Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Development of Single Nucleotide Polymorphism Markers Using Genotyping by Sequencing Technique for Determination of Genetic Diversity and Population Structure in Hazelnut(01. Izmir Institute of Technology, 2021) Doğanlar, Sami; Doğanlar, Sami; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of TechnologyHazelnut (Corylus avellana L.) is a critical commodity for Turkey due to its economic and nutritional value. Turkey ranks first in world hazelnut production with 65-75% of the market. Due to the signifacance of this crop, it is crucial to preserve Turkish hazelnut genetic diversity. In the current study, a panel representing the entire national collection of 430 accessions was used. Genetic characterization of the panel revealed 7609 high-quality SNPs, 5567 of which were physically mapped to the Tombul reference genome. Fingerprint analysis indicated that all individuals could be distinguished with only seven SNP markers. Population structure analysis of the dataset indicated that the panel's genetic relationships were explained by three clusters containing 8, 17, and 25 accessions, respectively. Nearly half of the accessions had admixed ancestry. The admixed material contained 8 cultivars, 22 landraces, and 12 wild accessions indicating that nearly 50% of each type of material had admixed ancestry. An unweighted neighbor-joining dendrogram was constructed using a distance matrix computed with the identity by state distance measure. The calculated dissimilarity values ranged from 0.15 to 0.30 with a mean of 0.26. This study is the first time that the Gras-Di sequencing approach was used on a nut tree and provides a new perspective on hazelnut genetics. In addition, the panel will serve as a wellcharacterized genetic resource for future work on this economically important tree nut crop.Master Thesis Association Mapping for Oil and Protein Content in Hazelnut (corylus Avellana L.)(Izmir Institute of Technology, 2020) Doğanlar, Sami; Doğanlar, Sami; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of TechnologyEuropean hazelnut has an important place in terms of nutritional and economic value among tree nut species. Because of its nutritional content, the consumption of hazelnuts promotes human health in many ways. These nutritional components are controlled by multiple genes and affected by the environment; therefore, they are quantitative traits. The vast majority of world hazelnut production is provided by Turkey. So it is important to develop hazelnuts with higher nutritional quality for our country. In this work, we aimed to associate genetic diversity data and oil and protein content of hazelnuts to identify QTL. For this purpose oil and protein content were measured in kernels of 96 accessions. Genotypic data were obtained with 30 SSR markers and resulted in 407 polymorphic alleles. According to allelic data, the mean dissimilarity value was 0.52 (52%) for the 96 accessions. Population structure analysis resulted in three clusters with 30, 30, and 16 accessions. Twenty accessions could not be assigned to any cluster and were considered admixed. Association mapping between allelic and phenotypic data indicated that five loci were significantly associated with oil content. The most significant result for oil content belonged to B628-307 loci (p=0.0002, r2=0.145). Three loci were detected for protein content. Among them, A613-153 had the most significant effect (p=0.003, r2= 0.088). We hope that our survey of germplasm and the identified loci associated with oil and protein amount can accelerate hazelnut breeding. In the future this study can contribute to develop new genotypes with enhanced nutritional value.