DNA extraction from processed wood:: A case study for the identification of an endangered timber species (Gonystylus bancanus)

We applied human forensic techniques to the extraction of whole genomic DNA from processed wood samples to explore the possibility of identifying an endangered tropical timber species by using DNA sequencing technology. High-yield and high-quality DNA samples were obtained from 2 commercial wood and 3 herbarium samples. Large PCR fragments ranging from 500-800 bp were successfully amplified from 2 chloroplast and I mitochondrial regions in all 5 samples, indicating limited degradation of the cytoplasmic genomes. DNA extraction from stem wood taken from herbarium specimens appeared superior to that from stem wood with bark intact or from leaf samples. DNA sequences from the trn regions allowed for easy identification of the focal species based on GenBank Blast search. Little sequence variation was observed in the 3 regions, with the mitochondrial cox3 region completely conserved. Extraction of high-quality and large intact DNA fragments makes dry wood materials amenable to various DNA marker-based applications, including fingerprinting and historical approaches. By sampling stemwood, the wealth of historical information housed in international herbaria can be explored with minimal damage to taxonomically important features.