Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Characterization of Peppers for Antioxidant Content and Virus Resistance(Izmir Institute of Technology, 2008) Keçeli, Mehmet Ali; Doğanlar, SamiIn the first part of this study, total water soluble antioxidant activity, phenolic compounds and vitamin C content of 29 Turkish and 14 non-Turkish pepper cultivars were determined. Significant trait diversity was found in the cultivars with the most variation (7.4-fold) seen for total antioxidant capacity which ranged from 2565 to 18957 .mol Trolox/kg. Vitamin C content for the peppers ranged from 522 to 1631 mg/kg, a 3.1-fold difference, while total phenolic content for the pepper cultivars ranged from 607 to 2724 mg/kg, a 4.5-fold difference. A strong correlation between total antioxidant capacity and phenolic content (r . 0.71) was also seen. Significant variation for antioxidant content in Turkish germplasm indicates that this material can be used for improvement and genetic mapping of nutritional content in pepper. In the second part of this study, amplified fragment length polymorphism (AFLP), cleaved amplified polymorphism (CAPs) and simple sequence repeat (SSR) markers were used to map gene(s) for cucumber mosaic virus resistance. The mapping was conducted using a F2 population derived from a cross between Capsicum annuum cv. Jupiter (susceptible) X C. frutescens (resistant). The F2 population, consisting of 76 individuals, was screened with 13 AFLP primer pairs, 60 CAPs markers and 30 SSR markers to detect markers possibly linked to CMV resistance gene(s). As a result, 7 QTL were found which are related with resistance to CMV in pepper. This will provide pepper breeders an opportunity to use these markers for marker-assisted selection for CMV resistance in pepper.Master Thesis Quatitative Trait Loci Analysis(qtl) of Fruit Characteristics in Tomato(Izmir Institute of Technology, 2008) Ökmen, Bilal; Doğanlar, SamiTomato has a crucial part in the human diet. Therefore, many plant breeders have tried to improve horticulturally important traits such as yield, fruit size, shape and color. With increased attention on human health, plant breeders also consider the improvement of health-related traits of fruits and vegetables such as antioxidant characters. However, because most plant traits are controlled by more than one gene, improvement of crops that possess the desired traits is very difficult.Development of molecular marker techniques makes these processes feasible for plant breeders. In this study both health-related and horticulturally important traits were characterized for identificaton of their locations in the tomato genome using 152 Lycopersicon hirsutum BC2F2 mapping individuals. For this aim, all plants were phenotypically and genotypically characterized. It was expected that some alleles from the wild species L.hirsutum had the capacity for improvement of both antioxidant and agronomically important traits of elite lines.A total of 75 QTLs were identified for all traits. Of the 75 QTLs, 28 were identified for five antioxidant traits including total water soluble antioxidant capacity, vitamin C, phenolic, flavonoids and lycopene content and 47 QTLs were identified for 8 agronomic traits including external and internal fruit color, fruit weight, firmness, fruit shape, stem scar size, locule number and wall thickness. Seventeen of these QTLs were also identified by previous studies. Markers linked with these QTLs can be used in Marker Assisted Selection (MAS) for improvement of elite tomato lines.Master Thesis Characterization and Genetic Mapping of Health Related Traits in Tomato(İzmir Institute of Technology, 2005) Rusçuklu, Dane; Doğanlar, SamiTomato is consumed in the daily diet and has a diverse nutritional content including antioxidants, lycopene, vitamin C and phenolics. However, the content of these compounds in tomato cultivars could be higher. There are two ways of increasing the nutritional quality of tomato. One of them is a transgenic way which is still questioned and is not approved in many countries. The other way is molecular breeding which is based on introgression of wild genes into cultivated tomatoes via the combination of classical breeding with molecular marker analysis. This method lets us obtain nontransgenic tomatoes with increased nutritional quality. In this project a population that was obtained from a cross between wild type L.pimpinellifolium and cultivated tomato L.esculentum was used. This population includes 145 inbred backcross lines (IBLs). It was expected that some individuals of this population had increased nutritional quality derived from the wild parent. In order to test this hypothesis, antioxidant activity of each line was measured. The method used to measure antioxidant activity was based on spectrophotometric measurement which gave mol Trolox equivalent antioxidant activity. It was observed that the IBLs were phenotypically close to L.esculentum and that some individuals did have higher antioxidant activity than the cultivated parent. The population was also mapped with molecular markers and 31 possible QTLs which control antioxidants in tomato were found. The source of alleles associated with increased antioxidant characters was usually L.pimpinellifolium. This result confirmed that wild type tomatoes can be a resource for increasing nutritional quality of tomatoes.