Skip to Main Content
Leaf morphological and genetic differentiation between Quercus rubra L. and Q. ellipsoidalis E.J. Hill populations in contrasting environmentsAuthor(s): Oliver Gailing; Jennifer Lind; Erik Lilleskov
Source: Plant Systematics and Evolution. 298(8): 1533-1545.
Publication Series: Scientific Journal (JRNL)
Station: Northern Research Station
Download Publication (501.0 KB)
DescriptionHybridization is considered to play an important role in speciation and evolution. Given the predicted northward tree migration in the eastern USA due to the impact of climate change, hybridization between related species is expected to become more frequent due to overlapping distribution ranges in the future. Oak species are "hot spots" of contemporary hybridization, serving as model organisms in the development of ecological species concepts. Q. rubra L. and Q. ellipsoidalis E.J. Hill were selected as study species, since they show different ecological requirements but hybridize with each other where both species co-occur. To identify morphological species and differentiation patterns in this species pair in ten populations on the Upper Peninsula of Michigan we investigated both leaf morphological variation, and genetic variation at highly variable microsatellite markers. Cluster analyses using leaf morphological characters revealed two distinct clusters for directly measured leaf characters and three clusters when additionally leaf shape characters were considered. Two populations growing on dry and sandy sites and identified as Q. ellipsoidalis in the field and by genetic assignment analyses were differentiated from the other eight populations at leaf morphological characters. Strong and significant correlations of leaf morphological differences with genetic distances at microsatellite markers but not with geographic distances are consistent with a pattern of isolation by adaptation. Differentiation at genetic and leaf morphological characters between neighboring populations in contrasting environments suggested reproductive isolation between populations of different species, possibly as the result of divergent selection. More extensive sampling along the distribution range of both species and reciprocal transplant experiments between parental environments are necessary to better understand the role of interspecific gene flow and selection in the maintenance of species identity in red oak species (Quercus section Lobatae).
- Check the Northern Research Station web site to request a printed copy of this publication.
- Our on-line publications are scanned and captured using Adobe Acrobat.
- During the capture process some typographical errors may occur.
- Please contact Sharon Hobrla, firstname.lastname@example.org if you notice any errors which make this publication unusable.
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationGailing, Oliver; Lind, Jennifer; Lilleskov, Erik. 2012. Leaf morphological and genetic differentiation between Quercus rubra L. and Q. ellipsoidalis E.J. Hill populations in contrasting environments. Plant Systematics and Evolution. 298(8): 1533-1545.
KeywordsQuercus rubra, Q. ellipsoidalis, Hybridization, Leaf morphology, EST–SSRs
- Shade, leaf growth, and crown development of Quercus rubra, Q. velutina, Prunus serotina, and Acer rubrum seedlings
- Partitioning of current photosynthate to different chemical fractions in leaves, stems, and roots of northern red oak seedlings during episodic growth
- Sustaining northern red oak forests: managing oak from regeneration to canopy dominance in mature stands
XML: View XML