Message - 7th IAL Symposium

3A-O
Lichen: from genome to ecosystem in a changing world
(3A-O4) Submission ID: IAL0143-00002
MULTI-GENE PHYLOGENY DEFINES THE MONOPHYLY OF LOBARIA SECTION LOBARIA
Cornejo C. 1 , Scheidegger C. 1
1 Biodiversity and Conservation Biology, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
Lobaria (Schreb.) Hoffm. is a genus of about 80 species that is hypothesized to have originated in
Eastern Asia from where taxa speciated and spread to other continents . Although Eastern Asian Lobaria species
were comprehensively revised, our understanding of taxa delimitation remains incongruous. Traditionally,
two sections are distinguished: Lobaria and Ricasolia with fusiform or acicular spores, respectively. Besides
the thallus morphology and chemical compounds, the presence of apothecia and the morphology of vegetative
propagules were most determinant attributes for the definition of species. While some species were separated
based on combinations of several morphological and chemical characters, other taxa were described based on
one distinguishing feature alone. For instance, taxa that were identical, except for the presence of vegetative
diaspores, were recognized as distinct species-pairs. In our study, we focused primarily on the section Lobaria
and we tested the monophyly of this section. For this study, we performed phylogenetic analyses with a vast
sampling, mainly from Eastern Asia, and based on five genetic loci (nrITS, nrLSU, EF-1a, RPB2 and mrSSU).
Additionally to morphological studies, we analyzed lichen compounds with TLC and tested key criteria in relation
to the resulting phylogenetic framework. Our analyses clearly confirmed the monophyly of the section Lobaria
and of most species within this section, but relationships among taxa belonging to the section Ricasolia remained
inconsistent. Within the section Lobaria, however, different markers produced conflicting phylogenetic information
for some species. In addition, some Eastern Asian taxa showed low phylogenetic resolution, thus, only
concatenated analysis revealed clades, challenging however traditional systematics and the described species
abundance for this region. This, in combination with the fact that these species were not monophyletic, suggests
that lineage sorting is incomplete. This is the first phylogenetic hypothesis presented for the section Lobaria that
includes an extensive sampling, and the clades recovered contrast sharply with previously defined taxa based
on morphological and chemical characters. Our results demonstrate difficulties that may arise in the integration
of molecular data within traditional systematics.
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