Johannesson Kerstin, Johansson Daniel, Larsson Karl H, Huenchuñir Cecilia J, Perus Jens, Forslund Helena, Kautsky Lena, Pereyra Ricardo T
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.
J Phycol. 2011 Oct;47(5):990-8. doi: 10.1111/j.1529-8817.2011.01032.x. Epub 2011 Aug 19.
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.
通过克隆进行的无性繁殖可能会影响种群的遗传结构、进化潜力，以及作为基础物种对生态系统功能的贡献。已知墨角藻属的大型海藻仅通过有性繁殖来产生附着植物。然而，最近在波罗的海内部的一些鹿角墨角藻和囊链藻种群中，观察到了通过无性繁殖招募的附着植物克隆体。在此，我们使用9个多态性微卫星位点以及来自波罗的海13个地点的鹿角墨角藻和囊链藻样本，评估波罗的海墨角藻科植物中克隆性的分布和流行情况。克隆性在鹿角墨角藻中比在囊链藻中更为常见，并且在这两个物种中，克隆性在波罗的海北部地区往往最为普遍，尽管相近种群之间的差异有时很大。单个克隆谱系大多局限于单个或附近的地点，但鹿角墨角藻的一个克隆谱系在10个种群中的5个中占主导地位，并广泛分布在550×100千米的海岸线上。由少数克隆谱系主导的种群在鹿角墨角藻中很常见，并且这些种群的遗传变异性比其他种群要小。由于通过克隆招募的叶状体产生了配子，这种遗传变异减少的一个可能解释是，一个或少数克隆谱系的主导作用使配子库产生偏差，导致有效种群大小减小，从而因遗传漂变而丧失遗传变异。波罗的海墨角藻科植物是重要的栖息地形成物种，其遗传结构和克隆性的存在对保护策略具有重要意义。
