Phenotypic and genetic variation in natural populations of Festuca rubra s.l. in Europe

ABSTRACT

Background: Phenotypic variation within species challenges the identification of meaningful taxonomic units and the quantification of evolutionarily relevant biodiversity.

Aims: We studied usefulness of the present taxonomic classification of species and subspecies within Festuca rubra complex.

Methods: We categorised F. rubra s. l. plants collected from natural populations across Europe such as the endemic species of F. rothmaleri and F. rubra subspecies (subsp. rubra and arctica) or between-subspecies hybrids (arctica × rubra). The plants were grown in a common garden, which was followed by an examination of variation in regard to 17 morphological traits, ploidy levels, nuclear ribosomal DNA, and chloroplast DNA.

Results: Phenotypic and cpDNA markers demonstrated stronger differentiation between geographic regions than between species or subspecies. Of the morphological traits, only lemma hairiness distinguished between F. rubra subspecies. Ploidy level varied within the F. rothmaleri and F.rubra subspecies. cpDNA and nrDNA markers showed no genetic differentiation among the F. rubra subspecies and their hybrids but clustered F. rubra taxa and F.rothmaleri as separate groups. Several additive polymorphic sites in nrDNA sequences indicated hybridisation in the F. rubra taxa.

Conclusion: Commonly used traits may not be reliable in determining evolutionary relevant taxonomic entities within F. rubra complex.

KEYWORDS:

• Fungal endophytes
• grasses
• morphology
• phenotypic plasticity
• ploidy

Acknowledgements

This work was supported by INTERACT (grant agreement No. 262693) under the European Community’s Seventh Framework Programme and the Academy of Finland Grants 137909, 295976, and 326226.

Data availability

Data will be deposited in the Dryad digital repository. The ITS sequences have been submitted to the National Centre for Biotechnology Information database (GenBank).

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed here

Additional information

Funding

This work was supported by the Academy of Finland [137909,295976,326226]; Seventh Framework Programme INTERACT [262693].

Notes on contributors

Kari Saikkonen

Kari Saikkonen is a research professor. His expertise includes impacts of climate change on plant protection, integrated pest and pathogen management and plant-microbe-herbivore interactions.

Serdar Dirihan

Serdar Dirihan is a post-doctoral researcher. His research interests include grass-endophyte interactions and ploidy level analyses of plants.

Henry Väre

Henry Väre is a senior curator specialized on plant taxonomy.

Irma Saloniemi

Irma Saloniemi is a lecturer with interest in evolutionary genetics and biostatistics.

Maria Cräutlein

Maria Cräutlein is a senior scientist in plant and fungal molecular genetics.

Päivi H. Leinonen

Päivi H. Leinonen is a senior scientist and works on population genetics and studies the heritability of adaptive traits in Festuca in changing climate.

Marjo Helander

Marjo Helander is a researcher of trophic interactions among microbes, plants and herbivores.