DNA barcoding for Arecaceae and Fabaceae species identification of two plant collections

DNA barcoding is a well-known technique that enable species identification by using universal DNA sequences from a small fragment of the genome. In this work, the effectiveness of DNA barcoding approach was evaluated in order to identify different taxonomic groups among two families (Arecaceae and Fabaceae) from two flowering plant collections: some were economically important taxa from nursery production and Mediterranean plants with ornamental attitude for possible new introduction. Three chloroplast DNA barcode regions (matK, rbcL and trnH-psbA) proposed by the Consortium for the Barcode of Life (CBOL) were tested in 22 Arecaceae species and in eight Fabaceae species, including Ceratonia siliqua. The greatest success of discrimination was found in the Fabaceae in which all eight taxa were unambiguously identified, while in the Arecaceae, only seven out of 22 taxa were discriminated at the species level. The matK marker gave the lowest values of genetic divergence (GD) for the Arecaceae (1.5%) and the highest for Fabaceae (GD=6.4%); the rbcL marker was not particularly informative in the Arecaceae (GD=0.7%), as well as the TrnH-psbA (GD=2.9%). TrnH-psbA presented high variability values in the Fabaceae (GD=7.4%), while rbcL marker showed modest differences (GD=1.5%). Although additional markers or different primer combinations are needed for a better discrimination of the Arecaceae, our results confirmed the potential of the barcoding approach for quick identification of Mediterranean plant species. Data of taxa discriminated at the species level with the DNA barcoding methodology will be included in the database and can be used for traceability purpose to protect both the biodiversity and the economic interest of companies and end-users.