Chloroplast DNA Diversity of Oak Species in Eastern Romania

The chloroplast DNA of 34 sessile oak (Quercus petraea) and 27 pedunculate oak (Q. robur) populations covering the entire natural distribution of the two oak species in Eastern Romania was investigated using four large regions of the chloroplast genome by PCR and RFLP technique. A total of seven chloroplast DNA haplotypes sensu lato have been observed by analysing 305 mature trees. However, due to the high resolution of the electrophoresis method a total of 22 chloroplast variants could have been detected, with new mutations and fragment combinations in two of the amplified regions: psbC/trnD and trnT/trnF. All of the haplotypes belong to the phylogenetic lineages A and E, which originate from the Balkan Peninsula. Most of genetic diversity is distributed among populations (GST=0.779). The chloroplast DNA haplotypes are shared by the two oak species. Different dispersal abilities may explain the higher value of genetic differentiation among populations in sessile oak than in pedunculate oak.