Genetic structure and differentiation of natural populations of the olive fruit fly, Bactrocera oleae
Agricultural University of Athens, Department of Agricultural Biotechnology
Genetics Section, Genetics Laboratory
Master’s Thesis: Genetic Structure and Differentiation of Natural Populations of the Olive Fruit Fly, Bactrocera oleae.
Postgraduate Programme in ‘Biotechnology and Applications in Agriculture’
Vasiliki Androutsopoulou, Athens, November 2011
Abstract
In the present study, natural populations of the olive fruit fly, Bactrocera oleae, using the starch gel electrophoresis method, with the aim of detecting polymorphism in four enzymes, encoded by four corresponding genes, which are of particular significance and interest for the genetics, morphology and physiology of the olive fruit fly. The results of the study could prove useful: (a) in understanding the factors that shape the genetic structure and differentiation of natural populations of the olive fruit fly in the study areas, b) in improving methods for controlling the olive fruit fly; and c) in drawing conclusions regarding its dispersal from its place of origin in Europe.
Wild populations of the olive fruit fly were collected from areas within Greece as well as from countries in the Mediterranean basin, the olive fruit fly’s primary range, and the enzymes alcohol dehydrogenase (ADH), 6-phosphogluconate dehydrogenase (6-PGD), phosphoglycomutase (PGM) and α-glycerophosphate dehydrogenase (α-GPDH).
In all populations and for all four enzymes, the alleles of each gene in each population exhibit similar frequencies and the same ranking order based on their frequencies. These findings suggest the influence of selective pressures on natural populations, because the phenomenon of random genetic drift, which is expected to act in small populations, cannot, on its own, explain the results, nor can gene flow (via migration), given the geographical distance between the populations under study.
Furthermore, the detection of rare alleles and the variation in the genetic structure of the wild populations in Spain and Cyprus, particularly for the PGM and α-GPDH enzyme genes (each of which has an allele tending towards fixation) constitute an important tool for drawing conclusions regarding the insect’s dispersal pathways from its place of origin in Europe.
source: dspace.aua.gr