De Clerck, O.

Steen Redecker, E.

Open Marine Archive

 - 81 -
PHYLOGEOGRAPHY AND POPULATION STRUCTURE OF THE BROWN 
SEAWEED DICTYOTA DICHOTOMA (DICTYOTALES, PHAEOPHYCEAE) 
ALONG EUROPEAN COASTLINES 
Steen Frédérique and Olivier De Clerck 
Phycology Research Group, Ghent University, Krijgslaan 281, S8, 9000 Gent, Belgium 
E-mail: Frederique.Steen@ugent.be  
The population structure of the common brown seaweed species Dictyota dichotoma along 
European shores was explored employing one newly developed mitochondrial marker. D. dichotoma 
belongs to a warm-temperate phytogeographic group with north-eastern extension. Its geographical 
distribution covers the northeast Atlantic, the Mediterranean and the Macaronesian archipelago with 
exclusion of Cape Verde. Analysis of a total of 281 individuals from 19 sampling locations revealed 
a reasonable level of polymorphism. A first exploration of the phylogeography of D. dichotoma is 
presented. Diversity was highest for the southern distribution area, but unexpectedly several private 
alleles were found in the northeast Atlantic. Analysis of molecular variance reveals that Atlanto-
Mediterranean populations are comparable but clearly distinct from Canary Islands populations. 
Mismatch distribution analysis on the Atlanto-Mediterranean samples did not reject the hypothesis 
of sudden expansion. Our data suggest a postglacial recolonization of the northeast Atlantic from a 
potential southern glacial refugium located near the Iberian Peninsula. Future research aims to 
analyze a multilocus dataset (including mitochondrial, chloroplast and nuclear markers) by model-
based phylogeography based on coalescent theory. 


Phylogeography and population structure of the brown seaweed <i>Dictyota dichotoma</i> (Dictyotales, Phaeophyceae) along European coastlines

Abstract

Similar works

Full text

Available Versions

Open Marine Archive