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20141
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Subject: Plant Breeding and Genetics × Author: Chaudhari, Prabharani × Start date: 1990 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Molecular Characterization of RILs derived from japonica x indica sub-species for yield attributing traits in rice (Oryza sativa l.)
    (JNKVV, 2014) Chaudhari, Prabharani; Mishra, D.K.
    ABSTRACT The present study entitled “Molecular characterization of RILs derived from japonica x indica sub-species for yield attributing traits in rice (Oryza sativa L.)” was carried out at Seed Breeding Farm, JNKVV, Jabalpur during the Kharif 2011 and Kharif 2012 with the objective to characterize RILs lines based on yield attributing traits, study genetics of yield attributing traits and to find out informative SSR primers (QTLs) for yield attributing traits. Rice (Oryza sativa L.) is central to the lives of billions of people around the world. It is an important cereal crop across the globe and India. The production and productivity of rice was significantly enhanced with the introduction and cultivation of semi-dwarf, fertilizer responsive and non-lodging high yielding varieties in the early seventies leading to the "Green Revolution". The yield level of high yielding varieties is plateauing in recent years. There is an urgent need to adopt some innovative technologies to break the yield ceiling in rice. Among the available technological options to enhance rice production and productivity, DNA markers have been one of them which are successfully used for screening plant genomes for quantitative trait loci (QTLs) controlling complex traits yield. The developments of molecular genetic linkage map for many species provide the foundation and tools for QTL mapping, marker-assisted breeding, physical mapping and map based cloning of gene. Development of various types of DNA markers by different techniques has provided a new platform for rice genome research. The present study was based on the characterize RILs lines based on yield and yield attributing traits and to find out informative SSR primers. It is evident from the above study that the morphological traits that the characters viz., seed husk colour, seed length, seed width, beak shape, plant habit, leaf colour, leaf width, collar colour, ligule colour, ligule length, auricle colour and panicle type had sufficient amount of variability. Hence, characterization of recombinant inbred lines can be based on these traits would be fruitful. Analysis of variance indicated presence of considerable variations in genotypes for all the traits studied therefore selection can be done on simple phenotypic performance. The high estimates of phenotypic and genotypic coefficients of variability, heritability and genetic advance were obtained for characters viz., total tillers per plant, number of filled spikelets per panicle, number of unfilled spikelets per panicle, total number of spikelets per panicle, grain yield per plant, panicle index and harvest index while it was moderately high and low for remaining traits revealed that there is considerable amount of genetic variability present in the population for these traits. High estimates of heritability coupled with high genetic advance for the above listed traits revealed that most likely the heritability is due to additive gene effects and that sufficient improvement in yield can be achieved through selection for these characters. The result of correlation and path analysis revealed that the traits such as panicle index, harvest index, culm height and biological yield per plant exhibited significant positive correlation with grain yield per plant as well as positive direct effect on grain yield per plant. Thus, it indicates true relationship between them and direct selection for these traits will be rewarding for yield improvement. However, among the traits having negative direct effect on grain yield per plant viz., plant height, total number of spikelets per panicle and days to maturity. Therefore, it indicates that the restricted selection model should be used for nullification of undesirable effect of these traits. Significant SSR - Marker QTL associations were exhibited by single marker analysis for yield and yield attributing traits in both the years and in pooled result. Out of 40 SSR polymorphic markers 28 and 26 markers showed associations for yield and yield attributing traits in first year and second year respectively, however 13 markers showed association in pooled result. The result of simple interval mapping a total of twenty three QTLs in first year, twenty one QTLs in second year and twenty four QTLs in pooled result were identified. The QTLs were mapped on chromosome 2, 3, 5, 7, 8, 10 and 11. Some QTLs are clustered in several chromosomal regions. Thirteen QTLs viz., qDTF 8-1, qTT 2-1, qTT 3-1, qTT 3-2, qTT 5-1, qTT 10-1, qTT 11-1, qFSN 2-1, qFSN 2-2, qTNS 2-1, qTNS 2-2, qTNS 7-1 and qTNS 8-1 were detected through simple interval mapping in both the years and in pooled result. It indicates that these QTLs are stable in this population but there is need to confirmation of these QTLs in different environments across multiple populations. Yield per plant QTL, qGY 8-1 were located in interval RM 25 - RM 447 on chromosome 8 with phenotypic variance R2 (62.99%) exhibited in pooled result . This locus affected flowering time, tillers number, number of spikelets and grain yield. In this case, this locus represent major gene. These QTLs can be directly applicable for marker assisted selection programme for yield enhancement by using of transgresive segregants. Quantitative trait loci (qGY 8-1) located on chromosome 8. This QTL can be directly applicable for marker assisted selection programme for yield enhancement by using of transgresive segregants (RILs). In this study RIL No. 77 and RIL No. 102 transgresive segregants for grain yield per plant, these lines should be directly used for varietal development programme and also use as parent for hybridization programme.