THE EFFECT OF CULTURE MEDIA AND GROWTH REGULATORS ON PROLIFERATION AND ROOTING OF PLUM ROOTSTOCK ISHTARA

“Ishtara” is a polyvalent rootstock that induces medium vigour and is proper for peach, apricot and plum cultivars. In the present study, the effect of various culture media and concentrations of growth regulators were investigated on the micropropagation of Ishtara. Stems of the current season's growth were excised from matured stock plants, disinfected and cultured on establishment medium. After four weeks, elongated shoots were cut and sub-cultured on proliferation media including the MS, QL and ME that were all supplemented with four BAP concentrations (0, 0.5, 2 and 1 mg L-1). Medium and BAP concentration significantly affected the number of shoots and the shoot lengths. The highest number of shoots was obtained on the MS and ME (4.02 and 3.75 shoots per explants respectively). However, the longest shoots were induced on the MS media (5.781 cm). The highest number of shoots was obtained with the 1 and 2 mg L-1 BAP concentrations (5.133 and 4.733 shoots per explants respectively). Therefore, the highest rate of multiplication was achieved on MS supplemented with 1 mg L-1 of BAP. For rooting, in vitro proliferated and elongated shoots were planted on the QL, MS, LS and the modified LS containing 0.5, 1 and 1.5 mg L-1 of IBA. The highest total root length and root number were obtained with the 1 and 1.5 mg L-1 of IBA concentration and the highest number of roots were observed on the MS and LS. Hence, LS medium with the 1 mg L-1 of IBA concentration was the best medium for rooting. Also, the Acclimatization rate was high due to good quality plants used.