Molecular Biology and Genetics / Moleküler Biyoloji ve Genetik
Permanent URI for this collectionhttps://hdl.handle.net/11147/9
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Article Citation - WoS: 7Citation - Scopus: 10Association Mapping of Agro-Morphological Traits in European Hazelnut (corylus Avellana)(Springer, 2019) Frary, Amy; Öztürk, Süleyman Can; Balık, Hüseyin İrfan; Balık, Selda Kayalak; Kızılcı, Gökhan; Doğanlar, Sami; Frary, AnneMore than half of European hazelnut (Corylus avellana) production occurs in Turkey. Despite this dominance, the yield of Turkish cultivars has remained stagnant over the past 10years with Italian yield nearly double that in Turkey. This difference is due to Turkey's unique cultivation system; hazelnuts are grown in bushy clusters (ocak system), not as single trees. Current hazelnut breeding efforts are shifting toward the development of materials for single plant orchards which are much higher yielding; thus, there is a need to explore germplasm for relevant agro-morphological traits and to determine their genetic control. The objectives of this study were to examine data for 44 such traits in 390 hazelnut accessions: 16 cultivars, 232 landraces and 142 wild individuals from nine provinces in Turkey and to map the loci associated with these characteristics using simple sequence repeat markers. Comparison of cultivars, landraces and wild hazelnut accessions revealed the effects of domestication and selection on the crop and indicated that useful alleles for traits such as cropping and reduced alternate bearing may exist in the wild germplasm. A total of 145 quantitative trait loci (QTL) were detected with the largest proportions identified for involucre (26%) and inflorescence (14%) morphology. Several markers co-localized with more than one trait including markers for male catkin abundance which were shared with plant vigor and height. Similarly, markers for female flower abundance co-localized with suckering and alternate bearing. Such markers and their linked QTL should be studied in more detail as they might help breeders select for plant vigor, decreased suckering and increased flower production: traits which will be extremely useful for Turkey's transition to single plant orchards.Article Citation - WoS: 10Citation - Scopus: 13Analysis of European Hazelnut (corylus Avellana) Reveals Loci for Cultivar Improvement and the Effects of Domestication and Selection on Nut and Kernel Traits(Springer Verlag, 2019) Frary, Amy; Öztürk, Süleyman Can; Balık, Hüseyin İrfan; Kayalak Balık, Selda; Kızılcı, Gökhan; Doğanlar, Sami; Frary, AnneTurkey is a rich source of European hazelnut (Corylus avellana) germplasm with nearly 400 accessions in the national collection. This genetic material encompasses cultivars, landraces and wild genotypes which were characterized for 12 nut and 13 kernel traits over 2years in the 1990s. Analysis of these attributes revealed both the positive and negative impacts that human selection and breeding have had on hazelnut. Thus, while selection has resulted in larger nuts and kernels, cultivars have fewer nuts per cluster and kernels with larger internal cavities. Breeding has also resulted in a propensity for cultivars to have higher proportions of double kernels and empty nuts, two traits which reduce quality and yield. In addition, it is clear that while selection has successfully increased hazelnut fat content it has not impacted overall flavor, a much more complex trait. The nut and kernel phenotypic data were combined with genotypic data from 406 simple sequence repeat marker alleles for association mapping of the quantitative trait loci (QTL) for the traits. A total of 78 loci were detected in the population with the highest proportions for nut (24%) and kernel (26%) appearance parameters followed by quality (19%), shell thickness (16%) and yield-related (15%) traits. It is hoped that some of the identified QTL will be useful for future breeding of hazelnut for improved nut and kernel yield and quality.Article Citation - WoS: 17Citation - Scopus: 20Molecular Genetic Diversity of the Turkish National Hazelnut Collection and Selection of a Core Set(Springer Verlag, 2017) Öztürk, Süleyman Can; Balık, Hüseyin İrfan; Kayalak Balık, Selda; Kızılcı, Gökhan; Duyar, Ömür; Doğanlar, Sami; Frary, AnneEuropean hazelnut (Corylus avellana L.) is an economically and nutritionally important nut crop with wild and cultivated populations found throughout Europe and in parts of Asia. This study examined the molecular genetic diversity and population structure of 402 genotypes including 143 wild individuals, 239 landraces, and 20 cultivars from the Turkish national hazelnut collection using simple sequence repeat (SSR) markers. A total of 30 SSR markers yielded 407 polymorphic fragments. Diversity analysis of the Turkish hazelnut genotypes indicated that they fell into three subpopulations according to ad hoc statistics and neighbor-joining algorithm. Although all cultivars clustered together, they overlapped with the wild accessions and landraces. Thus, the dendrogram, principal coordinate, and population structure analyses suggest that they share the same gene pool. A total of 78 accessions were selected as a core set to encompass the molecular genetic and morphological diversity present in the national collection. This core set should have priority in preservation efforts and in trait characterization.Article Citation - WoS: 30Citation - Scopus: 36Molecular Genetic Diversity and Association Mapping of Nut and Kernel Traits in Slovenian Hazelnut (corylus Avellana) Germplasm(Springer Verlag, 2017) Öztürk, Süleyman Can; Öztürk, Saniye Elvan; Çelik, İbrahim; Stampar, Franci; Veberic, Robert; Doğanlar, Sami; Solar, Anita; Frary, AnneEuropean hazelnut (Corylus avellana L.), cultivated in several areas of the world including Europe, Anatolia, and the USA, is an economically important nut crop due to its high mineral, oleic acid, amino acid, and phenolic compound content and pleasant flavor. This study examined molecular genetic diversity and population structure of 54 wild accessions and 48 cultivars from the Slovenian national hazelnut collection using amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers. Eleven AFLP primer combinations and 49 SSR markers yielded 532 and 504 polymorphic fragments, respectively. As expected for a wind-pollinated, self-incompatible species, levels of genetic diversity were high with cultivars and wild accessions having mean dissimilarity values of 0.50 and 0.60, respectively. In general, cultivars and wild accessions clustered separately in dendrogram, principal coordinate, and population structure analyses with regional clustering of the wild material. The accessions were also characterized for ten nut and seven kernel traits and some wild accessions were shown to have breeding potential. Morphological principal component analysis showed distinct clustering of cultivars and wild accessions. An association mapping panel composed of 64 hazelnut cultivars and wild accessions had considerable variation for the nut and kernel quality traits. Morphological and molecular data were associated to identify markers controlling the traits. In all, 49 SSR markers were significantly associated with nut and kernel traits [P < 0.0001 and LD value (r2) = 0.15–0.50]. This work is the first use of association mapping in hazelnut and has identified molecular markers associated with important quality parameters in this important nut crop.