RESUMEN
<p><b>OBJECTIVE</b>This research focused on analyzing the differences of 5S rRNA gene spacer sequences on Swertia mussotii and its commonly used adulterants, including S. franchetiana, S. wolfangiana and S. chirayita.</p><p><b>METHOD</b>DNA was extracted from the collected Swertia samples. 5S rRNA intergenic spacers were amplified by PCR, sequenced and analyzed.</p><p><b>RESULT</b>5S rRNA gene spacer sequences were different between S. mussotii and its other three adulterants. Sequence divergence among species ranged from 30.6% to 65.0%.</p><p><b>CONCLUSION</b>5S rRNA spacers may be used as molecular authentication markers to differentiate S. mussotii and other commonly used Swertia adulterants. This result provides reliable and simple reference for the authentication of Swertia genus species.</p>