Evolutionary Ecology

, Volume 31, Issue 4, pp 401–420 | Cite as

Lost in the hybridisation vortex: high-elevation Senecio hercynicus (Compositae, Senecioneae) is genetically swamped by its congener S. ovatus in the Bavarian Forest National Park (SE Germany)

  • Manuela BogEmail author
  • Claus Bässler
  • Christoph Oberprieler
Original Paper


Hybridisation is an important evolutionary process. The investigation of hybridisation along elevational gradients, with their steep abiotic and biotic clines, provides insight into the adaptation and maintenance of species in adjacent habitats. The rare Senecio hercynicus and its spreading congener S. ovatus are vertically vicariant species that show hybridisation in their range overlaps. In the present study, we used AFLP fingerprinting of 689 individuals from 38 populations to analyse population structure and introgression patterns along four elevational transects (650–1350 m) in the Bavarian Forest National Park, Gemany. Subsequently, we searched for loci putatively under divergent selection that may maintain ‘pure’ species despite hybrid formation by identifying taxon-specific alleles. A maximum-likelihood based hybrid index shows that the overall genetic differentiation among all populations was very low with a vanishingly small number of pure parental individuals. Almost 75% of the investigated individuals were classified as backcrosses towards S. ovatus. The highest S. hercynicus ancestry was found in the uppermost populations of two transects. Further, we found seven taxon-specific alleles being under divergent selection that correlated with climatic variables and deviating from neutral introgression. According to our results, hybridisation of S. ovatus and S. hercynicus has reached an advanced state of genetic swamping and there seems to be no driving force that is strong enough to keep both species as different lineages. Rather, S. ovatus appears to benefit through putatively adaptive introgression.


Amplified fragment length polymorphism (AFLP) Adaptive introgression Hybridisation Natural selection Population genomics Senecio nemorensis syngameon 



The help of Gabriel Heine in sampling and DNA extraction, Peter Hummel for technical assistance in the molecular laboratory of C.O., and Ulrich Lautenschlager for generating the 0/1-matrix is gratefully acknowledged. Financial support for the molecular studies partly came from Bavarian Forest National Park. Comments of two anonymous reviewers improved the contribution considerably.

Supplementary material

10682_2017_9890_MOESM1_ESM.pdf (260 kb)
Fig. S1 Results of a Bayesian cluster analysis based on AFLP fingerprinting using the software programme Structure (pdf file). (PDF 260 kb)
10682_2017_9890_MOESM2_ESM.pdf (1.4 mb)
Fig. S2 Fitted genomic clines for all 59 tested loci (pdf file). (PDF 1388 kb)
10682_2017_9890_MOESM3_ESM.xlsx (151 kb)
Table S1 Characterisation of all 681 AFLP loci by MCHEZA, BayeScan, Samβada and introgress (xlsx file). (XLSX 151 kb)


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Copyright information

© Springer International Publishing Switzerland 2017

Authors and Affiliations

  1. 1.Evolutionary and Systematic Botany, Institute of Plant SciencesUniversity of RegensburgRegensburgGermany
  2. 2.General Botany and Plant Systematics, Institute of Botany and Landscape EcologyErnst Moritz Arndt UniversityGreifswaldGermany
  3. 3.Bavarian Forest National ParkGrafenauGermany

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