SHOOT REGENERATION FROM LEAF EXPLANTS OF DWARFING APPLE ROOTSTOCKS

Leaves from micropropagated shoots were cultured on MS, B5, and modified N6 basal media solidified with Gelrite or agar. MS with Gelrite was the best supporting medium for adventitious shoot formation followed by B5 and modified N6. Optimum regeneration occurred on MS basal medium supplemented with 10-mu-M BAP, 1-mu-M NAA and 3 % sucrose. The morphogenetic capacity of a leaf segment was dependent on leaf maturity and the origin of the segment. Folded and young expanding leaves were more responsive than older leaves. Basal and middle leaf segments were more prolific than the tip. Cultivar M9 showed higher regenerative capacity (79 %) than Ottawa 3 (63 %).