AOBPreview originally published online on September 30, 2005
Annals of Botany 2005 96(7):1237-1246; doi:10.1093/aob/mci275
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Species Distinction in Irish Populations of Quercus petraea and Q. robur: Morphological versus Molecular Analyses
1 Department of Botany, Trinity College, School of Natural Sciences, University of Dublin, Dublin 2, Ireland and 2 Teagasc, Kinsealy Research and Development Centre, Malahide Road, Dublin 17, Ireland
* For correspondence. E-mail ckellehe{at}interchange.ubc.ca
Received: 3 May 2005 Returned for revision: 21 June 2005 Accepted: 22 August 2005 Published electronically: 30 September 2005
• Background and Aims Populations of oak (Quercus petraea and Q. robur) were investigated using morphological and molecular (AFLP) analyses to assess species distinction. The study aimed to describe species distinction in Irish oak populations and to situate this in a European context.
• Methods Populations were sampled from across the range of the island of Ireland. Leaf morphological characters were analysed through clustering and ordination methods. Putative neutral molecular markers (AFLPs) were used to analyse the molecular variation. Cluster and ordination analyses were also performed on the AFLP markers in addition to calculations of genetic diversity and F-statisitcs.
• Key Results A notable divergence was uncovered between the morphological and molecular analyses. The morphological analysis clearly differentiated individuals into their respective species, whereas the molecular analysis did not. Twenty species-specific AFLP markers were observed from 123 plants in 24 populations but none of these was species-diagnostic. Principal Coordinate Analysis of the AFLP data revealed a clustering, across the first two axes, of individuals according to population rather than according to species. High FST values calculated from AFLP markers also indicated population differentiation (FST = 0·271). Species differentiation accounted for only 13 % of the variation in diversity compared with population differentiation, which accounted for 27 %.
• Conclusions The results show that neutral molecular variation is partitioned more strongly between populations than between species. Although this could indicate that the populations of Q. petraea and Q. robur studied may not be distinct species at a molecular level, it is proposed that the difficulty in distinguishing the species in Irish oak populations using AFLP markers is due to population differentiation masking species differences. This could result from non-random mating in small, fragmented woodland populations. Hybridization and introgression between the species could also have a significant role.
Key words: Species differentiation, pedunculate oak, sessile oak, AFLP, Quercus petraea, Quercus robur
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  G. E. McKinnon, R. E. Vaillancourt, D. A. Steane, and B. M. Potts An AFLP marker approach to lower-level systematics in Eucalyptus (Myrtaceae) Am. J. Botany, March 1, 2008; 95(3): 368 - 380. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Gugerli, J.-C. Walser, K. Dounavi, R. Holderegger, and R. Finkeldey Coincidence of Small-scale Spatial Discontinuities in Leaf Morphology and Nuclear Microsatellite Variation of Quercus petraea and Q. robur in a Mixed Forest Ann. Bot., April 1, 2007; 99(4): 713 - 722. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Yatabe, N. C. Kane, C. Scotti-Saintagne, and L. H. Rieseberg Rampant Gene Exchange Across a Strong Reproductive Barrier Between the Annual Sunflowers, Helianthus annuus and H. petiolaris Genetics, April 1, 2007; 175(4): 1883 - 1893. [Abstract] [Full Text] [PDF]
|
|