Hybridization of European oaks (Quercus ilex x Q-robur) results in a mixed isoprenoid emitter type

European oaks have been reported to emit isoprene or monoterpenes derived from recently fixed photosynthetic carbon. The emission type is plant species specific and can be used as chemo-taxonomic marker. In the present article the isoprenoid biochemical properties of mature Quercus x turneri'Pseudoturneri' hybrids resulting from a crossing of a Mediterranean evergreen monoterpene-emitting species (subgenus Sclerophyllodrys; Quercus ilex L.) and an isoprene-emitting deciduous oak species (subgenus Lepidobalanus; Quercus robur L.) are described. Both species are compared with respect to the capacity for isoprenoid synthesis and the actual isoprenoid emission pattern of different tree-types. The analysis showed that the oak hybrid combines properties of both parental species. Furthermore, it could be shown that the enzyme activities of isoprene synthase and monoterpene synthases are reflected in the isoprenoid emission pattern of the hybrids as well as in the observed emission rates.