Abstract
Recently, molecular genetics tools have become important in classification for the purpose of identifying and classifying living organisms. Among them, it is now very common to use short sequences of DNA in mitochondria or chloroplast, especially in plants, that generally known as DNA barcoding. In the present research, a fragment of 524 base pair of the core chloroplast plant DNA barcode (rbcL) gene was amplified and sequenced for 30 varieties of Rosa x damascena trigintipetala growing in Taif governorate at Saudi Arabia. The obtained data were aligned with their close species that already found in the Genbank database and were analyzed by neighbor-joining and maximum-likelihood methods and a single rooted tree was performed. The all Rosa x damascena trigintipetala varieties were clustered in one clade with Rosa persica and Rosa roxburghii. The genetic distance and tree topology specified that the Taif Roses varieties could be originated from Rosa persica and Rosa roxburghii.