Forensic botany: species identification of botanical trace evidence using a multigene barcoding approach

Abstract

Forensic botany can provide significant supporting evidence during criminal investigations. However, it is still an underutilized field of investigation with its most common application limited to identifying specific as well as suspected illegal plants. The ubiquitous presence of plant species can be useful in forensics, but the absence of an accurate identification system remains the major obstacle to the present inability to routinely and correctly identify trace botanical evidence. Many plant materials cannot be identified and differentiated to the species level by traditional morphological characteristics when botanical specimens are degraded and lack physical features. By taking advantage of a universal barcode system, DNA sequencing, and other biomolecular techniques used routinely in forensic investigations, two chloroplast DNA regions were evaluated for their use as "barcoding" markers for plant identification in the field of forensics. We therefore investigated the forensic use of two non-coding plastid regions, psbA-trnH and trnL-trnF, to create a multimarker system for species identification that could be useful throughout the plant kingdom. The sequences from 63 plants belonging to our local flora were submitted and registered on the GenBank database. Sequence comparison to set up the level of identification (species, genus, or family) through Blast algorithms allowed us to assess the suitability of this method. The results confirmed the effectiveness of our botanic universal multimarker assay in forensic investigations.

Barcoding the major Mediterranean leguminous crops by combining universal chloroplast and nuclear DNA sequence targets

“…The sequences used, known as DNA barcodes, are usually short (300-800 bp) (Kress et al, 2005). Although chloroplast DNA barcoding is mainly used to identify plant species, its application could be extended to the food industry, evolution studies, and forensics (Ferri et al, 2009). Various regions of the plastid genome have been proposed to serve as DNA barcodes, including the rbcL, matK, rpoB, and C genes, the non-coding spacers atpF-atpH, trnH-psbA and psbK-psbI trnL-F, the trnL (UAA) intron, and the internal transcribed spacer (ITS) 2 region of nuclear ribosomes.…”

Evaluation of pyrosequencing for large-scale identificationof plant species (grasses as a model)

“…Should the SNP markers developed here prove to be species-specific, they would provide a valuable tool for reliable diagnosis of grasses. Such grassspecific markers can provide significant evidence during criminal investigations (Ferri et al, 2009) since very short DNA fragments, like those that remain in degraded DNA samples, were targeted in this study. They can also be useful for studies on the detection of chloroplast capture, which is usually caused by several crosses between 2 different species, by determining the mode of the cpDNA inheritance (Gulsen et al, 2005), the maternal parent of the hybrid and polyploid species (Mason-Gamer, 2004), and maintenance of germplasm collections.…”

A segment of rbcL gene as a potential tool for forensic discrimination of Cannabis sativa seized at Rio de Janeiro, Brazil

“…This makes the region well preserved, facilitating the design of universal primers used in molecular techniques [6,7]. Therefore, it can distinguish among species in the Order Rosales and/or the Cannabaceae family, allowing correct detection of species [8]. One example is the region of rbcL-orf106, containing a segment of approximately 3 kb, used in the work published by Gilmore et al [9] This study aims to test the performance of smaller segment of the rbcL gene as a potential tool to obtain a genetic signature of C. sativa in samples collected at the city of Rio de Janeiro, Brazil, and for discrimination among different known species of the Cannabaceae family, suggesting possible trafficking routes.…”