Morphological Differentiation and Hybridization between Quercus alnifolia Poech and Quercus coccifera L. (Fagaceae) in Cyprus

Analysis of morphological traits was carried out in order to provide insights regarding differentiation and hybridization between two evergreen oak species, the golden oak (Quercus alnifolia Poech) and the holly oak (Quercus coccifera L.) in Cyprus. The holly oak shows a higher degree of morphological diversity, in comparison to the endemic golden oak, which is confined to the ultrabasic rock formations of the Troodos Massif. The parental species can be clearly distinguished. Each species forms both pure and sympatric populations; no significant differences were observed at the within species level. Analysis of mixed stands indicates active but limited genetic introgression and hybridization between the two oaks. Designated hybrids form a distinct group in multivariate space being morphologically closer to the golden oak. Backcrossing events have been implicated from multivariate analysis, while hybrids appear to be more similar to Q. alnifolia.