Identification and molecular characterization of high-yielding, blast resistant lines derived from Oryza rufipogon Griff. in the background of ‘Samba Mahsuri’ rice

The wild species of rice, Oryza rufipogon, is a source of genetic variation for yield-enhancing traits and blast resistance. With the objective to genetically enhance the elite rice cultivar, ‘Samba Mahsuri’, a set of 192 BC2F2 and BC2F3 lines developed from O. rufipogon was characterized for yield-enhancing traits and blast resistance. The study revealed the presence of significant genetic variability and transgressive segregation for productive tillers, spikelets per panicle, and grain yield per plant. The study also identified several introgression lines superior to the recurrent parent for yield enhancing traits and blast resistance. Molecular characterization of 26 blast resistant lines identified multiple blast resistance genes in IL-136 [Pib, Pi9 (t), Pi54, Pi38, Pitp and Pi20(t)], IL-3 [Pib, Pi54, Pi38, Pitp and Pi20(t)], and IL-140 [Pib, Pi9(t), Pi54, Pi38, and Pitp]. Based on the performance of yield-enhancing traits and blast resistance, seven lines (IL-27, IL-28, IL-29, IL-72, IL-139, IL-158 and IL-171) showed merit. Estimation of the recovery of the recurrent parental genome by using 117 polymorphic SSR markers revealed that recurrent-parental genome recovery varied from 54.0 (IL-158) to 92.3% (IL-27). These promising, high-yielding introgression lines with multiple blast-resistance genes can serve as important genetic resources for yield and blast resistance improvement in rice, especially for the southern India.