| heal.abstract |
Arbutus × andrachnoides Link. (A. unedo × A. andrachne) is one of the two hybrids between species of Arbutus genus found in the Mediterranean Macchia zone. It is a drought tolerant, evergreen shrub or small tree with glossy dark green foliage and a cinnamon-red bark that splits in strips revealing the greenish interior. The plant is particularly attractive during the winter period when fruiting with small, strawberry-like orange-red fruits. These features give Arbutus × andrachnoides the potential to be introduced for use in the urban and suburban landscape, as well as for reforestation as it resprouts after fire. In this study the micropropagation of the plant was investigated. For in vitro culture initiation, nodal stem segments were used as explants excised in May from adult plants grown in the wild near Kalamos (Attiki, Greece). Explants were cultured on solid (8 g/L agar) Woody Plant Medium salts with 3% sucrose, 100 mg/L myo-inositol, 1 mg/L thiamine, 0.5 mg/L nicotinic acid and 0.5 mg/L pyridoxine (WPM), supplemented with 2.5 mg/L benzyladenine (BA), kinetin (KIN), 2-isopentenyl adenine (2iP) or zeatin (ZEAT). 70% of the explants cultured in the ZEAT medium produced shoots, while those in the other cytokinins produced shoots at percentages lower than 50%, with a minimum of 25% in KIN. The shoot number produced per explant was not affected by the cytokinin type, but the shoot length and the node number per shoot were two to three times bigger in ZEAT compared to BA and 2iP, while in KIN shoots did not elongate. In the subculture ZEAT was much more effective for shoot multiplication than 2iP giving four times higher multiplication rate, while media supplemented with BA or KIN did not produce any shoots. Therefore, ZEAT proved the most effective cytokinin for culture initiation and multiplication of A. × andrachnoides. 95% of the microshoots rooted in vitro on WPM with 1 mg/L IBA and 80% of the microplants were established successfully ex vitro on 1 perlite:1 compost for ericaceous plants (v/v). |
en |