Genetik varyasyon ve populasyon yapısının Andricus lignicolus (Hartig, 1840)'da mitokondriyal DNA kullanılarak araştırılması

Oak taxa and gall-forming insect species, Andricus lignicolus, are parts of the Anatolian species diversity. Parthenogenetic generation galls of A. lignicolus are induced on the oak host as Q. robur, Q. petraea and Q. pubescens. In this thesis genetic variation, phylogenetic and phylogeographic structure and genetic differentiation among populations of A. lignicolus were investigated. For this purpose, mtDNA was isolated from 117 individuals from 15 populations, and a 433-bp region of mtDNA cytochrome b (cyt b) gene was amplified using PCR. After sequencing amplicons 18 specific haplotypes have been detected. Of the 58 characters showing variation, 21 were parsimony uninformative and 37 characters were parsimony informative, and there were several multiple hits. The nucleotide frequencies of A. lignicolus haplotypes were 34%, 11%, 9% and 44% for A, C, G and T, respectively. Among the variable sites, there were 30 transitions and 20 transversions (ti/ tv= 1.5). Average haplotype and nucleotide diversity were 0.32519 and 0.0087955, respectively. The highest haplotype diversity (h= 0.7778) was found in Kütahya population and the highest nucleotide diversity (?=0.042494) was estimated in Uşak population. Mismatch distribution analyses indicated that the studied A. lignicolus populations were in genetic equilibrium. Hierarchical F-statistics (AMOVA) were conducted for detecting hierarchical partitioning of molecular variation into researcher predefined?groups. Among several trials AMOVA analysis indicated highest and statistically the most significant variation being partitioned in each population (71.43% between each locality). Phylogenetic analyses were conducted through the application of maximum likelihood and maximum parsimony provided consensus trees that were similar in their topologies with two major clades supported with high bootstrap values. Bayesian analysis gave more polytomies in the obtained tree without major basal groupings of the haplotypes. Parsimony network analysis produced four haplogroups, of which the largest one covered half of the A. lignicolus haplotypes. Evaluated overall, findings of this thesis shed light into the genetic variation and population structure together with the intraspecific phylogeny of A. lignicolus species in Turkey.