Mohanty, I. C.Behera, Sanjib KumarRout, G. R.Panda, S.Bastia, D.N.2022-02-012022-02-012020https://krishikosh.egranth.ac.in/handle/1/5810181504TH - 6122Rice (Oryza sativa L) having chromosome no. 24 belongs to the family poaceae (Gramineae), sub family Bamboosoideae and tribe Oryzeae.It is an Asian originated ,widely important and staple diet of more than fifty percent people of the world, but there are so many biotic and abiotic factors that cause the reduction of the yield of the rice. Among the abiotic stresses iron toxicity is a main problem. Iron toxicity is mainly seen in the water logged area and generally causes 15-30% yield reduction but sometimes it may be severe and cause the entire crop loss in the harsh toxicity at the younger stage. Though there are many methods to control the iron toxicity, advancement of the new variety with tolerance to iron toxicity is the most likely-looking process. Development of the tolerant genotypes using the transgenic methods is a headway process but it is highly denounced due to the biosafety affair. Cis-genic breeding involving introgression of a particular desired trait followed by marker assisted selection is therefore a break-through process for development of high yielding Fe tolerant varieties. Therefore, identifying a closely linked marker that is associated with the trait is the matter of concern. In this research 102 germplasm which include land races and high yielding varieties were grown in the hotspots for the phenotypic assessment regarding the iron toxicity in the regional research and technology transfer station (RRTTS) OUAT, Bhubaneswar. Different parameters were taken for the morphological screening of the total 102 germplasm of the control and toxicity plot each in the two block manners. These phenotypic parameters included the leaf bronzing index (LBI), 50% flowering, number of tillers/ hills, 50% days of panicle initiation, plant height, panicle length, total number of grains/ panicles, 1000 grain weight and yield. The analysis of variance was calculated was calculated and CV % and CD at (5%) was also calculated. Basing upon the average leaf bronzing score it was revealed that their different kinds of plants like highly tolerant, moderately tolerant, tolerant, susceptible and moderately susceptible there. From the previous study and also from this year it was found Swarna, Ganjamgedi Haribhoga, Mashuri, were tolerant to iron toxicity and Hasant, Pratikshya, Pooja, were high yielders but susceptible to iron toxicity. An introgression programme was developed by choosing Hasant and Pratikshya as the female parents and Swarna as the male parents. The F1 seeds thus obtained were again sown in the pot to get F1 plants and from which the genetic analysis could be done and the hybridity test can be conformed using the markers like RM144, RM 456, RM 7102, OsNRAMP5b, RM 217 that would be validated to give contrasting band after PCR reaction previously.EnglishThesis