Abstract: The organogenesis characteristics of app le (M alus dom estica Borkh. ) shoot exp lants repeated
ly subcultured in vitro were examined by analysis of the shootmultip lication, rooting, and adventitious bud re
generation rate from leaves. The results showed low p ropagation ability for the shoot exp lants subcultured in
vitro for five times or less at the beginning of inoculation in terms of its shootmultip lication, rooting, and ad
ventitious bud regeneration rate from leaves. With the increasing number of subculturing times, the regenera
tion ability of the organs above enhanced and remaind at a high level. There were no significant differences a
mong the shoot p lantlets being subcultured for 76 and 164 times in Fuji, and for 76, 84, and 116 times in
Golden Delicious and Jonagold in the aspects of above. It is concluded that the app le shoot p lantlets repeatedly
subcultured in vitro formore than one hundred times for twenty years retain the organogenesis characteristics as
usual and can still be used for the p lantmicrop ropagation and gene transformation.

Key words: Apple, Subculture times, Shootmultip lication, Rooting, Adventitious bud regeneration