Tracing the Geographic Origin of Merbau (Intsia palembanica Miq.) in Century Old Planting Trials

Abstract

Our study highlights the utilization of a genetic database for wood-origin identification in Intsia palembanica, a valuable heavy hardwood from the tropical forests. This forensic tool is essential for strengthening the verification of legality in the wood supply chain from the forest to the end-users. An increasing number of rules and regulations are being put in place to promote sustainable practice in the timber trade, one of which involves ensuring that importers declare the correct species name and source of geographic origin of the timber. We aimed to determine the origin of the I. palembanica seed source used in the early establishment on the Forest Research Institute Malaysia (FRIM) campus. DNA samples of I. palembanica individuals from the FRIM campus were obtained and analyzed using four chloroplast (cp) DNA markers to characterize the haplotype variants for population identification. In addition, the DNA samples were also genotyped at 14 short tandem repeat (STR) loci for individual identification. Individual assignment to the possible geographic origin was done through an assignment test. On the basis of our recently developed I. palembanica genetic databases, the I. palembanica seed source for the early establishment was inferred to be originated from a mixture of several sources, with a large portion from the southern region (89%) and a relatively small portion from the northern region (11%) of Peninsular Malaysia. The I. palembanica seed source used for the early establishment on the century old FRIM campus was inferred to be originated from several forest reserves located not far from the planting sites. This study proves the applicability of the DNA method in supply-chain verification, where an unknown I. palembanica tree can be traced to its geographic origin using genetic databases.