In vitro propagation as a tool to enhance the use of native ornamentals in archaeological sites of Greece

This work, as a part of a research programme on the integrated management of vegetation at archaeological sites of Greece, aims at study the micropropagation protocols for small shrubby species belonging to the Greek macchia vegetation. The following species were selected: Anthyllis barba-jovis (A. splendens), A. hermanniae, Atriplex halimus, Ballota acetabulosa, Calamintha cretica, C. nepeta, Lomelosia cretica, L. hymettia, Limoniastrum monopetalum, Teucrium capitatum, Thymelaea hirsute and T. tartonraira. A satisfactory in vitro initiation (80-100%) was obtained using node explants excised from young seedlings grown in vitro. Higher percentage of species (80%) was successfully established on hormone-free (HF) MS medium, but most species showed higher multiplication rate on media supplemented with benzyladenine (BA), kinetin (KIN) and zeatin (ZEA). Shoots grown on multiplication medium supplemented with BA, show the best performance at low BA concentrations (0.25-0.5 mg L^-1); this was not the case for shoots grown on ZEA-media which had satisfactory multiplication at ZEA concentration 1.0-4.0 mg L^-1. When KIN was added to the medium, the best performance was scored for the concentration 2 mg L^-1. The rooting process was genotype-dependent: almost half of the species rooted successfully at 80-100%, while A. halimus showed poor rooting, and T. hirsuta and T. tartonraira failed to root. Although 50% of the species rooted efficiently on HF-half strength MS medium, 3-indolebutyric acid (IBA) increased the rate of rooted species. The highest rate of rooted species (80%) was observed with 1.0 mg L^-1 IBA. Ex vitro acclimatization on a peat:perlite (1:1, v/v) mixture was highly successful (90-100%) for all rooted species.