Raphaëlle Rinaldo

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PhD defended June, 12th 2012

University of French West Indies and French Guiana

Abstract

In order to develop a sustainable production of certified essential oils extracts, the company KLR has struggled with the identification of the trees from the family of Lauraceae. This is the main reason that led to the project of creating an identification tool for this family.

This tool is based on three approaches: chemistry (chemical signature of the bark), wood anatomy and genetic barcoding. By means of a non-metric multidimensional scaling analysis, we selected a list of 14 relevant wood anatomical features that can identify the trees to the genera. For the genetics, the barcoding of trnH-psbA an intergenic region of the DNA has been used. When comparing all the sequences from all the individuals, 40% of the individuals can be identified to the genera because of their specific haplotype. Haplotypes within the genera have also been established. Chemical identity cards have been set with the SPME analysis technique and chemotypes have been defined inside the species Licaria cannella, Ocotea indirectinervia and Sextonia rubra. These three identification approaches allowed us to construct an identification tool on Xper2.

During the study, we aimed to screen what species would be interesting for its essential oil yield. Three species showed an essential oil bark yield above 0.3%. Five species showed an essential oil wood yield above 0.3%. An expert held an olfactory evaluation on the oils and divided the essential oils in five olfactory groups. We found it relevant to improve the identification tool by trying to predict the compositions of the oils before the tree was cut down. In the case of the half of trees studied by SPME analyses, the composition of the wood and the bark essential oils were similar. On the other hand, no link was found between the oil cells dimensions and the essential oil yield.

Keywords: identification, oil production, Lauraceae, wood anatomy, barcoding, SPME, essential oils, French Guiana

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