Molecular fingerprinting evidence (ISSR, Inter-Simple Sequence Repeats) for a wild status of Olea europaea L. (Oleaceae) in the Eurosiberian North of the Iberian Peninsula

Abstract

Although the olive tree ( Olea europaea L.) is one of the best indicators of the Mediterranean region, there exist some isolated populations of this species in the Eurosiberian North of the Iberian Peninsula. To elucidate the wild or feral status of these populations, we studied a total of 46 populations of the Olea europaea complex. mat K sequences and Inter-Simple Sequence Repeats (ISSR) variation were analysed to infer relationships among the six subspecies of the Olea europaea complex and within O. europaea subsp. europaea. Based on mat K. sequences, populations of sspp. europaea (Mediterranean basin), cerasiformis (Madeira), guanchica (Canary Islands), maroccana (Agadir Mountains) and laperrinei (the Sahara) form one group separate from subsp. cuspidata (South and East of Africa, Arabia, Asia). In the parsimony-based (Heuristic) and distance-based (UPGMA and Neighbor Joining) analyses of ISSR variation, populations of the cultivated olive (var. europaea) form two groups which are intermingled with the populations of the wild olive (var. sylvestris ). The four olive populations from the Eurosiberian North of the Iberian Peninsula included in the analysis are closely related to each other and to other Iberian wild populations. This is interpreted as strong evidence for their wild rather than feral status in this area.