Oecologia

, Volume 158, Issue 3, pp 463–472

Niche differentiation between diploid and hexaploid Aster amellus

  • Jana Raabová
  • Markus Fischer
  • Zuzana Münzbergová
Population Ecology - Original Paper

Abstract

The maintenance of separated diploid and polyploid populations within a contact zone is possible due to both prezygotic and postzygotic isolation mechanisms. Niche differentiation between two cytotypes may be an important prezygotic isolating mechanism and can be studied using reciprocal transplant experiments. We investigated niche differentiation between diploid and hexaploid Aster amellus in their contact zone in the Czech Republic. Diploid populations are confined to habitats with low productivity, whereas hexaploid populations occur in habitats with both low and high productivity. Thus, we chose three diploid populations and six hexaploid populations, three in each of the two different habitat types. We analyzed habitat characteristics and carried out reciprocal transplant experiments in the field using both seeds and adult plants. Sites of diploid and hexaploid populations differed significantly in vegetation and soil properties. The mean number of juveniles was higher at sites of home ploidy level than at sites of foreign ploidy level, suggesting niche differentiation between the two cytotypes. On the other hand, transplanted adult plants survived at all sites and juvenile plants were able to establish at some sites of the foreign cytotype. Furthermore, the mean number of juveniles, survival, and flowering percentages were higher at home sites than at foreign sites, indicating local adaptation. We conclude that niche differentiation between the two cytotypes and local adaptation within each cytotype may contribute to the maintenance of diploid and hexaploid populations of A. amellus in their contact zone. Moreover, further factors, such as differences in flowering phenology and exclusion of minority cytotypes, should also be considered.

Keywords

Cytotype distribution Local adaptation Polyploidy Reciprocal transplant Secondary contact zone 

Supplementary material

442_2008_1156_MOESM1_ESM.doc (388 kb)
Electronic supplementary material S1 (DOC 388 kb)

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Jana Raabová
    • 1
    • 5
  • Markus Fischer
    • 2
    • 3
  • Zuzana Münzbergová
    • 1
    • 4
  1. 1.Department of Botany, Faculty of ScienceCharles UniversityPragueCzech Republic
  2. 2.Institute of Plant SciencesUniversity of BernBernSwitzerland
  3. 3.Institute for Biochemistry and BiologyUniversity of PotsdamPotsdamGermany
  4. 4.Institute of BotanyAcademy of Sciences of the Czech RepublicPrůhoniceCzech Republic
  5. 5.Department of BotanyNational MuseumPrůhoniceCzech Republic

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