METHODS FOR PRODUCING GRAFT CHIMERAS IN VITRO
Several authors report the synthesis of periclinal chimeras generated from graft unions of Solanaceous plants grown in the greenhouse. As this technique requires shoot organogenesis, in vitro conditions are necessary to adapt this technique to woody species. We now report several in vitro techniques necessary to mimic the in vivo graft chimera process. These include rootstock/scion preparation, micrografting and shoot organogenesis from graft unions. Zeatin and auxins have been helpful in preparing graftable material and for increasing the percentage successful grafts. A shorter exposure to organogenic medium containing thidiazuron resulted in greater percentage shoot regeneration from graft unions. Thorny/thornless Rubus and 'Liberty'/'Golden Delicious' or 'Gala' Malus (color) markers are being used to determine the percentage of these regenerants which are chimeral.