In vitro response of commercially valuable cultivars of Morus species to thidiazuron and activated charcoal

Towards developing a rapid and reliable in vitro regeneration system for the propagation of mulberry, culture response of Morus multicaulis cv. Goshoerami and M. indica cvs. K2, RFS175 and S1, was examined. The presence of a cytokinin was essential for bud break. Thidiazuron (TDZ) at a concentration of 0.1 mgl-1 was found to be more effective than BAP for bud break and shoot proliferation in M. indica cvs. RFS175 and k2, whereas 0.5 mgl-1 TDZ was better than BAP in M. indica cv. S1. Although TDZ enhanced the efficiency of shoot multiplication in M. indica, 2.5 mgl-1 BAP was found to be superior in the case of M. multicaulis. TDZ not only significantly reduced the days required for bud break but also increased the percentage of bud breaks and the number of shoots per explant in M. indica. In vitro rooting of Morus shoots improved significantly by adding activated charcoal to culture media. A significant increase in the percentage of rooting and a decrease in the days required for rooting were observed by using 0.05% activated charcoal in M. multicaulis cv. Goshoerami and M. indica cv. S1, and 0.1% activated charcoal in M. indica cvs. K2 and RFS175. In vitro-raised plantlets were successfully acclimatized and transferred to the field