Improving Hybrid Rice Parental Lines for Blast Resistance by Introgression of Broad‐spectrum Resistance Genes Pi54 and Pi9 by Marker‐assisted Selection

Hybrid rice technology offers a great promise to produce 15% to 20% more yield than pure line varieties. The success of hybrid rice hinges on developing superior parental lines. To improve the blast resistance of hybrid rice parental line RP5933-1-19-2R, crosses were made with donors of two major blast resistance genes namely, Pi54 (Tetep) and Pi9 (IR71033-121-15) and the resulting F(1)s were confirmed for their hybridity by using Pi54MAS and NMSMPi9-1 genic markers. The confirmed F(1)s were intercrossed to obtain ICF(1)s and selected positive plants by markers were backcrossed to the recurrent parent, as well as selfed for advancing further to BC1F3 and ICF4 generations. The segregating plants were phenotyped for blast resistance at Uniform Blast Nursery. The identified complete restorers namely, RP 6619-1, RP 6616-26, RP 6619-3 and RP 6619-11 with Pi9 and Pi54 genes would serve as donors for broad spectrum blast resistance. This could ultimately lead to the development of new rice hybrids with improved resistance to blast disease, which is crucial for sustainable rice production and food security.