A Three-Locus, PCR-based Method for Forensic Identification of Plant Material*
Plant residue is currently an underutilized resource in forensic investigations despite the fact that many crime scenes, as well as suspects and victims, harbor plant-derived residue that could be recovered and analyzed. Notwithstanding the considerable skill of forensic botanists, current methods of species determination could benefit from tools for DNA-based species identification. However, DNA barcoding in plants has been hampered by sequence complications in the plant genome. Following a database search for usable barcodes, broad-spectrum primers were designed and utilized to amplify and sequence the rbcL, trnL-F, and rrn18 genetic loci from a variety of household plants. Once obtained, these DNA sequences were used to design species-targeted primers that could successfully discriminate the source of plant residue from among the 21 species tested.