Pattern of genetic diversity in Turkey oak (Quercus cerris L.) populations


Tezin Türü: Doktora

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Biyolojik Bilimler Bölümü, Türkiye

Tezin Onay Tarihi: 2014

Öğrenci: YELİZ TÜMBİLEN ÖZER

Danışman: ZEKİ KAYA

Özet:

Quercus cerris L. is a native and widely distributed species in Turkey. It is an important element of Anatolian forests and with other oak species constitute 76.4% of broadleafed forests. However, there is little information on the genetic make-up of Turkish populations. In the current study, the genetic diversity of Q. cerris populations sampled within their natural range is assessed with microsatellite loci (SSRs) polymorphism. Thirteen populations were sampled from seven different locations. Four of these are rich in different oak species coexisting and possibly hybridizing. To estimate population genetic diversity parameters, twelve microsatellite primers were applied to 172 Q. cerris genotypes and 47 suspected hybrid genotypes. All genetic analysis were carried out in duplicate. Also, in order to evaluate the genetic proximity between Q. cerris and other oaks with suspected hybrid genotypes, Principle Component Analysis (PCA) were conducted for different regions. It was found that the highest molecular diversity was detected in Kahramanmaraş-Adıyaman region’s populations. The populations that had the least genetical diversity were from Kastamonu and Ankara. According to the UPGMA dendrogram results, two major clusters were defined. One of them was composed of Kastamonu-Ankara populations while the other cluster had the rest of the studied populations. When the most probable number of populations (K) was estimated, it was found to be two for just Q. cerris genotypes and nine for Q. cerris genotypes analyzed with 47 suspected hybrid genotypes. For nine clusters, Kahramanmaraş-Adıyaman populations and Kastamonu-Ankara populations formed big clusters as the rest formed their individual clusters. Among suspected hybrid genotypes, except six of them, all was inferred to have certain type of populational genomic composition with a minimum 0.93 membership of coefficient for these populations. Among six, four of them had coefficients less than 0.80 and membership of two or three populations. As a result of this study, pattern of genetic diversity in Turkey oak obtained for the first time. This genetic information will be useful for establishing principles for conservation and management of genetic resources of the species since most of Turkey oak dispersion ranges are faced with a serious degradation rates.