Allozyme characterisation of four Mediterranean evergreen oak species

Polymorphism at 11 enzyme loci was used to compare the four evergreen oak s pecies of the Mediterranean Basin and to establish their taxonomical relati onships. As a comparison, two evergreen oak species from Tibet, located in the primary distribution area of evergreen oaks, were analysed at the same loci. Cladistic analyses led to the separation of a cluster of four species , namely the three Mediterranean Q. ilex, Q. coccifera and Q. alnifolia and the Tibetan Q. aquifolioides. The other Tibetan species, Q. semicarpifolia , and Q. suber, from the Western Mediterranean Basin, were very distinct ge netically from the four other species. These results were not consistent wi th previous taxonomical treatment. based on morphology alone, which classif ied Q. ilex and Q. coccifera in "ilex group" (= subgenus Sclerophyllodrys O . Schwartz), acid the other four species in "cerris group" (subgenus Cerris , according to Schwartz). Allozyme variation has thus provided useful infor mation to clarify the taxonomy of evergreen oaks. (C) 2001 Elsevier Science Ltd. All rights reserved.