Biological Invasions

, Volume 15, Issue 11, pp 2455–2465 | Cite as

Patterns of weed invasion: evidence from the spatial genetic structure of Raphanus raphanistrum

  • A. Barnaud
  • J. M. Kalwij
  • M. A. McGeoch
  • B. Jansen van VuurenEmail author
Original Paper


Knowledge of the pathways of colonization is critical for risk assessment and management of weeds. In this study we adopted a landscape genetics approach to assess the impact of human disturbances and large-scale environmental features on the colonization of a global agricultural weed, Raphanus raphanistrum. We used nuclear microsatellite and chloroplast DNA sequence data to quantify the pattern of genetic diversity in 336 plants collected from 13 sites throughout the Cape Floristic Region, South Africa, one of the world’s recognized global biodiversity hotspots. The lack of strong spatial genetic structure suggests that R. raphanistrum colonized throughout the Cape Floristic Region via both local diffusive spread and long-distance jump dispersal. Furthermore, 47 % of analyzed plants contained Raphanus sativus (cultivated radish) chloroplast genomes, indicating historical and/or contemporary gene flow between wild and cultivated radish populations. The prevalence of high genetic diversity and long-distance gene flow are discussed in the context of ecological risk assessment.


Chloroplast DNA Fynbos Introgression Microsatellites Spatial genetic structure Wild radish 



AB was supported through the DST-NRF Centre of Excellence for Invasion Biology, and JMK by the European Union through the European Regional Development Fund (Centre of Excellence FIBIR). We are grateful to S. Bottalico for sampling assistance and to J. Honing for help with DNA extractions. Genotyping was done at Stellenbosch University’s Central Analytical Facility.

Supplementary material

10530_2013_465_MOESM1_ESM.docx (16 kb)
Supplementary material 1 (DOCX 15 kb)


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Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  • A. Barnaud
    • 1
    • 2
  • J. M. Kalwij
    • 3
    • 4
  • M. A. McGeoch
    • 5
  • B. Jansen van Vuuren
    • 4
    Email author
  1. 1.Centre for Invasion Biology, Department of Botany and ZoologyStellenbosch UniversityStellenboschSouth Africa
  2. 2.Diversité Adaptation et Développement des plantes, IRDMontpellierFrance
  3. 3.Institute of Ecology and Earth SciencesUniversity of TartuTartuEstonia
  4. 4.Centre for Invasion Biology, Department of ZoologyUniversity of JohannesburgJohannesburgSouth Africa
  5. 5.Centre for Invasion Biology, School of Biological SciencesMonash UniversityMelbourneAustralia

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