Book of Abstracts (PDF) - International Mycological Association

IMC7 Thursday August 15th Lectures
284 - Foliicolous lichens: Evolution and ecology of an
unusual growth habit
R. Lücking
Botany Department, The Field Museum, 1400 S Lake Shore
Drive, Chicago, IL 60605-2496, U.S.A. - E-mail:
rlucking@fieldmuseum.org
Foliicolous lichens inhabit leaves of vascular plants in
tropical rainforests. They have to adapt to the short
longevity of their substratum, as leaves are mostly shed
after 12 to 36 months. Furthermore, they must not interfere
with leaf functions of gas exchange and photosynthesis. In
spite of these limitations, foliicolous lichens evolved a
surprising diversity and unique phenotypic features. Fifty
species can be found on a small leaf, and 300 taxa within a
single rainforest spot. Following their needs for rapid
dispersal in a semi-aquatic environment, foliicolous lichens
developed particular, convergent dispersal strategies, such
as disc-shaped isidia (vegetative), derived conidiomata
(asexual), and facultative parasitism on other lichens
(sexual reproduction). Based on different evolutionary
models of foliicolous lichen growth, and using phenotypebased
phylogenetic analyses of selected groups, we tested
whether individual features fulfill the criteria of 'key
innovations' and led to subsequent radiation. It is concluded
that radiation occurred only when sexual and asexual
reproduction were maintained as principal dispersal modes
within a clade, and the nature of radiation, whether specific
or generic, depended on the inherent plasticity of the
putative 'key innovation'. Thus, clades characterized by
facultative parasitism or derived conidiomata show a high
degree of radiation, while speciation is virtually absent in
clades with specialized vegetative dispersal organs.
285 - The phylogeny of Roccella (Roccellaceae) with
emphasis on the Macaronesian species
Å. Dahlkild 1* , M. Källersjö 2 & A. Tehler 3
1
Botaniska Institutionen, Stockholms Universitet, 106 91
Stockholm, Sweden. - 2 Molekylärsystematiska laboratoriet,
Naturhistoriska Riksmuseet, Box 50007, 104 05 Stockholm,
Sweden. -
3 Sektionen för kryptogambotanik,
Naturhistoriska Riksmuseet, Box 50007, 104 05 Stockholm,
Sweden. - E-mail: Asa.Dahlkild@botan.su.se
This paper presents a phylogenetic analysis of the
lichenized fungal genus Roccella (Roccellaceae,
Arthoniales), focussing on the Macaronesian species. The
ITS rDNA region, including the 5.8S region, ITS1, and
ITS2, was sequenced for 14 Roccella species, including
two putative species pairs. The sequence information was
analyzed under a range of alignment parameters, and with
gaps coded as missing data. The genus Roccella is found
not to be monophyletic, since two species, Roccella
hypomeca and Roccella portentosa, are more closely
related to another genus, Roccellina. Dirina is the sister
group of the core Roccella, as found in earlier studies. The
Macaronesian species form a monophyletic group in some,
but not in all analyses. Our study also indicates that the two
putative species pairs Roccella allorgei/Roccella africana
and Roccella tinctoria/Roccella canariensis each should be
treated as conspecific.
286 - The Sphaerophorus globosus species complex -
morphology re-interpreted with molecular phylogeny
M. Wedin 1* & F. Högnabba 2
1 Dept. of Ecology and Environmental Science, Umeå
University, SE-901 87 Umeå, Sweden. - 2 Dept. of Ecology
and Systematics, University of Helsinki, P.O. Box 47, FIN-
00014 Helsinki, Finland. - E-mail: mats.wedin@eg.umu.se
The Sphaerophorus globosus species complex
(Lecanorales, lichenised Ascomycota) shows a surprisingly
large morphological variation, and several relatively
distinct morphotypes can be distinguished over the
distribution area. We have sampled populations from most
areas where the species complex occurs, with a particular
focus on the populations in the North American Pacific
Northwest, where the morphological variation is very large
in the group. In this study, we utilise a multi-gene based
maximum-parsimony approach (nITS+LSU rDNA, mtSSU
rDNA, ß-tubulin, actin) to investigate the phylogeny of this
complex. If the different morphotypes constitute distinct
monophyletic groups in the multi-gene phylogenies, this
would support the hypothesis that the morphotypes are
different phylogenetic species. Monophyletic groupings
corresponding to geographical origin would, on the other
hand, support the alternative hypothesis that the different
morphologies are likely to be caused by the
environmentally induced phenotypic variation, rather than
by common descent. The results point at the presence of
several distinct phylogenetic species in the group.
287 - Phylogeny of Ostropales and Gyalectales -
evidence from molecular and ontogenetical data
F. Kauff 1* , F. Lutzoni 2 & B. Büdel 1
1 University of Kaiserslautern, FB Biologie, Abt. Allg.
Botanik, Postfach 3049, 67653 Kaiserslautern, Germany. -
2 Duke University, Dept. of Botany, Box 90338, Durham,
NC 27708, U.S.A. - E-mail: kauff@rhrk.uni-kl.de
Despite various morphological and anatomical similarities,
the two orders Gyalectales (lichenized ascomycetes) and
Ostropales (lichenized and non-lichenized ascomycetes)
have been considered to be distantly related to each other,
and their position within the Ascomycota was unsettled. To
estimate relationships within these groups and their
respective phylogenenetic placement within the
Ascomycota, we investigated the ascoma ontegeny and
analyzed DNA sequences from the SSU and LSU nrDNA
using Max. Parsimony, Max. Likelihood, and Bayesian
statistics with Markov chain Monte Carlo algorithms. We
Book of Abstracts 91