Kapoor, RahulGagandeep Kaur2020-10-012020-10-012020Gagandeep Kaur (2020). Identification of quantitative trait loci (QTLs) for β-glucan in oat (Avena sativa L.) (Unpublished Ph.D. Dissertation). Punjab Agricultural University, Ludhiana, Punjab, India.https://krishikosh.egranth.ac.in/handle/1/5810152172Characterization of germplasm resources is needed to facilitate its use in plant breeding and in research. In the present study, morphological traits and molecular marker methods were used to assess the genetic diversity among 96 oat genotypes. Analysis of variance showed a significant variation among all the genotypes for morphological traits. Based on squared Euclidean distance, all genotypes were divided into 10 different clusters. The best genotypes for dual purpose were IC 372493, EC 537815, P 7 295932, EC 537856, IC 372529, IC 37248, EC 246179, EC 537834, EC 209524, EC 528888, EC 537924, IC 372478, EC 246200. Ninety two SSR markers were used for diversity analysis, these revealed high level of polymorphism, detecting 250 alleles. Diversity analysis was evaluated using DARwin. The dissimilarity values ranged from 0.33 to 0.79 signifying a moderate degree of dissimilarity among the A. sativa accessions evaluated. As our major goal in this research project was to find the QTLs for β glucan content, so we needed the contrasting parents for β glucan content in that case. The best genotypes for higher β glucan content were OL 10, EC 237851, EC246158, EC 528874, EC 372463. The F2:4 mapping population consisting of 91 lines was developed from the cross between OL10 (5.8 %) and OL11 (0.8 %). On phenotypic evaluation, the values of β glucan content in the population ranged from 1.05% to 6.08%. Out of 231 markers, 25 were found to be polymorphic between the two parents and were used to genotype the mapping population. Using MAPDISTO with LOD score of 3.0 and recombination fraction of 0.3, four linkage groups were generated. QTL cartographer with single marker analysis (SMA) and composite interval mapping (CIM) were used to identify the QTLs associated with beta glucan content. QTL region was mapped on LG 1 and with LOD score 3.7, explaining the phenotypic variance of 31% and Second QTL region was mapped on LG 4 with LOD score of 4.3 and explaining the phenotypic variance of 33%. Further, fine mapping of putative QTL will facilitate the eventual identification of genes contributing to β-glucan content.ennullThesis