Adil GÜNER, Vehbi ESER - optima

Oral Lectures
32
POLLINATION ECOLOGY PROVIDES SOME NEW INSIGHT
INTO EVOLUTION AND SYSTEMATICS OF MEDITERRANEAN
LEGUMES
Giovanni CRISTOFOLINI, Marta GALLONI, Licia PODDA, Daniele VIVARELLI
Herbarium and Botanical Garden, University of Bologna, Italy. giovann.cristofolini@unibo.it
A great diversity of Leguminosae–Faboideae is found in the Mediterranean region, including
many endemic and rare taxa. Among tribes having their main diversity centre in the
Mediterranean area, let’s mention Loteae, Coronilleae, Vicieae, Cytiseae, the last being the
richest in species. It is well known that tribes and genera have been historically established on
morphological grounds, with special regard to floral characters. Recent taxonomic revisions,
mainly based upon molecular characters, have challenged the traditional taxonomic treatment, as
several genera that used to be regarded as natural ones, turned out to be polyphyletic. The
inconsistency between "traditional" (morphological) taxonomy and phylogenetic (molecular)
relationships is a major point of concern in pursuing a natural system of classification. The
question arises, whether the incongruence between natural groups based on morphological traits
and monophyla based on molecular homology is due to experimental flaws or has a biological
foundation. Pollinators’ ethology, form and size play a relevant role in shaping floral structures,
and more so when pollination is specialized. Most Legumes have been reported in the past to be
"generalist", i.e. pollinated by several different insect taxa. However, the very concept of
generalist vs. specialist species needs to be critically examined: a species pollinated by several
insect taxa may be specialized, as far as its fitness is enhanced by only one or few of them, or by
a structurally homogeneous insect guild, when other pollinators exert little influence on seed
production, or even depress it. In this light, recent evidence has shown that pollination in
Mediterranean Legumes may be much more specialized than previously reported. Such "cryptic"
specialization may account for homoplasy of floral characteristics, so the species that share
important floral features, and hence are regarded as forming "natural" genera, may be the
outcome of common pollination strategy rather than represent monophyletic clades.
Keywords: Faboideae, homoplasy, phylogeny, pollination specialization, taxonomy.
20