DOI: 10.5061/dryad.ds2714g
title: Data from: Local coastal configuration rather than latitudinal gradient shape clonal diversity and genetic structure of Phymatolithon calcareum maerl beds in North European Atlantic

description: Maerl beds are one of the world’s key coastal ecosystems and are
 threatened by human activities and global change. In this study, the
 genetic diversity and structure of one of the major European maerl-forming
 species, Phymatolithon calcareum, was studied using eight microsatellite
 markers. Two sampling scales (global: North East Atlantic and regional:
 Galicia) were investigated and fifteen maerl beds from Atlantic Europe
 were sampled. At the regional-scale the location of sites outside and
 within four estuaries allowed to test for the influence of coastal
 configuration on population connectivity and genetic diversity. Results
 suggested that clonal reproduction plays an important role in the
 population dynamics of P. calcareum maerl beds. Clonality was variable
 among populations, even within the same region. At the European scale,
 these differences in clonality cannot be explained by the geographic or
 latitudinal distribution of the populations studied. A significant genetic
 differentiation was found among almost all population pairs and a positive
 correlation between geographic and genetic distances showed the limited
 dispersal capacity of P. calcareum. Moreover, a very clear pattern of
 genetic structure was revealed at the regional scale between populations
 located within and at the mouth of the estuaries. Genetic differentiation
 among estuaries was less marked for the sites located in outer-zones
 compared to those located in the inner-zones. In addition, variation in
 level of clonality linked to seascape was also observed: populations
 situated in the outer-zones of the estuaries were less clonal than those
 in the inner-zones. Finally, populations from the same estuary generally
 shared one or several mutilocus genotypes.
description: Microsatellite genotypes
 of Phymatolithon calcareum in the AtlanticGenotype profile of 455
 samples of the maerl bed forming red alga Phymatolithon calcareum
 collected at 14 study sites and scored for eight microsatellite markers
 (allele 000: missing data). Reproductive state of each sample was defined
 by direct observation under a binocular microscope and ploidy level by
 presence of specific reproductive organs and / or genotype characteristic
 (i.e., individuals with MLGs including at least one heterozygous locus
 considered as diploids; 2n: diploids; 3n: possible triploids). ID:
 identifier; MLG: distinct MultiLocus Genotypes detected in each site;
 Psex: probability that a given MLG derive from distinct sexual
 reproductive events as estimated in the GENECLONE v.2.0 software
 (Psex&lt;0.05 are given in bold). Accompanying publication : Pardo et al.
 Under review Frontiers in Marine Science “Population genetics of
 Phymatolithon calcareum maerl beds in North European Atlantic: influence
 of coastal configuration on connectivity and level of clonality”. Contact
 author regarding data analyses: Marie-Laure Guillemin,
 marielaure.guillemin@gmail.comPardo_2019_FrontiersMarineScience_Population_genetic_microsatellites_Phymatolithon_calcareum.xlsx