The sutsuki azaleas (Rhododendron indicum) family Ericaceae as bonsai, grown in the ground or as pot plants.
Satsuki evergreen azaleas have been hybridized in Japan for at least 500 years.
R.indicum one of the oldest and most famous ever green azaleas, bred since ancient times and they are the type
most commonly used for ornamental pruning.
In vitro propagation from meristematic tissues is a suitable method for production of Rhododendrons and
Azaleas; Their propagation by conventional methods (seeds,cuttings,etc.) is either difficult or infective [20].
The commercial production of ornamental plants is growing worldwide. It is monetary value has significantly
increased over the last two decades and there is a great potential for continued further growth in both domestic and
international markets [11]. According to a report, in 2004, German in vitro laboratories produced more than 31
million plants of orchids. Other important plant genera are Rhododendron (1.0 million) [21].
One of the major factors affecting the success of in vitro plant propagation is the choice of plant growth
regulators (PGRs). As a result, PGRs (especially cytokinins) are often added to culture media for the purpose of
controlling different physiological responses in vitro, leading to the production of tissues (such as callus) organs
(such as shoots and roots) or whole plants [2].
The development of auxiliary meristems is dependent on the presence of growth regulators in culture medium
[10]. Therefore according to reports related to propagation of azalea, typically are used limited levels of different
concentrations 2ip, Zeatin and TDZ. Moreover, there are many reports showing that the application of TDZ results
in a better shoot regeneration capacity in comparison with other cytokinins [19]. The presence of 1.5 μM TDZ with
2.3 μM Zeatin improved regeneration in evergreen azaleas [8]. Lower cytokinin concentrations have the best effect
on shoot regeneration in azaleas. In other research, has reported 5 mg/l Zeatin singly, was the best concentration
for the shoot induction evergreen azalea [6].
The objective of study was to find the most effective concentration of growth regulators on shoot proliferation
and node formation of Rododendron indicum.