## 3 Results and Discussion  
The restriction profiles after the digestion with _Alu_I and _Hae_III enzymes are shown in Table 2. Identical profiles using the same enzymes were observed by [PERSON] et al. [12]. All individuals originating from Mousda stream (Falakro Mountain, Greece), as well as the majority of those from Arkoudorema-Dramal and from Vathyrema near Kalikarpo, had the same genotype with the prevalent one from Achelos populations (composite genotype BB), whereas in all trout samples from Diavolorema, Farasino, and Vathyrema near Elatia forest, the autochthonous haplotype (composite genotype AA) was observed (Table 3). No composite genotype AB or BA was observed. In the sequence analyses, the entire mitochondrial control region (1021 bp) was successfully aligned for 18 individuals and revealed 10 variable sites that defined four different haplotypes, all of which were recorded for the first time. The three out of four haplotypes (haplotypes A, B, C) were observed among the 38 individuals that had the AA composite genotype in RFLPs analyses (supposed autochthonous individuals). In haplotypes A and B the first 305 nucleotides in the side of tRNA proline were identical with haplotype E (GenBank accession number: U63790) described in [PERSON] et al. [5], which was found in Nestos trouts that were not affected by the stockings, while haplotype C was one mutational step distant from haplotype E. Similarly, the 305 nucleotides in the side of tRNA proline in haplotype D were identical with the haplotype \"G\" (GenBank accession number: U63792) in [PERSON] et al. [4] that was observed in trouts from Acheloos River. This haplotype was observed in a specimen from Vathyrema that had the BB genotype in RFLPs. Thus, sequencing results were in accordance with RFLP results. Brown trout populations of the southern Balkans are characterized by extensive genetic diversity [3; 12]. It is worth noting that out of the five distinct mtDNA phylogenetic lineages that have been revealed throughout _Salmo trutta_ range, four have been detected in the Balkan area [5]. The maximum likelihood dendrogram of Figure 2, depicting the phylogenetic relationships among the four haplotypes found in this study, revealed that haplotypes A, B, and C were clustered together and supported with high bootstrap values with haplotype ADcs1 (AY836330, [17]), which is presumed to be the ancestral haplotype in the Adriatic (Ad) major phylogenetic lineage [3], and thus belong to the Ad lineage. On the other hand, haplotype D was clustered in the same branch with haplotype MACs1 (AY836365, [17]), hence belongs to the _marmoratus_ lineage. These inferences are in accordance with previous mtDNA studies [5] that revealed that the trouts from Acheloos \begin{table}
\begin{tabular}{c c c c} \hline \hline  & _AluI_ & & _HaeIII_ \\ \hline A & B & A & B \\  & & 1090 & 870 & \\
940 & & 710 & 710 \\
490 & 490 & & 580 \\
280 & 280 & 570 & 570 \\
250 & 250 & & 290 \\
230 & 230 & 170 & 170 \\
150 & & 130 & 130 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Restriction profiles (in base pairs) after the digestion with _Alu_I and _Hae_III. Fragments with sizes smaller than 100 bp are not shown. \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Composite** & & & & & & & & & & \\
**Genotype** & **MOU** & **VATH1.1** & **VATH1.2** & **VATH1.3** & **VATH1.4** & **VATH2** & **ARK1** & **ARK2** & **DIAV** & **FAR** \\ \hline AA & & & & \(1/5\) & \(1/3\) & \(7/7\) & \(3/11\) & \(6/6\) & \(6/6\) & \(11/11\) \\ BB & 9/9 & 5/5 & \(3/3\) & \(4/5\) & \(2/3\) & & \(8/11\) & & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Haplotypes (composite genotypes) and haplotype frequencies of the examined samples as revealed by RFLPs. River mainly belong to the _marmoratus_ major phylogenetic mtDNA lineage, while the autochthonous trouts from Nestos River belong to the Adriatic lineage.