Reduced glutathione promotes callus growth and shoot development in a shoot tip culture of apple root stock M26

Reduced glutathione (GSH) was applied to prevent browning in shoot tip explants of apple (Malus pumila Mill.). Development was compared between shoot tips treated either by (a) dipping into 0.1 mm GSH solution prior to culture (dip treatment), (b) dipping into the GSH solution and transferring to a medium containing 0.1 mm GSH (dip-and-add treatment), or (c) without dipping or culturing with GSH (control). In the dip treatment, 100% of shoot tips developed into normal shoots after 120 days, while the results with the dip-and-add treatment and control were 50 and 40%, respectively. The results show that application of antioxidant GSH in the initial phase of culture promoted the normal development of shoot tips. Received: 10 October 1997 / Revision received: 12 January 1998 / Accepted: 24 January 1998