The phylogenetic analysis of liquidambar Orientalis mill. varieties by comparing the non-coding trn regions of the chloroplast genome


Tezin Türü: Yüksek Lisans

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

Tezin Onay Tarihi: 2007

Öğrenci: MELİS OR

Danışman: ZEKİ KAYA

Özet:

Liquidambar L. genus are represented with four species in the world and one of these species, Turkish sweet gum (Liquidambar orientalis Miller) is naturally found only in southwestern Turkey with limited distribution in Muğla Province. The presence of increasing threats to its genetic resources signifies the importance of studying the phylogenetic relationships and genetic diversity in this relict endemic species. In this study, 18 different populations were sampled throughout the species range and noncoding transfer ribonucleic acid (trn) region of chloroplast DNA was studied to asses the phylogenetic relationships and genetic diversity. Experimental studies included the extraction of DNA, amplification and sequencing of the trn region of the chloroplast DNA. Molecular evolutionary analysis was done by using MEGA version 3.1 and Arlequin 2.000 softwares. Sequences from six other species of Liquidambar (L. styraciflua from USA, L. macrophylla from Mexico, L. formosana from Vietnam, L. acalycina from China, L. formosana from China and L. acalycina from USA) in the database were also included in the analysis. Moleculer diversity results show that population located in Muğla-Yatağan district has the highest number of polymorphic sites among the other populations of Turkish sweet gum. Population located in Marmaris-Günnücek has an average genetic distance value of 0.0032 within population, being the highest within the studied populations of Turkish sweet gum. The average genetic distance within variety orientalis (0.0011) was the greatest among all the varieties, but the most separated or divergent populations were members of variety integriloba. For both varieties and geographic groups, average diversity within was found to be the greatest portion (greater than 80%) of the total sequence diversity. The geographic groups located in Denizli and Muğla-Yatağan showed the highest average genetic distances within location, with a value of 0.0014. The genetic distance between the closest neighbor of Turkish sweet gum, American L. styraciflua was 0.0002, whereas the genetic distance between the most distant neighbors (Vietnamese L. formosana, Chinese L. acalycina and L. formosana) was 0.0051. Based on the molecular diversity analysis, seven populations were found to be important for conservation issues and two of them located in Marmaris have the highest priority. The most variant geographic groups are located in Denizli and Muğla-Yatağan districts. These populations could be considered as good candidates for future in-situ or ex-situ conservation programs.