In vitro PROPAGATION AND ROOTING OF GARNEM ROOTSTOCK

‘Garnem’ is a clonal hybrid (Prunus amygdalus × Prunus persica) for almond, peach and plum. It is resistant to nematodes and frequently used in orchards. In the present study, interactive effects of different culture media and different concentrations of growth regulators on micropropagation of Garnem rootstock were investigated. Stem cuttings of current season's growth were taken from matured stock plants and cultured on establishment medium after disinfection. After four weeks, elongated shoots were cut and subcultured on proliferation media including Murashige and Skoog (MS) and ME supplemented with four 6-benzyladenine (BA) concentrations. Medium and BA concentration significantly affected both number shoots and shoot length. Maximum number of shoots were observed on MS medium (2.98 shoots per explants), which also induced the highest length of shoots (2.81 cm). The highest number of shoots (4.03 shoots per explants) and shoot length (3.54 cm) were obtained with 2 mg L-1 of BA. Furthermore, shoot length was influenced by interaction between medium and BA level, whereas number of shoots was independent of this interaction. As a result, the highest rate of multiplication achieved on MS medium supplemented with 2 mg L-1 of BA. For rooting, in vitro proliferated and elongated shoots were planted on Quoirin and Lepoivre (QL) medium containing 0.5, 1 and 1.5 mg L-1 of indole-3-butyricacid (IBA). High rooting percentage, root length and root number were obtained with all concentrations of IBA. However, 0.5 mg L-1 of IBA produced less callus than 1 and 1.5 mg L-1 of IBA. The in vitro plantlets were transferred to the soil and the survival rate ex vitro was 95%.