title: Molecular authentication of the medicinal herb Ruta graveolens (Rutaceae)  and an adulterant   using nuclear and chloroplast DNA markers.
abstract: Dried parts of different plant species often look  alike, especially in powdered form, making them very difficult to identify. Ruta  graveolens, sold as a dried medicinal herb, can be adulterated with Euphorbia  dracunculoides. The genomic DNA was isolated from the leaf powder (100 mg  each) using the modified CTAB method. Internal transcribed spacer sequences of  nuclear ribosomal DNA (nrDNA-ITS), and chloroplast spacer sequences (rpoB and rpoC1) are regarded as potential genes for plant DNA barcoding. We  amplified and sequenced these spacer sequences and confirmed the sequences with  a BLAST search. Sequence alignment was performed using ClustalX to look for  differences in the sequences. A DNA marker was developed based on rpoB and rpoC1 of the nrDNA-ITS for the identification of the adulterant E.  dracunculoides in samples of R. graveolens that are sold in local  herbal markets. Sequence-characterized amplified region markers of 289 and 264  bp for R. graveolens and 424 bp for E. dracunculoides were  developed from dissimilar sequences of this nrDNA-ITS to speed up the  authentication process. This marker successfully distinguished these species in  extracted samples with as little as 5 ng DNA/μL extract.
authors.affiliation: Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Saudi Arabia.
authors.forename: F
authors.initials: F
authors.lastname: Al-Qurainy
authors.forename: S
authors.initials: S
authors.lastname: Khan
authors.forename: M
authors.initials: M
authors.lastname: Tarroum
authors.forename: F M
authors.initials: FM
authors.lastname: Al-Hemaid
authors.forename: M A
authors.initials: MA
authors.lastname: Ali
mesh_terms: D018742:DNA, Chloroplast / Q000235:genetics* / Q000302:isolation & purification; D004275:DNA, Ribosomal / Q000235:genetics* / Q000302:isolation & purification; D028481:Euphorbia / Q000235:genetics; D005819:Genetic Markers; D016133:Polymerase Chain Reaction; D032105:Ruta / Q000235:genetics*; D016415:Sequence Alignment / Q000379:methods; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D018742:DNA, Chloroplast; D004275:DNA, Ribosomal; D005819:Genetic Markers