Cynips quercusfolii'nin (Hymenoptera:Cynipidae) filogenetik analizi ve filocoğrafik yapısının mtDNA ve nDNA sekans yoluyla araştırılması

Cynips quercusfolii (Hymenoptera: Cynipidae) is a widespread oak gall wasp species distributed in the Palearctic region including Turkey. Individuals reared from asexual generation galls of the species were used to: i) reveal genetic variation present in the Turkish populations of C. quercusfolii, ii) search for the geographic structuring of the genetic diversity, iii) assess population demographic structure by exposing population expansion/retractions, iv) reconstruct phylogenetic and phylogeographic structure, v) test if the geographic barriers shaped phylogeographic and phylogenetic structure of the species, vi) effects of the climatic fluctuations on the genetic structure of the species, and vii) estimate times of divergence between major lineages of the species. For these purposes, a 433 bp fragment of mitochondrial DNA cytochrome b gene and the entire ITS2 region nuclear DNA were amplified and sequenced from 294 individuals representing 38 populations of C. quercusfolii. All sequences generated 125 mtDNA haplotypes and 30 ITS2 alleles. Haplotype/allele and nucleotide diversity estimates indicated the existence of high genetic variation in the Turkish populations. Nonetheless, lower nucleotide diversity versus higher haplotype diversity implied that populations have gone through some population expansion and retraction in the past. Phylogenetic and phylogeographic analyses through preforming maximum parsimony, maximum likelihood, and Bayesian approaches indicated that there is geographic structuring of the haplotypes considering the location of major barriers. Employing conventional molecular clock to the cytochrome b gene data to estimate times of divergence showed that C. quercusfolii split from the outgroup species in the Pliocene epoch, and during the Pleistocene climatic and environmental fluctuations played a key role in the structuring of the major clades and subclades. Overall, current findings of this thesis demonstrate that climatic oscillations and geographic barriers have left their imprints on C. quercusfolii in Turkey.