Complex spatial clonal structure in the macroalgae Fucus radicans with both sexual and asexual recruitment

Ecology and Evolution

Angelica Ardehed³  Daniel Johansson³  Ellen Schagerström²  Lena Kautsky²  Kerstin Johannesson¹ 

[1] Department of Marine Sciences-Tjärnö, University of Gothenburg, Strömstad, Sweden;Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden;Department of Biology and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden

关键词: asexual reproduction;    clonality;    macroalgae;    microsatellites;    somatic mutations;   

DOI  :  10.1002/ece3.1629

来源: Wiley

【 摘 要 】

Abstract

In dioecious species with both sexual and asexual reproduction, the spatial distribution of individual clones affects the potential for sexual reproduction and local adaptation. The seaweed Fucus radicans, endemic to the Baltic Sea, has separate sexes, but new attached thalli may also form asexually. We mapped the spatial distribution of clones (multilocus genotypes, MLGs) over macrogeographic (>500 km) and microgeographic (<100 m) scales in the Baltic Sea to assess the relationship between clonal spatial structure, sexual recruitment, and the potential for natural selection. Sexual recruitment was predominant in some areas, while in others asexual recruitment dominated. Where clones of both sexes were locally intermingled, sexual recruitment was nevertheless low. In some highly clonal populations, the sex ratio was strongly skewed due to dominance of one or a few clones of the same sex. The two largest clones (one female and one male) were distributed over 100–550 km of coast and accompanied by small and local MLGs formed by somatic mutations and differing by 1–2 mutations from the large clones. Rare sexual events, occasional long-distance migration, and somatic mutations contribute new genotypic variation potentially available to natural selection. However, dominance of a few very large (and presumably old) clones over extensive spatial and temporal scales suggested that either these have superior traits or natural selection has only been marginally involved in the structuring of genotypes.

【 授权许可】

CC BY   
© 2015 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.

Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.