NCJ Number
229263
Journal
Journal of Forensic Sciences Volume: 54 Issue: 6 Dated: November 2009 Pages: 1254-1260
Date Published
November 2009
Length
7 pages
Annotation
This paper reports on the design of a DNA-based molecular identification system for 100 Australian grasses that consisted of a series of polymerase chain reaction assays that enabled the progressive identification of grasses to different taxonomic levels.
Abstract
The study demonstrated "proof of concept" of a molecular identification system for trace botanical samples. The assessment suggests that the adoption of a system that combines this approach with DNA sequencing could assist the morphological identification of grasses found as forensic evidence. Grasses were used as the model species in this study because they are among the plant species most likely to be encountered as forensic trace evidence. Grasses have considerable potential as contact DNA evidence and could provide links between crime scenes and individuals, because they are plentiful in both urban and rural environments that are frequently used by people, as well as the grass spikelet's morphological adaptations for seed dispersal. The identification system developed for the 100 Australian grasses was based on DNA sequence variation in 4 chloroplast and 2 mitochondrial loci. Seventeen informative indel and 68 single-nucleotide polymorphisms were used as molecular markers for subfamily identification. The system's accuracy was confirmed by blind tests. The description of methods addresses the study system; sampling; DNA extraction, PCR, and DNA sequencing; location of variation; and primer design and optimization of taxon-specific molecular markers. 1 table, 2 figures, and 54 references