The effect of plant growth regulators and their concentration in vitro on mass poropagation of Myrobalan 29C rootstock

Myrobalan 29C is one of the most important rootstocks that is widely used for plum and apricot trees. This study was conducted to determine the most suitable media culture and regulators of plant growth for micropropagation of Myrobalan 29C in Khorasan Natural Resource and Agricultural Research Centre Mashhad, Iran. 10 explants treated were sterilized in 70% Ethanol for 1 min, Mercuric chloride (0.1%) for 1, 2 and 3 min and sodium hypochlorite (3 and 10%) for 10, 20 and 30 min. Results showed that 10% sodium hypochlorite (30 min) with 2% decay was the best treatment. In this experiment,  proliferation and rooting were performed in three kinds of culture media: Murashige and Skoog (MS), McCown and Lioyd (WPM) and Driver and Kuniyuki (DKW). They were supplemented with plant growth regulators (benzyl amino purine (BAP) and thiadizuron (TDZ)) of 0, 1, 2, 3, 4 mg l-1 in all treatments of the proliferation; and with indole-3-butyric acid (IBA) and naphthalene acetic acid (NAA) of 0, 1, 2, 3 mg l-1 in the rooting step. Results showed that the highest number and length of shoot respectively were 5.58 and 2.50 cm in MS medium with 2 mg l-1 BAP concentrations. The DKW medium in 1 mg l-1 of NAA, the highest percent of rooting (100%) and root length were about 14.5 cm in MS medium with 2 mg l-1 of NAA respectively. The acclimatization of plantlets was successful in greenhouse conditions. The survival percent in substrateperlite (100% V) was about 80%.   Key words: Tissue culture, disinfection, micropropagation, acclimatization.