As currently delimited, the Brassicaceae comprise 61 tribes, 363 accepted genera, and 4148 species. Of these, only few genera
and species remain to be assigned to tribes. These figures differ substantially from those estimated a decade ago, in which 49 tribes,
321 genera, and 3660 species were recognized, of which 20 genera and 34 species were lacking tribal assignment (Al-Shehbaz, 2012).
BrassiBase's phylogenetic visualizations on tribal level are based on a ”synoptic diagram” of phylogenetic relationships“
redrawn from Hendriks et al. (2023) and which is based on a large gene capture experiment aiming to resolve genus-level
relationships.
BrassiBase provides the opportunity to run your own “ITS barcode sequence” (internal transcribed spacers 1 and 2 of
nuclear ribosomal DNA, including the 5.8 S gene) as query against the curated BrassiBase ITS blast library,
which holds 12,145 ITS sequences from all 61 tribes, 359 genera and 2578 species.
The ITS region of about 650 bp is easily accessible via simple PCR and using highly conserved primers. Even if the
quantity and quality of the isolated DNA are critical (a very small amount of leaf material, herbarium material,
single seeds, etc.), this molecular marker works sufficiently in most cases. If needed, the region can also be amplified
as separate fragments (ITS1 and ITS2) to be subjected to further DNA sequencing. In addition, the PCR product can be easily
cloned prior to sequencing.
Along with the blast search results a putative phylogenetic position will be indicated based on ML analysis.
However, the presented results cannot replace any detailed phylogenetic analysis! This tool is intended only to provide
reference points for subsequent own analyses. It should be kept in mind that the presented trees are based on ITS sequences
only, and they are also not constraint in their topology by evidence given from other phylogenetic studies. For the pros
and cons of ITS sequences as marker in phylogenetic studies please refer to Kiefer et al. (2014).
- Al-Shehbaz IA. 2012. A generic and tribal synopsis of the Brassicaceae (Cruciferae). Taxon 61: 931-954.
- Hendriks KP, Kiefer C, Al-Shehbaz IA, et al. 2023. Global Brassicaceae phylogeny based on filtering of 1,000-gene dataset. Current Biology 33: 1-17.
- Kiefer M, Schmickl R, German D, Lysak M, Al-Shehbaz IA, Franzke A, Mummenhoff K, Stamatakis A, Koch MA. 2014. BrassiBase: Introduction to a Novel Knowledge Database on Brassicaceae Evolution. Plant Cell and Physiology 55: e3
