Dataset: DNA barcodes and microsatellites: how they complement for species identification in the complex genus Tamarix (Tamaricaceae)

DNA barcoding allows the identification of an organism by comparing the
sequence of selected DNA regions (barcodes) with a previously compiled
database, and it can be useful for taxonomic identification of species in
complex genera, such as Tamarix. Many species of this genus show
convergent morphology, which leads to frequent errors in their
identification. Highly variable genetic markers, such as microsatellites
or short sequence repeats (SSR), could be used to differentiate species
where DNA barcodes fail. Here, we tested the ability of both, five
different marker regions (rbcL, matK, ITS, trnH-psbA, and ycf1), and 14
microsatellites, to properly identify Tamarix species, especially those
from the Mediterranean Basin, and compared the pros and cons of the
different analytical methods for species identification. DNA barcoding
allows the genetic identification of certain species in Tamarix. The
two-locus barcodes matK+ITS and ITS+ycf1 were the best-performing
combinations, allowing up to 69% and 70%, respectively, correct
identification. However, DNA barcoding failed in phylogenetically close
groups, such as many Mediterranean species. The use of SSR can aid the
identification of species, and the combination of both types of data (DNA
barcoding and SSR) improved the success. The combination of data was
especially relevant in detecting the presence of hybridization processes,
which are common in the genus. However, caution must be exercised when
choosing the clustering methods for the SSR data, since different methods
can lead to very different results.