title: FREQUENT CLONALITY IN FUCOIDS (FUCUS RADICANS AND FUCUS VESICULOSUS; FUCALES, PHAEOPHYCEAE) IN THE BALTIC SEA(1).
abstract: Asexual reproduction by cloning may affect the genetic structure of populations, their potential to evolve, and, among foundation species, contributions to ecosystem functions. Macroalgae of the genus Fucus are known to produce attached plants only by sexual recruitment. Recently, however, clones of attached plants recruited by asexual reproduction were observed in a few populations of Fucus radicans Bergström et L. Kautsky and F. vesiculosus L. inside the Baltic Sea. Herein we assess the distribution and prevalence of clonality in Baltic fucoids using nine polymorphic microsatellite loci and samples of F. radicans and F. vesiculosus from 13 Baltic sites. Clonality was more common in F. radicans than in F. vesiculosus, and in both species it tended to be most common in northern Baltic sites, although variation among close populations was sometimes extensive. Individual clonal lineages were mostly restricted to single or nearby locations, but one clonal lineage of F. radicans dominated five of 10 populations and was widely distributed over 550 × 100 km of coast. Populations dominated by a few clonal lineages were common in F. radicans, and these were less genetically variable than in other populations. As thalli recruited by cloning produced gametes, a possible explanation for this reduced genetic variation is that dominance of one or a few clonal lineages biases the gamete pool resulting in a decreased effective population size and thereby loss of genetic variation by genetic drift. Baltic fucoids are important habitat-forming species, and genetic structure and presence of clonality have implications for conservation strategies.
authors.affiliation: Department of Marine Ecology - Tjärnö, University of Gothenburg, SE-452 96 Strömstad, SwedenDepartment of Environmental and Marine Biology, Åbo Akademi University, FI-20520 Åbo, FinlandDepartment of Botany, Stockholm University, SE-106 91 Stockholm, SwedenDepartment of Marine Ecology - Tjärnö, University of Gothenburg, SE-452 96 Strömstad, Sweden.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Johannesson
authors.affiliation: Department of Marine Ecology - Tjärnö, University of Gothenburg, SE-452 96 Strömstad, SwedenDepartment of Environmental and Marine Biology, Åbo Akademi University, FI-20520 Åbo, FinlandDepartment of Botany, Stockholm University, SE-106 91 Stockholm, SwedenDepartment of Marine Ecology - Tjärnö, University of Gothenburg, SE-452 96 Strömstad, Sweden.
authors.forename: Daniel
authors.initials: D
authors.lastname: Johansson
authors.affiliation: Department of Marine Ecology - Tjärnö, University of Gothenburg, SE-452 96 Strömstad, SwedenDepartment of Environmental and Marine Biology, Åbo Akademi University, FI-20520 Åbo, FinlandDepartment of Botany, Stockholm University, SE-106 91 Stockholm, SwedenDepartment of Marine Ecology - Tjärnö, University of Gothenburg, SE-452 96 Strömstad, Sweden.
authors.forename: Karl H
authors.initials: KH
authors.lastname: Larsson
authors.affiliation: Department of Marine Ecology - Tjärnö, University of Gothenburg, SE-452 96 Strömstad, SwedenDepartment of Environmental and Marine Biology, Åbo Akademi University, FI-20520 Åbo, FinlandDepartment of Botany, Stockholm University, SE-106 91 Stockholm, SwedenDepartment of Marine Ecology - Tjärnö, University of Gothenburg, SE-452 96 Strömstad, Sweden.
authors.forename: Cecilia J
authors.initials: CJ
authors.lastname: Huenchuñir
authors.affiliation: Department of Marine Ecology - Tjärnö, University of Gothenburg, SE-452 96 Strömstad, SwedenDepartment of Environmental and Marine Biology, Åbo Akademi University, FI-20520 Åbo, FinlandDepartment of Botany, Stockholm University, SE-106 91 Stockholm, SwedenDepartment of Marine Ecology - Tjärnö, University of Gothenburg, SE-452 96 Strömstad, Sweden.
authors.forename: Jens
authors.initials: J
authors.lastname: Perus
authors.affiliation: Department of Marine Ecology - Tjärnö, University of Gothenburg, SE-452 96 Strömstad, SwedenDepartment of Environmental and Marine Biology, Åbo Akademi University, FI-20520 Åbo, FinlandDepartment of Botany, Stockholm University, SE-106 91 Stockholm, SwedenDepartment of Marine Ecology - Tjärnö, University of Gothenburg, SE-452 96 Strömstad, Sweden.
authors.forename: Helena
authors.initials: H
authors.lastname: Forslund
authors.affiliation: Department of Marine Ecology - Tjärnö, University of Gothenburg, SE-452 96 Strömstad, SwedenDepartment of Environmental and Marine Biology, Åbo Akademi University, FI-20520 Åbo, FinlandDepartment of Botany, Stockholm University, SE-106 91 Stockholm, SwedenDepartment of Marine Ecology - Tjärnö, University of Gothenburg, SE-452 96 Strömstad, Sweden.
authors.forename: Lena
authors.initials: L
authors.lastname: Kautsky
authors.affiliation: Department of Marine Ecology - Tjärnö, University of Gothenburg, SE-452 96 Strömstad, SwedenDepartment of Environmental and Marine Biology, Åbo Akademi University, FI-20520 Åbo, FinlandDepartment of Botany, Stockholm University, SE-106 91 Stockholm, SwedenDepartment of Marine Ecology - Tjärnö, University of Gothenburg, SE-452 96 Strömstad, Sweden.
authors.forename: Ricardo T
authors.initials: RT
authors.lastname: Pereyra
keywords: asexual reproduction; clonal richness; macroalgae; population genetic structure; salinity gradient