Abstract: By using calli from leaves of Xueqing pear ( Pyrus sp. ) as explants, the Cry1Ac gene regula
ted by CaMV35S promoter was introduced into Xueqing pear through Ag robacterium-mediated transformation.
After co-culturing 698 calli and 231 Kan^r buds, respectively, with A. tum efaciens strain LBA4404 harboring a
plasmid pBX203 for 3 days and transferred to the selective medium containing 50 mg·L^-1 kanamycin for 30
days at a 15-day interval, 34.24% kanamycin2resistant (Kan^r ) buds ( adventitious shoots) regenerated on MS
+ 5 mg·L^-1 6-BA + 0.1 mg·L^-1 IAA and 15.58% of Kan^r buds rooted on 1/2 MS + 2 mg·L^-1 IBA + 0.5
mg·L^-1 6-BA + 500 mg·L^-1 AC. A total of 32 plants were obtained, but only 4 p lants were confirmed by
PCR and Southern-blot analysis that the Cry1Ac gene was transferred and integrated into the genome of
Xueqing pear.

Key words: Pear, Agrobacterium tumefaciens, Cry1Ac gene, Genetic transformation