Marker‐assisted breeding of <scp><i>Pi‐1</i></scp> and <scp><i>Piz‐5</i></scp> genes imparting resistance to rice blast in <scp>PRR</scp>78, restorer line of <scp>P</scp>usa <scp>RH</scp>‐10 <scp>B</scp>asmati rice hybrid

Abstract

Abstract Rice blast, caused by fungus M agnaporthe grisea, is a serious disease causing considerable economic damage worldwide. Best way to overcome disease is to breed for disease‐resistant cultivars/parental lines of hybrids. Pusa RH 10, first aromatic, fine‐grain rice hybrid released and cultivated extensively in India. Hybrid and its parental lines, P usa 6 A and PRR 78, are highly susceptible to blast. CO 39 pyramid carrying two dominant, broad‐spectrum blast‐resistance genes, viz. Pi‐1 and Piz‐5 , used as a donor parent to introgress these genes into PRR 78 using marker‐assisted backcrossing ( MABC ). Microsatellite markers RM 5926 and AP 5659‐5 tightly linked to Pi‐1 and Piz‐5 genes, respectively, were used for foreground selection to derive introgression lines. Further, these lines were evaluated for agronomic performance, disease reaction and cooking quality traits along with PRR 78. Most of the improved lines were on par with PRR 78 for all traits evaluated except gelatinization temperature. Recurrent parent genome percentage ( RPG ) study also revealed similarity of these lines with PRR 78. Hybrids derived using improved PRR 78 lines were superior over P usa RH 10 in terms of yield.