Characterization of population genetic structure of Cystoseira amentacea var. stricta (Phaeophyceae) in the Mediterranean Sea

• Published in: Phycologia (Oxford) Vol. 48; no. 4
• Main Authors: Bottin, L, Robvieux, P, Videment, J, Susini, M L, Thibaut, T
• Format: Journal Article
• Language: English
• Published: 01.07.2009
• Subjects: Cystoseira; Fucales; Phaeophyceae; MED
• ISSN: 0031-8884

Cystoseira algal communities (Fucales, Phaeophyceae) are considered as the final stage (climax) in a succession of photophilous algal communities, and are therefore a good indicator of the "ecological quality" of the coastal ecosystem. These communities play an important role in the structuration of the biodiversity on rocky substrates. Cystoseira amentacea var. stricta is endemic to the Mediterranean Sea and is located in the eulittoral zone. It is found mainly in exposed sites so the populations along the coast are fragmented. Moreover, the reproductive characteristics of this species makes long-distance dispersal difficult. Hence, the gene flow between populations is expected to be low. Recent studies report a regression of the populations, probably due to anthropogenic disturbances. To assess the connectivity between the populations and their potentiality to be maintained in the long term, we studied the genetic structure of the populations, and the gene flow between them. These issues are addressed using genetic markers: nuclear microsatellites. For the moment, 5 micro satellite loci have been identified and tested for 10 individuals in 6 populations. This study revealed low levels of heterozygosity suggesting the occurence of consanguinity in the populations. Moreover, the differentiation between populations was lower than expected. The validation of more microsatellites markers and their test for more individuals is expected in the next months and will enable to draw more accurate conclusions.