Abstract: Establishment of an in vitro rapid propagation system using scale buds of Itoh hybrids 'He Xie' as materials, can overcome its shortcomings of the traditional breeding methods, accelerate the breeding and promotion of excellent Ito hybrid varieties. In this study, the buds of 'He Xie' was used as explants, different factors including treatments of disinfection time, PGRs concentration and root induction time, and different rooted seedling grades were investigated for the respectively effects on the initiation, proliferation, rooting and domestication of 'He Xie' by using one-way experimental design. The results showed that the optimal disinfection time of buds by 2% sodium hypochlorite solution was 12 min, and the contamination rate was 9.09%; the optimal initial culture medium was MS + 1.5 mg•L^-1 6-BA + 0.2 mg•L^-1 GA₃ + 0.5 mg•L^-1 +AgNO₃; the optimal proliferation culture medium was MS + 450 mg•L^-1 CaCl₂ + 0.5 mg•L^-1 6-BA + 0.2 mg•L^-1 IBA + 0.2 mg•L^-1 GA₃ + 0.5 mg•L^-1 AgNO₃ with a proliferation rate of 3.3; rootless seedlings were cultured on root induction medium 1/2 MS + 1.0 mg•L^-1 putrescine + 2.0 mg•L^-1 IBA for 8 d at 4°C in dark with refrigeration and then 30 d at room temperature in light, further transferred to root formation medium 1/2 MS + 1.0 g•L^-1 AC, after being cultured 20 d, the rooting rate was 66.7%. Then, Seedlings were transplanted on a substrate of perlite: vermiculite: charcoal soil = 1:1:1 (v/v/v), with the highest transplant survival rate of 52.0% for first-grade rooted seedlings after 60 days of transplanting, while most of the second- and third-grade seedlings were dead, suggesting that the quality of rooting is critical for transplant survival.

Key words: Ito 'He Xie',  initiation and proliferation,  rooting,  scale buds,  transplant domestication