We are happy
to share the first results of our genetic characterization of seagrass communities
in Cabrera. To date, no metabarcoding protocol had been applied to this kind of
communities, so we devised one of our own.
We studied two
different seagrass meadows (Posidonia
oceanica) in Cabrera. One was located in Cala Santa Maria and was more
sheltered, while the one in L’Olló was more exposed to waves and storms. We took
replicate samples using corers 20 cm in diameter. We then separated the leaves
from the rizhome fraction. Leaves and ryzhomes were “shaved” with razor blades,
and the material obtained homogenized with a blender.
We
extracted DNA from the resulting fractions using the Qiagen Power Max Soil kit,
and amplified a fragment of the COI mitochondrial genes (Leray fragment) using
universal primers. After a bioinformatic pipeline, we ended up with 5,333 eukaryote
MOTUS (Molecular Operational Taxonomic Units, our proxy for species).
We are now
analysing these data, but just some preliminary analysis, such as the MDS (MultiDimensional
Scaling) below, shows that the communities in leaves and rhizomes are
different, and there were also differences between the two seagrass meadows.
The Posidonia oceanica samples were also
clearly set apart from other communities on hard substratum in Cabrera.
We are enthralled
with this new tool to analyse biodiversity in a community so far untapped with
genetic techniques.
