The transcription factor CBF gene, which was considered to related to cold hardness induction, was transferred into apple stock M_(26) and cultivar of Gala via Agrobacterium tumefaciens of strain EHA 105. The adventitious bud regeneration system and genetic transformation system have been modified by studying the effect of explant's types and status on the efficiency of regeneration and transformation, and the transgenic lines were obtained. The main results were as followed.1. The efficiency of adventitiou...