Integrated analysis for identifying Portulaca oleracea and its sub-species based on chloroplastic and nuclear DNA barcoding

The taxonomy of Portulaca oleracea has been considered as being complex since the aggregate is composed of many subspecies or a group of micro-species based on seed-coat characters, seed size, and chromosome number. In order to enlarge the background of the extent of genetic variability between and within Tunisian P. oleracea accessions, a combined morphological and molecular approach was adapted, in the present survey. The morphological analyses of the spontaneous Tunis population display high intra population variability characterized by two distinct morphotypes corresponding to the botanical forms (wild and cultivated plant). Furthermore, the molecular approach based on sequences data related to chloroplastic and ribosomal DNA, was used to understand this variability. The obtained results highlighted the greater molecular variability of this plant and allowed to segregate between morphotypes and genotypes of Portulaca. Mostly, this work shows the important contribution of DNA barcoding approach in resolving low-level-taxonomy problems to distinguish between natural populations and varieties.