Marker assisted introgression of genes governing resistance to bacterial blight and blast diseases into an elite Basmati rice variety, ‘Pusa Basmati 1509’

Abstract

In the present study, we introgressed two genes each governing resistance to major diseases of rice namely, bacterial blight (BB) (xa13 and Xa21) and blast (Pi2 and Pi54) into a popular Basmati cultivar, Pusa Basmati 1509 (PB 1509) through marker assisted backcross breeding (MABB). Through foreground selection, seven plants homozygous for all the four genes were selected from a large population of 1832 BC2F2 plants and subjected to background selection coupled with phenotypic selection for agronomic and grain quality traits of the recurrent parent. BC2F2 selections were further advanced to BC2F4 generation to develop near-isogenic lines (NILs). Six NILs from the BC2F4 families with an RPG recovery ranging from 82.5% to 90.5% were evaluated in multi-location trials for agronomic performance, grain quality traits and disease resistance. The level of resistance to BB and blast diseases in all the selected NILs was similar to that of the donor parent. Three BB races, race 2, 4 and 6, respectively produced on average 1.8, 2.3 and 2.5 cm of lesion length in the NILs as against 15.6, 18.1 and 20.8 cm in PB1509. Further, the NILs recorded a disease score of 1.0 and 1.7 for two blast isolates Mo-nwi-38 and Mo-nwi-kas, respectively, as against the score of 4.0 in PB 1509 for both the isolates. The NILs were similar to PB 1509 for major agronomic and grain quality traits with the advantage of resistance to BB and blast diseases.