Shivakumar, N.SHILPA, H. B.2017-07-142017-07-142014-11-10Th-10969http://krishikosh.egranth.ac.in/handle/1/5810025263The present investigation was carried out to transfer major resistance gene Pil conferring resistance to blast (Magnaporthe grisea L.) and bph4 for brown planthopper (BPH, Nilaparvata lugens Stal.) in the genetic background of rice cultivar Jaya through marker-assisted backcross breeding at Zonal Agricultural Research Station, V. C. Farm, Mandya from 2011-2014. The donors ClOlLAC for blast and CR271 l -76 for BPH resistance were crossed with Jaya and the F 1s derived were identified through polymorphic markers. Selected F 1 s were backcrossed with Jaya to raise BC1 F 1, BC2F 1, BC3F1 (separate transfer crosses i. e., Jaya x ClOlLAC and Jaya x CR2711-76) and intercrossed to obtain TC-F2s [(Jaya x ClOlLAC) X (Jaya x CR2711-76)]. The BC 1 F 1s were also selfed to develop segregating BC 1F2 populations. Marker analysis of 101 BC 1F2 plants from (Jaya x ClOlLAC) X Jaya cross, using RM224 marker yielded 32 plants having Pil gene while, from 112 BC 1 F2 plants of (Jaya x CR2711-76) X Jaya cross evaluated, using RM586 and RM589 markers for bph4 gene, 57 plants were found to be homozygous. Out of 111 TC-F2s, 30 plants selected genotypically and 33 phenotypically, had Pil gene. Thirty three pyramided progenies with Pil and 44 with bph4 gene were identified after genotypic and phenotypic evaluation of BC 1 F2s. Totally ten plants having both Pil and bph4 genes were selected. Among them, eight have showed better grain yield/plant (-21.08 g) compared to Jaya (13 g). Plant number 13, 14, 24, 31, 49, 86 and 109 were early to flower (89-99 days) compared to Jaya (11 Odays ). They recorded higher number of filled grains/panicle (58.2-101.67) and spikelet fertility (55.68-64.38%) as compared to Jaya (51.8 and 24.98%). Among the three markers validated, RM224 for blast and RM586 for BPH showed significant association with the pyramided genes.ennullThesis