1. Department of Plant Biology and Pathology, University of Bari, Via E. Orabona 4, 70126 Bari, Italy
2. Institute for Marine Coastal Environment, Talassografico “A. Cerruti”-C.N.R., Via Roma 3, 74100 Taranto, Italy
3. Department of Botany of the University of Catania, Via A. Longo 19, 95125 Catania, Italy