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QTL MAPPING FOR YIELD AND ITS COMPONENT TRAITS IN BASMATI RICE (ORYZA SATIVA L.)
| Content Provider | KrishiKosh-Indian National Agricultural Research System |
|---|---|
| Advisor | Singh, A. K. |
| Researcher | Bagati, Sreshti |
| Abstract | Rice (Oryza sativa L.), a monocotyledonous angiosperm, is consumed as a potent staple food by billions of people across the globe. With the increase in the global population, the demand for rice will continue to grow in the coming years. Hence, the major thrust of the rice producing nations is on increasing the yield efficiency of various rice varieties. In recent years, detection and mapping of the quantitative trait loci (QTL's) for yield and its component traits has been looked upon as an efficient way of improving the yield potential of rice varieties. The present study was conducted during Kharif 2014 and 2015 at Research Farm of SKUAST- Jammu and Molecular Laboratory of Rice, School of Biotechnology, Sher-e-Kashmir University of Agricultural Sciences and Technology, Chatha, Jammu with the aim of carrying out the phenotypic and genotypic evaluation of the Recombinant inbred line (RIL) population along with the identification of the QTL's associated to yield and its component traits. The material used in the study comprised of the parents (Basmati 370 and Pusa Basmati 1) and a RIL population comprising of 140 lines derived from a cross between them. Phenotypic evaluation of the population was carried out in a randomized block design with three replications. A total of 314 trait- specific SSR markers were used for genotyping of the population. Linkage map construction was carried out using MAPMAKER/EXP (version 3.0b) and for the identification of QTLs composite interval mapping (CIM) was done using WinQTL Cartographer (version 2.5). The mean values of the traits i.e. effective tillers per plant, panicle length, grain number per panicle, 1000- grain weight, yield per plant and spikelet fertility percentage obtained during the year 2014, 2015 and for 2014-15 (pooled data) were 8.81, 26.61cm, 101.89, 22.15g, 15.85g, 86.94 per cent; 9.97, 26.46cm, 95.42, 22.51g, 9.67g, 84.64 per cent; 9.56, 26.46cm, 98.69, 22.42g, 12.73g and 85.62 per cent, respectively. Correlation studies showed that various components of yield show a significant positive relationship with yield. The mean values and the character wise frequency distribution of RIL's observed for yield and its associated traits during 2014, 2015 and for 2014-15 (pooled) suggest that the characters studied are of quantitative inheritance. Out of 314 markers, 89 SSR markers showed polymorphism with respect to parents and hence were used for RIL genotyping. Further, 5 linkage groups obtained from MAPMAKER software were assigned to 12 chromosomes. The mean values of the phenotypic data along with the genotypic data and the completed linkage map provided the basis for QTL detection. 8 QTLs were identified during the year 2014 which include, 2 QTLs for the number of effective tillers per plant located on chromosome 4 (qET4 at 2.0cM; Marker interval: RM5709- RM317) and 9 (qET9 at 0.0; Peak Marker: RM160) explaining the phenotype by 20.83 per cent, 1 QTL for panicle length located on chromosome 5, 1 QTL for yield per plant on chromosome 9, 3 QTLs for grain number per panicle (2 on chromosome 1 and 1 on chromosome 4) and 1 QTL on chromosome 1 for spikelet fertility percentage. During the year 2015, 14 QTLs were identified including, 2 QTLs for the number of effective tillers per plant located on chromosome 3 (qET3.1at 100.2 cM; Marker interval: RM3513- RM3698 and qET3.2 at 131.9 cM lying in between RM 3698- RM16) which explained 57.89 per cent of the phenotype, 2 QTLs for panicle length located on chromosome 8 and 9, 6 QTLs for yield per plant on chromosome 2, 3, 4 and 5, 2 QTLs for grain number per panicle on chromosome 7 and 10 and 1 QTL on chromosome 5 for spikelet fertility percentage (qSF5). In 2014-15 (pooled), 9 QTLs were identified, 2 for panicle length located on chromosome 8 (qPL8 at 48.6 cM; Marker interval: RM556- RM3644) and 9 (qPL9 at 169.5 cM, flanked by markers RM245 and RMl 126). Together they explained 31.78 per cent of the phenotypic variation. Out of the 9, 5 QTLs located on chromosomes 1, 4, 5 and 7 were found to be associated with grain number per plant. 2 QTLs on chromosome 5 related to spikelet fertility percentage. The variation in the number of QTL's detected during two successive years, indicate that the traits are affected by the environment and hence confirm their quantitative nature. The QTLs qGNPl. 1. qGNPl.2. qPL8. qPL9, qET3.1, qET3.2, qYPP3, qYPP9, qSFS.I and qSF2 identified in the present study are quite stable which is understood from their accounting for high percentage of phenotypic variation explained and LOD scores. These major as well as stable QTLs related to yield and its various components identified in the present study offer opportunities for progressive grain yield improvement in rice through various approaches viz., by carrying out marker- assisted selection (MAS) and map- based cloning. QTL qPL5 for panicle length located at 0.7 cM on chromosome 5 and QTL qGW11 for 1000- grain weight located at 0.0 cM on chromosome 1 may prove enormously useful for improving the yield related traits in rice. Further, fine mapping of QTLs can be done to achieve more precision and it may allow detection of QTLs with smaller effects which may prove useful for the development of reliable markers for marker assisted selection Keywords: Quantitative trait loci, SSR markers, linkage, Composite interval mapping, Recombinant inbred line. |
| Page Count | 187 |
| File Size | 19321330 |
| File Format | |
| Language | English |
| Publisher | Sher-e-Kashmir University of Agricultural Sciences and Technology |
| Publisher Place | Jammu |
| Access Restriction | Open |
| Subject Keyword | Oryza Sativa L Composite Interval Mapping Cultivation Germplasm Evaluation Plant Breeding Qtl Mapping For Yield and Its Component Traits In Basmati Rice (oryza Sativa L.) Biotechnology |
| Content Type | Text |
| Educational Degree | Doctor of Philosophy (Ph.D.) |
| Resource Type | Thesis |
