@article {130,
	title = {Presence of Triploids among Oak Species},
	journal = {Annals of Botany (London)},
	volume = {99},
	year = {2007},
	month = {2007},
	pages = {959-964},
	abstract = {Background and Aims: Polyploids, organisms that have multiple sets of chromosomes, are common in certain plant and animal taxa. However, there are only a few reports of intraspecific ploidy variation within the genus Quercus. The aim of the study was to investigate the suspected ploidy level of two oaks that have unusual microsatellite banding patterns.Methods: Polyploidy was investigated by using microsatellite analysis, stomata length measurements and nuclear DNA content estimation by flow cytometry. Key Results: Each putative triploid tree has patterns of microsatellite variation unexpected for diploid genomes, with up to three alleles at some loci, significantly longer stomata and 1},
	author = {Dzialuk, A. and Chybicki, I. and Welc, M. and liwiska, E. and Burczyk, J.}
}
@article {75,
	title = {Species Distinction in Irish Populations of Quercus petraea and Q. robur: Morphological versus Molecular Analyses},
	journal = {Annals of Botany (London)},
	volume = {96},
	year = {2005},
	month = {2005},
	pages = {1237-1246},
	author = {Kelleher, C.T. and Hodkinson, T. and Douglas, G. and Kelly, D.}
}
@article {66,
	title = {Coincidence of Small-scale Spatial Discontinuities in Leaf Morphology and Nuclear Microsatellite Variation of Quercus petraea and Q. robur in a Mixed Forest},
	journal = {Annals of Botany (London)},
	volume = {99},
	year = {2007},
	month = {2007},
	pages = {713-722},
	abstract = {Background and AimsThe taxon complex comprising Quercus petraea and Q. robur shows distinct morphologies and ecological preferences, but mostly low differentiation in various types of molecular markers at a broad spatial range. Local, spatially explicit analyses may reveal patterns induced by microevolutionary processes operating mainly over short distances. However, no attempts have been made to date to explore the potential of spatial analyses combining morphological and genetic data of these oaks. Methods A mixed oak stand was studied to elucidate the small-scale population genetic structure. All adult individuals were classified and putative hybrids were identified using multivariate discrimination analysis of leaf morphological characters. Likewise, all trees were genotyped with five nuclear microsatellites, and a Bayesian assignment method was applied based on maximum likelihood of multilocus genotypes for taxon and putative hybrid classification. Key Results Multivariate analyses of leaf morphological data recognized two groups with few individuals as putative hybrids. These groups were significantly differentiated at the five microsatellites, and genetic taxon assignment coincided well with morphological classification. Furthermore, most putative hybrids were assigned to the taxon found in their spatial neighbourhood. When grouping trees into clusters according to their spatial positions, these clusters were clearly dominated by one taxon. Discontinuities in morphological and genetic distance matrices among these clusters showed high congruence. Conclusions The spatial-genetic analyses and the available literature led to the assumption that reproductive barriers, assortative mating, limited seed dispersal and microsite-induced selection in favour of the locally adapted taxon at the juvenile stage may reinforce taxon-specific spatial aggregation that fosters species separation. Thus, the results tend to support the hypothesis that Q. petraea and Q. robur are distinct taxa which share a recent common ancestry. Occasional hybrids are rarely found in adults owing to selection during establishment of juveniles.},
	url = {http://aob.oxfordjournals.org/cgi/content/abstract/99/4/713},
	author = {Gugerli, F. and Walser, J.-C. and Dounavi, K. and Holderegger, R. and Finkeldey, R.}
}
