and background selection. RESULTS Improved MR263‐BR ‐3‐2, MR263‐BR ‐4‐3, MR263‐BR ‐13‐1 and MR263‐BR ‐26‐4 lines carrying the Pi‐7(t) , Pi‐d(t)1 and Pir2‐3(t) genes and qLN2 QTL were developed using the simple sequence repeat ( SSR ) markers RM5961 and RM263 (linked to the blast resistance genes and QTL ) for foreground selection and a collection of 65 polymorphic SSR markers for background selection in backcrossed and selfed generations. A background analysis revealed that the highest rate of recurrent parent genome recovery was 96.1% in MR263‐BR ‐4‐3 and 94.3% in MR263‐BR ‐3‐2. CONCLUSION The addition of blast resistance genes can be used to improve several Malaysian rice varieties to combat this major disease. © 2015 Society of Chemical Industry