Unterscheidung von zwei Thymianlieferungen für die Verwendung als Gewürz mittels molekularer Markeranalyse

The identity of a thyme delivery, imported for use in spice mixtures, was doubtful, since smell and consistency did not coincide with the characteristics of former supplies. Therefore, there was the assumption that plant material of a wrong genotype or species had been delivered. With conventional methods (microscopy) the identity of the species could not be clearly determined, an alternative molecular method should be developed. After extraction of the genomic DNA Internal Transcribed Spacer (ITS) sequences were amplified by PCR, sequenced, aligned with known sequences from Genbank and finally a phylogenetic tree was inferred by the Neighbor Joining method. It was clearly demonstrated that Thymus saturejoides was delivered from Egypt instead of Thymus vulgaris whereas the identity of the material from Morocco was clearly analyzed as Thymus vulgaris. With relatively little effort, the critical thyme sample could be unambiguously determined and classified. This method is also applicable to other aromatic plants.