In vitro propagation of Arbutus unedo var. rubra starting from seedlings and adult parental plants

Shooting of nodal explants excised from two-month old A. unedo var. rubra seedlings was promoted by Woody Plant Medium supplemented with Mullin vitamins (WPM) (100% shooting) compared to Murashige and Skoog (MS) medium (53% shooting), as well as by zeatin (ZEA) at 2.5 or 5.0 mg L^-1 (88% shooting on MS medium, 100% on WPM). Thidiazuron (TDZ) at 0.2 mg L^-1 induced shooting at similar percentages to ZEA, while at 2 mg L^-1 inhibited shooting compared to ZEA (63% on MS medium, 90% on WPM). More shoots per explant (2-3), as well as longer shoots (0.6-0.8 cm) with more nodes (5.0-7.2) were produced on media supplemented with ZEA. Nodal explants excised in early May from young shoots of a wild adult plant and cultured on WPM with 2.5 mg L^-1 ZEA sprouted at lower percentage (63%) and formed less shoots per explant (1.4) compared to seedling-originated explants.
At the shoot multiplication stage, MS medium and WPM were supplemented with 0.5, 2.5 and 10.0 mg L^-1 ΖΕΑ alone or in combination with 0.1 mg L^-1 naphthaleneacetic acid (NAA). In all treatments, almost all the explants produced shoots; the number of shoots per explant remained at the level of the establishment stage (max 3) and the mean shoot length was less than 1 cm.
Microshoot rooting occurred at higher percentages on full- or half-strength WPM (88-94%) compared to full- or half-strength MS medium (32-44%), under 1 or 2 mg L^-1 indole-3-butyric acid (IBA). All plantlets (100%) were successfully acclimatized ex vitro on a mix of peat: perlite 1:1 (v/v).

VI International Conference on Landscape and Urban Horticulture

A. Papagianni, M. Papafotiou, K.F. Bertsouklis

acclimatization, cytokinins, Ericaceae, explant origin, pink strawberry tree

https://doi.org/10.17660/ActaHortic.2017.1189.93