Abstract:

For figure out the optimal life span of germplasm preserved in vitro, it is necessary to understand whether its propagating ability changes or not after subcultured for years. The shoot multiplication ability, adventitious root regeneration rate from shoots, and adventitious bud regeneration rate from leaves of ‘Fuji’, ‘Golden Delicious’, ‘Jonagold’ and ‘Gala’ apple in vitro shoot explants were studied. The results showed that it was lower that the shoot multiplication ability of ‘Fuji’, ‘Golden Delicious’ and ‘Jonagold’, the adventitious root regeneration rate of ‘Gala’, and the adventitious bud regeneration rate from leaves of ‘Golden Delicious’ , ‘Fuji’, and ‘Gala’ during the first four years after inoculation from field, that was at the stage of subculture from 24 to 40 times. With the increasing of the subculture times, the abilities for the given cultivars could increase and keep at a higher level stably. The apple explants repeatedly subcultured in vitro for years (25 years for ‘Fuji’, 19 years for ‘Golden Delicious’ and ‘Jonagold’, and 10 years for ‘Gala’) could remain their organogenesis characteristics.