Abstract: In this study, the seed embryos of Pyrus calleryana cv. ‘Cleveland’ were used as materials to systematically study the sterilization of seed embryo explants, callus induction, adventitious bud proliferation and rooting medium. The results showed that the germination rate of young embryos stored at 4°C for 21 d was the highest (67.23%) The suitable sterilization treatment of seed embryo explants was 75% alcohol (30 s)+10% H₂O₂ (10 min)+0.1% HgCl₂ (14 min)_. The most suitable medium for seed embryo germination was 1/2MS+4.0 mg·L^-1 6-BA+0.5 mg·L^-1 NAA, and the germination rate was 89.67%. The optimum culture medium for callus induction was 1/2MS+1.0 mg·L^-1 IBA+1.0 mg·L^-1 6-BA, and the callus induction rate was 93.33%. The best differentiation medium was 1/2MS+0.2 mg·L^-1 IBA+2.0 mg·L^-1 6-BA, and the regeneration frequency was 87.44%. Best transgenerational proliferation medium was 1/2MS+1.5 mg·L^-1 6-BA+0.1 mg·L^-1 IBA, and the proliferation rate was 100%. The most suitable medium for root formation was 1/2MS+ 20 g·L^-1 sucrose+1.0 g·L^-1 active carbon+1.5 mg·L^-1 IBA+0.05 mg·L^-1 NAA, and the rooting rate was 82.63%. In summary, the seed embryo regeneration system of P. calleryang cv. ‘Cleveland’ was established, which provides scientific basis and guidan-ce for the efficient reproduction of high-quality pear germplasm resources.

Key words: Pyrus calleryana cv. ‘Cleveland’, embryo rescue, tissue culture, regeneration system