Local adaptation through countergradient selection in northern populations of Skeletonema marinoi

Research output: Contribution to journalJournal articlepeer-review

Documents

  • Fulltext

    Final published version, 552 KB, PDF document

  • Josefin Sefbom
  • Anke Kremp
  • Hansen, Per Juel
  • Kerstin Johannesson
  • Anna Godhe
  • Karin Rengefors

Marine microorganisms have the potential to disperse widely with few obvious barriers to gene flow. However, among microalgae, several studies have demonstrated that species can be highly genetically structured with limited gene flow among populations, despite hydrographic connectivity. Ecological differentiation and local adaptation have been suggested as drivers of such population structure. Here we tested whether multiple strains from two genetically distinct Baltic Sea populations of the diatom Skeletonema marinoi showed evidence of local adaptation to their local environments: the estuarine Bothnian Sea and the marine Kattegat Sea. We performed reciprocal transplants of multiple strains between culture media based on water from the respective environments, and we also allowed competition between strains of estuarine and marine origin in both salinities. When grown alone, both marine and estuarine strains performed best in the high-salinity environment, and estuarine strains always grew faster than marine strains. This result suggests local adaptation through countergradient selection, that is, genetic effects counteract environmental effects. However, the higher growth rate of the estuarine strains appears to have a cost in the marine environment and when strains were allowed to compete, marine strains performed better than estuarine strains in the marine environment. Thus, other traits are likely to also affect fitness. We provide evidence that tolerance to pH could be involved and that estuarine strains that are adapted to a more fluctuating pH continue growing at higher pH than marine strains.

Original languageEnglish
JournalEvolutionary Applications
Volume16
Issue number2
Number of pages10
ISSN1752-4563
DOIs
Publication statusPublished - 2023

Bibliographical note

Publisher Copyright:
© 2022 The Authors. Evolutionary Applications published by John Wiley & Sons Ltd.

    Research areas

  • countergradient variation, diatom, intraspecific competition, local adaptation, pH, phenotypic plasticity, salinity

ID: 315983118