Chloroplast DNA sequence data provides new insights into genetic diversity and phylogenetic relationships of Tunisian apricot germplasm

• Chloroplastic DNA polymorphism among Tunisian apricot germplasm.
• trnH–trnK intergenic spacer sequencing.
• Genetic diversity assessed with haplotypic and nucleotide diversity tests.
• Absence of phylogeographic structure.
• Existence of a common ancestor.

The single chloroplast DNA (cpDNA) trnH–trnK intergenic spacer was amplified using universal primers and sequenced for 40 apricot (Prunus armeniaca L.) accessions collected throughout different growing areas in Tunisia. Significant genetic diversity was revealed at nucleotide sequences and in both haplotypic and nucleotide diversity tests. Data analysis revealed that each accession represented one haplotype except for the accessions ‘Bouk Hmed Akhal 32B’ and ‘Bargoug 40J’ which are grouped in the same haplotype. Thus, 39 different haplotypes were proved. The accession ‘Bargoug 40D’ originating from Gafsa, was located at the center of the haplotype network, which implied its ancient origin. No phylogeographic structure was demonstrated in apricot in Tunisia. In addition, results supported that a sudden demographic expansion model occurred in apricot species in Tunisia. These results provide some clues as the origin of apricot species in Tunisia as well as useful information for the management of apricot genetic resources.

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