Abstract
Hazel (Corylus avellana) has been a key species in European woodlands throughout the Holocene (10 KYA–present). Like many tree species, it is increasingly under threat from climate change, habitat loss and fragmentation, invasive species and emergent pathogens. As knowledge of the genetic structure of natural populations of trees is vital for managing these threats, as well as an essential basis for selection of material for replanting and restocking, we analysed levels and patterns of genetic diversity in the species at a range of spatial scales using high-resolution microsatellite markers. Our findings indicate that hazel populations exhibit high levels of genetic diversity along with low levels of population differentiation, suggesting extensive gene flow. Fine-scale genetic structuring was observed in some of the woodlands studied, probably resulting from restricted dispersal of the heavy nuts produced by the species. This, coupled with higher levels of pollen-mediated gene flow, resulted in a weak but significant pattern of isolation by distance. These results suggest that replanting following potential loss of hazel populations may not necessarily require the use of material from the same locality and mirror findings in other broadleaved tree species from the same area.
Highlights
Hazel, Corylus avellana, has historically been a major component of woodlands across Europe and especially so in Great Britain and Ireland
The results of this study suggest that the common hazel in Northern Ireland and Ireland as a whole maintains high levels of genetic diversity along with low levels of population differentiation resulting from high levels of gene flow
Whilst there have been several studies on C. avellana, the present study is the first to look at natural populations of hazel using high-resolution, codominant nuclear microsatellite markers, in contrast with those which have used low resolution and/or dominant markers (allozymes and amplified fragment length polymorphisms (AFLPs)) or those which have focused on the genetics of cultivated varieties
Summary
Corylus avellana, has historically been a major component of woodlands across Europe and especially so in Great Britain and Ireland. Pollen records suggest that hazel was one of the first species to re-colonize Europe after the last ice age (Huntley and Birks 1983; Huntley 1993), and the species’ present-day natural geographic distribution is extensive, ranging from southern Norway and Finland to the north, the Ural mountains of Russia to the east, northern Iberia to the west and Morocco to the south. Deciduous shrub that grows mainly in forests and in hedgerows. It is wind pollinated and monoecious but has mechanisms to prevent selfing, including dichogamy and sporophytic incompatibility (Thompson 1979). Its morphology is highly polymorphic, with the previously described species Corylus maxima, Corylus pontica and Corylus colchica being included as members of
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
