A two locus barcode for discriminating <em>Piper nigrum</em> from its related adulterant species

Abstract

DNA barcoding in plants involves the selection and sequencing of DNA regions as a tool for species identification. Here we have attempted to discriminate <em>Piper</em> <em>nigrum</em> L., black pepper of commerce, from its related adulterant species viz., <em>Piper</em><em> attenuatum </em>Buch-Ham, <em>Piper</em><em> galeatum</em> (Miq.) C. DC. using <em>rbcL</em>, <em>psbA-trnH</em>, <em>rpo'C'l</em>, and <em>matK </em>as barcode loci. No single barcoding locus could discriminate all the three species of <em>Piper</em>. However <em>rbcL</em> and <em>rpoC1</em> could differentiate <em>P. attenuatum</em> from <em>P. nigrum</em> and <em>Piper galeatum</em> while <em>psbA-trnH</em> differentiated <em>P. galeatum</em> from <em>P. nigrum </em>and <em>P. attenuatum</em>. Two locus barcode approach proved better when compared to single locus in discriminating <em>Piper</em> species. The coding <em>rbcL</em> gene with non coding <em>psbA-trnH</em> spacer was preferred than the coding <em>rpoC1 + psbA-trnH</em> combination in the present study.