Genetic Barcoding

How do we proceed?

First, we invest quite some effort into the authenticity of our reference plants that cultivated in the Botanical Garden and are verified by classical taxonomical determination. The quality of a method stands or falls with the authenticity of the reference plant. Therefore, all our plants carry an ID that never changes, even when the name of the plant changes (which is not a rare event - first, plant taxonomy is continuously reformed, such that names can change, second, an estimated 10-20% of entries in Botanical Gardens or gene banks are wrongly determined or named, such that often the plants, we get from other gardens, turn out to be something else after our identification). In the second step, databases are screened for presence of suitable genetic barcodes - the more markers are available, the informative they are, the better for the security of our results. We then isolate genomic DNA from the references and amplify the respective barcoding marker by PCR to obtain the sequence for later analysis. In parallel, the accessions are microscopically compared - interesting diagnostic markers are, for instance, stomatal patterns, the relation between pavement cells and palisade parenchyma, but also hairs, trichomes, or crystals. When the sequences arrive, they are aligned with sequences from the data base and used to construct a molecular phylogeny (neighbor-joining). Suitable sequence differences are then used as base to develop a diagnostic test - for instance, by RFLP or ARMS. 

 

Examples

  1. Project Bamboo as Novel Food. more...
  2. Project Deathly Bear Leek. more...
  3. Project TCM-Goji Berry. more...
  4. Project TCM-Allium fistulosum. more...

 

Publications

90. Horn T, Barth A, Rühle M, Häser A, Jürges G, Nick P (2012) Molecular Diagnostics of Lemon Myrtle (Backhousia citriodora versus Leptospermum citratum). Eur Food Res Technol 234, 853-861 - pdf

102. Horn T, Völker J, Rühle M, Häser A, Jürges G, Nick P (2014) Genetic authentication by RFLP versus ARMS? The case of Moldavian Dragonhead (Dracocephalum moldavica L.). Eur Food Sci Technol 238, 93-104 - pdf