Genetic diversity in Tunisian rosy garlic populations (Allium roseum L.) as evidenced by chloroplastic DNA analysis: Sequence variation of non-coding region and intergenic spacers

Allium roseum (Alliaceae) is an important medicinal and aromatic plant in the flora of Tunisia. It is widespread in southern Tunisia, where it is commonly used as a therapeutic agent. However, its existence is seriously threatened because of over-collection.In the present study, we examined patterns of chloroplast DNA (cpDNA) variations in 24 populations. The sample included 75 individuals, in which three cpDNA fragments were sequenced (rpL32–trnL and rps4–trnT intergenic spacers and non-coding region psbM–trnDGUC). We found nine haplotypes based on seven polymorphic sites and one insertion/deletion, which showed low haplotype and nucleotide diversity (Hd = 0.316; π = 0.00016). The ancestral haplotype (cpA) was found to be widely distributed. Neither phylogeographical structures of haplotypes nor isolation by distance were present.