A preliminary study of genetic diversity in Cystoseira amentacea (C. Agardh) Bory var. stricta Montagne (Fucales, Phaeophyceae) using random amplified polymorphic DNA

Abstract

M.-L. Susini, T. Thibaut, A. Meinesz and D. Forcioli. 2007. A preliminary study of genetic diversity in Cystoseira amentacea (C. Agardh) Bory var. stricta Montagne (Fucales, Phaeophyceae) using random amplified polymorphic DNA. Phycologia 46: 605–611. DOI: 10.2216/06-100.1

Cystoseira amentacea var. stricta is an endemic key species in the coastal ecosystem of the northern Mediterranean basin. Because it has suffered significant population declines, it has been designated a protected species. Nothing is known about the population genetics of Cystoseira spp. Because zygote dispersal is low among the Fucales, low genetic diversity within populations and strong differentiation among populations were predicted. To evaluate genetic variation within and among C. amentacea var. stricta populations, 54 individuals from four populations were compared using random amplified polymorphic DNA (RAPD) markers. Data were analyzed using analysis of molecular variance (AMOVA) and Bayesian clustering of individuals into populations based on their genotypes (STRUCTURE 2.1 software). Results indicated that genetic variation is high, with most of it distributed within populations (70.93%), and with some genetic mixing among adjacent populations, a result of longer range dispersal. The Lavezzi population (Corsica) is distinct from the other three populations, suggesting isolation by distance. Although more intensive sampling is required, these preliminary results have important implications for conservation policy.

Key Words::

• Cystoseira amentacea var. stricta
• RAPD markers
• Genetic diversity
• Mediterranean Sea

ACKNOWLEDGMENTS

We thank the two anonymous reviewers and Dr M. Poirié for their helpful comments on this manuscript. This work was supported by a grant from the Région Provence-Alpes-Côte-d'Azur.