Bulletin of the National Research Centre (May 2019)
Development of DNA-based species identification and barcoding of three important timbers
Abstract
Abstract Background Wood identification is extremely important in the modern forest industry. Teak (Tectona grandis L. family verbanaceae), Black Rosewood (Dalbergia latifolia L. family Fabaceae), and Ben Teak (Lagerstroemia lanceolata L. family Lytheraceae) are significant economic timber species in tropical countries. T. grandis is one of the most expensive hardwoods. It occurs naturally in India, Myanmar, Thailand, Java, and Laos in South Asia. L. lanceolata a strong associate of T. grandis occurs in deciduous forest-adjoining states of Karnataka such as Andhra Pradesh and Telangana state in India. D. latifolia distributed in India, Indonesia, Myanmar, Nepal, Philippines, Sri Lanka, and Vietnam. The selected valuable timbers threatened illegal logging and deforestation. It is challenging for non-taxonomist to accurately recognize and identify the timber species based on the conventional methods. DNA barcoding technologies and large-scale screening of DNA variation in trees can be done routinely and much faster with higher taxonomic resolution than morphological determination methods. In this study, we selected two plastid-specific ribulose bisphosphate carboxylase (rbcL), maturase K (matK), and one nuclear-specific trnH-ITS (intergenic spacer region)-conserved barcoding marker to compare species inter- and intradetailed discrimination. The aim of this study was to develop an accurate species and their provenance identification to support conservation efforts of three selected species viz T. grandis, D. latifolia, and L. lanceolata in Karnataka, India. Results Among the three selected markers, only two markers (rbcL and trnH-ITS) were having potential to amplify and discriminate the intra- and interspecific regions of selected timbers and would have been used to get barcodes for each species. Additionally, rbcL (90–96%) has a higher discrimination dominance over trnH-ITS (80–86%). From the barcoding results, it was found that the T. grandis and D. latifolia samples that belong to the Institute of Wood Science and Technology Bangalore are genetically more related to Dharwad than Hassan region in Karnataka. Conclusion The present study provided a database in which DNA sequences from unknown samples could be matched as well as required sequences from which other timbers or plant species could be identified. The use of inbuilt unique properties of DNA database within a timber would serve as an important molecular element in forensic forestry to support the determination of identifying the species and their adulterants.
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