Phylogenetic analyses of some Egyptian genus of Lamiaceae family using rbcL sequences

Abstract

Six local Egyptian commercial cultivars of family Lamiaceae, two cultivars of genus Ocimum L. (Basil), two cultivars of genus Menthe L. (Mint), and two cultivars of genus Thymus L. (Thyme) were analyzed for ribulose 1,5-bisphosphate carboxylase Large (rbcL) gene at the level of DNA sequences. All samples successfully amplified the ± 630 bp fragment. Additionally, the results of alignment analysis using BLASTN tools divulged that the sequence of DNA rbcL for the two local basil cultivars (Basil1 & Basil2) has similarities with (Ocimum basilicum, Ocimum tenuiflorum, Ocimum kilimandscharicum and Ocimum gratissimum) 100, 99.69, 99.37 and 99.06 respectively. In addition, two local mint cultivars (Mint 1 and Mint 2) has similarities with Mentha spicata, Mentha_pulegium, Mentha canadensis and Mentha menthaefolia, 99.85, 99.84, 99.69 and 99.53 respectively. For thyme local cultivars (Thyme1 and Thyme2), Thym1 cultivar sample genotype is genetic closely with species, (Thymus alsinoides and Thymus sibthorpii) with 99.69 and 99.84 respectively and they located nearest from the cluster (Thymus genus) members in phylogenetic trees while, Thym2 is located after the cluster with Artemisia genus belonging to family Asteraceae. The reason of this result may be occurring due to that a Thym2 genotype comes from local marketing, which some of them are selling it as a thymus genus however, it is belongs to Artemisia genus and has similarities with with seven species of Artemisia genus (Artemisia absinthium, Artemisia gmelinii, Artemisia selengensis, Artemisia scoparia, Artemisia maritima, Artemisia capillaris and Artemisia fukudo). Using of rbcL DNA barcode proves to be effective in identifying the plants from the family level up to the genus level. This study demonstrates the efficiency of using rbcL barcoding primer to classify family Lamiaceae phylogenetically. It is also concluded that the rbcL gene showed genuine potentials to distinguish the plant Egypt species under investigation into the proper family and genus.