cpDNA evidence of introgressions in Quercus L. (Fagaceae). The influence of the phytotopographic position

Genetic variability of species can appear due to different ecological factors, such as the position they occupy within vegetal communities. From an area in the southern Iberian Peninsula where a great number of species of the genus Quercus are found, we report the influence of winds on their chloroplast DNA (cpDNA) composition. Quercus faginea behaves as the genetic receiver of Q. canariensis, producing the hybrid Q. canariensis×Q. faginea, which is important in the landscape. Both species and the hybrid have a suitable altitudinal location for the pollen route, favoured by eastern winds. Quercus pyrenaica forests are protected from the eastern winds so they receive pollen from Q. lusitanica, favoured by western winds. The hybrids between Q. canariensis and Q. faginea are morphologically identifiable, while the introgressions between Q. lusitanica and Q. pyrenaica are not.